Added tests and for-of/for-in down-leveling

src/compiler/checker.ts

@@ -15818,8 +15818,8 @@ namespace ts {
             }
             let leftType = checkExpression(left, contextualMapper);
             let rightType = checkExpression(right, contextualMapper);
-            let propagateNull = operator >= SyntaxKind.FirstAssignment && operator <= SyntaxKind.LastAssignment && left.flags & NodeFlags.PropagateNull;
-            let propagatingType = propagateNull ? getNullPropagatingType(leftType) : neverType;
+            const propagateNull = operator >= SyntaxKind.FirstAssignment && operator <= SyntaxKind.LastAssignment && left.flags & NodeFlags.PropagateNull;
+            const propagatingType = propagateNull ? getNullPropagatingType(leftType) : neverType;
             if (propagateNull) {
                 leftType = getNonNullableType(leftType);
             }

src/compiler/factory.ts

@@ -2376,12 +2376,21 @@ namespace ts {
         }
     }
 
-    export function insertLeadingStatement(dest: Statement, source: Statement) {
-        if (isBlock(dest)) {
-            return updateBlock(dest, setTextRange(createNodeArray([source, ...dest.statements]), dest.statements));
+    export function insertLeadingStatement(embeddedStatement: Statement, newStatement: Statement) {
+        if (isBlock(embeddedStatement)) {
+            return updateBlock(
+                embeddedStatement,
+                setTextRange(
+                    createNodeArray([newStatement, ...embeddedStatement.statements]),
+                    embeddedStatement.statements
+                )
+            );
         }
         else {
-            return createBlock(createNodeArray([dest, source]), /*multiLine*/ true);
+            return createBlock(
+                createNodeArray([newStatement, embeddedStatement]),
+                /*multiLine*/ true
+            );
         }
     }
 
@@ -2402,67 +2411,28 @@ namespace ts {
         return updated;
     }
 
-    export const enum CreateRefFlags {
-        Readable = 1 << 0,
-        Writable = 1 << 1,
-        ReadWrite = Readable | Writable,
-    }
-
     /**
-     * Creates an expression that can be used to bind a reference to an identifier or property.
+     * Creates an expression that can be used to bind a reference to an identifier, property access, or element access.
      *
-     * For an identifier `x`, this creates an expression similar to the following:
+     * This creates an expression similar to the following:
      *
      *    ({
      *        get value() { return x; },
      *        set value(_a) { x = _a; }
      *    })
      *
-     * For a property `x.y`, this creates an expression similar to the following:
-     *
-     *    (_a = x, {
-     *        get value() { return _a.y; },
-     *        set value(_b) { _a.y = _b; }
-     *    })
-     *
-     * For an element access `x[y()]`, this creates an expression similar to the following:
-     *
-     *    (_a = x, _b = y(), {
-     *        get value() { return _a[_b]; },
-     *        set value(_c) { _a[_b] = _c; }
-     *    })
+     * @param node The referenced expression.
+     * @param recordTempVariable A callback used to record temporary variables.
+     * @param writeOnly A value indicating whether to omit the `value` getter on the ref object.
      */
-    export function createRef(node: PropertyAccessExpression | ElementAccessExpression | Identifier, recordTempVariable: (node: Identifier) => void, flags?: CreateRefFlags) {
-        if (!flags) flags = CreateRefFlags.ReadWrite;
-        const paramName = flags & CreateRefFlags.Writable ? createTempVariable(/*recordTempVariable*/ undefined) : undefined;
-        let expressions: Expression[];
-        let getValue: Expression;
-        let putValue: Expression;
-        if (isPropertyAccessOrElementAccess(node)) {
-            expressions = [];
-            const { reference } = createPropertyReference(node, recordTempVariable, expressions, /*captureArgumentExpression*/ true);
-            // Copy null propagation flags
-            if (node.flags & NodeFlags.PropagateNull) {
-                reference.flags |= NodeFlags.PropagateNull;
-            }
-            if (flags & CreateRefFlags.Readable) {
-                getValue = reference
-            }
-            if (flags & CreateRefFlags.Writable) {
-                putValue = setSourceMapRange(createAssignment(reference, paramName), node);
-            }
-        }
-        else {
-            if (flags & CreateRefFlags.Readable) {
-                getValue = node;
-            }
-            if (flags & CreateRefFlags.Writable) {
-                putValue = setSourceMapRange(createAssignment(node, paramName), node);
-            }
-        }
-
+    export function createRefObject(node: PropertyAccessExpression | ElementAccessExpression | Identifier, recordTempVariable: (temp: Identifier) => void, writeOnly?: boolean) {
+        const expressions: Expression[] = [];
+        const paramName = createTempVariable(/*recordTempVariable*/ undefined);
+        const reference = isPropertyAccessOrElementAccess(node)
+            ? createPropertyReference(node, recordTempVariable, expressions, /*captureIdentifiers*/ false, /*captureArgumentExpression*/ true, /*copyNullPropagation*/ true).reference
+            : node;
         const properties: ObjectLiteralElementLike[] = [];
-        if (getValue) {
+        if (!writeOnly) {
             properties.push(
                 setSourceMapRange(
                     createGetAccessor(
@@ -2471,38 +2441,34 @@ namespace ts {
                         "value",
                         /*parameters*/ [],
                         /*type*/ undefined,
-                        createBlock([setSourceMapRange(createReturn(getValue), node)])
+                        createBlock([setSourceMapRange(createReturn(reference), node)])
                     ),
                     node
                 )
             );
         }
-        if (putValue) {
-            properties.push(
-                setSourceMapRange(
-                    createSetAccessor(
-                        /*decorators*/ undefined,
-                        /*modifiers*/ undefined,
-                        "value",
-                        [createParameter(/*decorators*/ undefined, /*modifiers*/ undefined, /*dotDotDotToken*/ undefined, paramName)],
-                        createBlock([setSourceMapRange(createStatement(putValue), node)])
-                    ),
-                    node
-                )
-            );
-        }
-        const refExpression = setSourceMapRange(
-            setCommentRange(
-                createObjectLiteral(properties, /*multiLine*/ false),
+        properties.push(
+            setSourceMapRange(
+                createSetAccessor(
+                    /*decorators*/ undefined,
+                    /*modifiers*/ undefined,
+                    "value",
+                    [createParameter(/*decorators*/ undefined, /*modifiers*/ undefined, /*dotDotDotToken*/ undefined, paramName)],
+                    createBlock([setSourceMapRange(createStatement(setSourceMapRange(createAssignment(reference, paramName), node)), node)])
+                ),
                 node
-            ),
-            node
+            )
         );
-        if (expressions) {
-            expressions.push(refExpression);
-            return inlineExpressions(expressions);
-        }
-        return refExpression;
+        expressions.push(
+            setSourceMapRange(
+                setCommentRange(
+                    createObjectLiteral(properties, /*multiLine*/ false),
+                    node
+                ),
+                node
+            )
+        );
+        return setTextRange(inlineExpressions(expressions), node);
     }
 
     /**
@@ -2518,6 +2484,7 @@ namespace ts {
             case SyntaxKind.Identifier:
                 return captureIdentifiers;
             case SyntaxKind.ThisKeyword:
+            case SyntaxKind.SuperKeyword:
             case SyntaxKind.NullKeyword:
             case SyntaxKind.TrueKeyword:
             case SyntaxKind.FalseKeyword:
@@ -2566,39 +2533,77 @@ namespace ts {
     export interface PropertyReference {
         baseValue: Expression;
         reference: PropertyAccessExpression | ElementAccessExpression;
+        thisValue?: Expression;
     }
 
     /**
      * Creates an approximation of an ECMAScript `Reference` specification type.
-     * @param lhsReference The property or element access expression from which to create the reference.
+     * @param referenceExpression The expression from which to create the reference.
      * @param recordTempVariable A callback used to record new temp variables.
-     * @param expressions The array of expressions into which capturing assignments should be added.
-     * @param captureArgumentExpression A value indicating whether to capture the argumentExpression of an ElementAccessExpression.
+     * @param expressions The array of expressions into which capturing assignments should be
+     * added. If not supplied, expression capturing occurs in-line in the reference.
+     * @param captureArgumentExpression A value indicating whether to capture the
+     * argumentExpression of an ElementAccessExpression.
+     * @param copyNullPropagation A value indicating whether to preserve null propagation flags.
      */
-    export function createPropertyReference(referenceExpression: PropertyAccessExpression | ElementAccessExpression, recordTempVariable: (temp: Identifier) => void, expressions: Expression[], captureArgumentExpression?: boolean): PropertyReference {
-        const baseValue = captureExpressionIfNeeded(referenceExpression.expression, recordTempVariable, expressions);
-        let reference: PropertyAccessExpression | ElementAccessExpression;
-        if (isPropertyAccessExpression(referenceExpression)) {
-            reference = setTextRange(
-                createPropertyAccess(
-                    baseValue,
-                    referenceExpression.name
-                ),
-                referenceExpression
-            );
+    export function createPropertyReference(node: PropertyAccessExpression | ElementAccessExpression, recordTempVariable: (temp: Identifier) => void, expressions?: Expression[], captureIdentifiers?: boolean, captureArgumentExpression?: boolean, copyNullPropagation?: boolean): PropertyReference {
+        let baseExpression: Expression = node.expression;
+        let baseValue = baseExpression;
+        let reference = node;
+        let thisValue: Expression;
+        if (shouldBeCapturedInTempVariable(baseExpression, captureIdentifiers)) {
+            if (expressions) {
+                baseValue = baseExpression = captureExpression(baseValue, recordTempVariable, expressions);
+            }
+            else {
+                baseValue = createTempVariable(recordTempVariable);
+                baseExpression = setTextRange(createAssignment(baseValue, baseExpression), baseExpression);
+            }
+        }
+        if (isPropertyAccessExpression(node)) {
+            reference = updatePropertyAccess(node, baseExpression, node.name);
         }
         else {
-            reference = setTextRange(
-                createElementAccess(
-                    baseValue,
-                    captureArgumentExpression
-                        ? captureExpressionIfNeeded(referenceExpression.argumentExpression, recordTempVariable, expressions)
-                        : referenceExpression.argumentExpression
-                ),
-                referenceExpression
+            let argumentExpression = node.argumentExpression;
+            let argumentValue = argumentExpression;
+            if (captureArgumentExpression && shouldBeCapturedInTempVariable(argumentExpression, captureIdentifiers)) {
+                if (expressions) {
+                    argumentValue = argumentExpression = captureExpression(argumentExpression, recordTempVariable, expressions);
+                }
+                else {
+                    argumentValue = createTempVariable(recordTempVariable);
+                    argumentExpression = setTextRange(createAssignment(argumentValue, argumentExpression), argumentExpression);
+                    baseExpression = baseValue === baseExpression
+                        ? inlineExpressions([argumentExpression, baseValue]) // simple literal or identifier
+                        : inlineExpressions([baseExpression, argumentExpression, baseValue]); // complex expression
+                }
+            }
+            reference = updateElementAccess(
+                node,
+                baseExpression,
+                argumentValue
             );
         }
-        return { baseValue, reference };
+        if (reference === node && !copyNullPropagation && reference.flags & NodeFlags.PropagateNull) {
+            reference = setTextRange(
+                isPropertyAccessExpression(reference)
+                    ? createPropertyAccess(
+                        reference.expression,
+                        reference.name,
+                        copyNullPropagation ? node.flags & NodeFlags.PropagateNull : 0
+                    )
+                    : createElementAccess(
+                        reference.expression,
+                        reference.argumentExpression,
+                        copyNullPropagation ? node.flags & NodeFlags.PropagateNull : 0
+                    ),
+                node
+            );
+        }
+        if (node.expression.kind === SyntaxKind.SuperKeyword) {
+            thisValue = createThis();
+        }
+        return { baseValue, reference, thisValue };
     }
 
     export interface CallBinding {
@@ -2618,9 +2623,16 @@ namespace ts {
         const callee = skipOuterExpressions(expression);
         let thisArg: Expression;
         let target: LeftHandSideExpression;
-        if (isSuperProperty(callee)) {
-            thisArg = createThis();
-            target = callee;
+        if (isPropertyAccessOrElementAccess(callee)) {
+            const { baseValue, reference, thisValue } = createPropertyReference(
+                callee,
+                recordTempVariable,
+                /*expressions*/ undefined,
+                captureIdentifiers,
+                /*captureArgumentExpression*/ false,
+                /*copyNullPropagation*/ true);
+            thisArg = thisValue || baseValue;
+            target = reference;
         }
         else if (isSuper(callee)) {
             thisArg = createThis();
@@ -2632,54 +2644,6 @@ namespace ts {
             thisArg = createVoidZero();
             target = parenthesizeForAccess(callee);
         }
-        else if (isPropertyAccessExpression(callee)) {
-            if (shouldBeCapturedInTempVariable(callee.expression, captureIdentifiers)) {
-                // for `a.b()` target is `(_a = a).b` and thisArg is `_a`
-                thisArg = createTempVariable(recordTempVariable);
-                target = setTextRange(
-                    createPropertyAccess(
-                        setTextRange(
-                            createAssignment(
-                                thisArg,
-                                callee.expression
-                            ),
-                            callee.expression
-                        ),
-                        callee.name,
-                        callee.flags & NodeFlags.PropagateNull
-                    ),
-                    callee
-                );
-            }
-            else {
-                thisArg = callee.expression;
-                target = callee;
-            }
-        }
-        else if (isElementAccessExpression(callee)) {
-            if (shouldBeCapturedInTempVariable(callee.expression, captureIdentifiers)) {
-                // for `a[b]()` target is `(_a = a)[b]` and thisArg is `_a`
-                thisArg = createTempVariable(recordTempVariable);
-                target = setTextRange(
-                    createElementAccess(
-                        setTextRange(
-                            createAssignment(
-                                thisArg,
-                                callee.expression
-                            ),
-                            callee.expression
-                        ),
-                        callee.argumentExpression,
-                        callee.flags & NodeFlags.PropagateNull
-                    ),
-                    callee
-                );
-            }
-            else {
-                thisArg = callee.expression;
-                target = callee;
-            }
-        }
         else {
             // for `a()` target is `a` and thisArg is `void 0`
             thisArg = createVoidZero();

src/compiler/transformers/esnext.ts

@@ -79,6 +79,8 @@ namespace ts {
                     return visitVariableDeclaration(node as VariableDeclaration);
                 case SyntaxKind.ForOfStatement:
                     return visitForOfStatement(node as ForOfStatement, /*outermostLabeledStatement*/ undefined);
+                case SyntaxKind.ForInStatement:
+                    return visitForInStatement(node as ForInStatement, /*outermostLabeledStatement*/ undefined);
                 case SyntaxKind.ForStatement:
                     return visitForStatement(node as ForStatement);
                 case SyntaxKind.VoidExpression:
@@ -160,8 +162,11 @@ namespace ts {
         function visitLabeledStatement(node: LabeledStatement) {
             if (enclosingFunctionFlags & FunctionFlags.Async && enclosingFunctionFlags & FunctionFlags.Generator) {
                 const statement = unwrapInnermostStatementOfLabel(node);
-                if (statement.kind === SyntaxKind.ForOfStatement && (<ForOfStatement>statement).awaitModifier) {
-                    return visitForOfStatement(<ForOfStatement>statement, node);
+                switch (statement.kind) {
+                    case SyntaxKind.ForOfStatement:
+                        return visitForOfStatement(<ForOfStatement>statement, /*outermostLabeledStatement*/ node);
+                    case SyntaxKind.ForInStatement:
+                        return visitForInStatement(<ForInStatement>statement, /*outermostLabeledStatement*/ node);
                 }
                 return restoreEnclosingLabel(visitEachChild(node, visitor, context), node);
             }
@@ -262,7 +267,7 @@ namespace ts {
                 case SyntaxKind.PropertyAccessExpression:
                 case SyntaxKind.ElementAccessExpression:
                     if (node.flags & NodeFlags.PropagateNull) {
-                        const ref = createRef(<PropertyAccessExpression | ElementAccessExpression>node, hoistVariableDeclaration, CreateRefFlags.Writable);
+                        const ref = createRefObject(<PropertyAccessExpression | ElementAccessExpression>node, hoistVariableDeclaration, /*writeOnly*/ true);
                         return setTextRange(createPropertyAccess(ref, "value"), node);
                     }
 
@@ -389,6 +394,9 @@ namespace ts {
             if (node.initializer.transformFlags & TransformFlags.ContainsObjectRest) {
                 node = transformForOfStatementWithObjectRest(node);
             }
+            if (isPropertyAccessOrElementAccess(node.initializer) && node.initializer.flags & NodeFlags.PropagateNull) {
+                node = transformForOfStatementWithNullPropagatingInitializer(node, node.initializer);
+            }
             if (node.awaitModifier) {
                 return transformForAwaitOfStatement(node, outermostLabeledStatement);
             }
@@ -434,6 +442,39 @@ namespace ts {
             return node;
         }
 
+        function transformForOfStatementWithNullPropagatingInitializer(node: ForOfStatement, initializer: PropertyAccessExpression | ElementAccessExpression) {
+            if (languageVersion >= ScriptTarget.ES2015) {
+                return updateForOf(
+                    node,
+                    node.awaitModifier,
+                    createPropertyAccess(createRefObject(initializer, hoistVariableDeclaration, /*writeOnly*/ true), "value"),
+                    node.expression,
+                    node.statement
+                );
+            }
+            else {
+                const temp = createTempVariable(hoistVariableDeclaration);
+                return updateForOf(
+                    node,
+                    node.awaitModifier,
+                    createVariableDeclarationList([createVariableDeclaration(temp)]),
+                    node.expression,
+                    insertLeadingStatement(
+                        node.statement,
+                        setTextRange(
+                            createStatement(
+                                setTextRange(
+                                    createAssignment(initializer, temp),
+                                    node.initializer
+                                )
+                            ),
+                            node.initializer
+                        )
+                    )
+                );
+            }
+        }
+
         function convertForOfStatementHead(node: ForOfStatement, boundValue: Expression) {
             const binding = createForOfBindingStatement(node.initializer, boundValue);
 
@@ -580,6 +621,48 @@ namespace ts {
             );
         }
 
+        function visitForInStatement(node: ForInStatement, outermostLabeledStatement: LabeledStatement): VisitResult<Statement> {
+            if (isPropertyAccessOrElementAccess(node.initializer) && node.initializer.flags & NodeFlags.PropagateNull) {
+                node = transformForInStatementWithNullPropagatingInitializer(node, node.initializer);
+            }
+
+            return restoreEnclosingLabel(visitEachChild(node, visitor, context), outermostLabeledStatement);
+        }
+
+        function transformForInStatementWithNullPropagatingInitializer(node: ForInStatement, initializer: PropertyAccessExpression | ElementAccessExpression) {
+            if (languageVersion >= ScriptTarget.ES5) {
+                return updateForIn(
+                    node,
+                    createPropertyAccess(createRefObject(initializer, hoistVariableDeclaration, /*writeOnly*/ true), "value"),
+                    node.expression,
+                    node.statement
+                );
+            }
+            else {
+                const temp = createTempVariable(hoistVariableDeclaration);
+                return updateForIn(
+                    node,
+                    createVariableDeclarationList([createVariableDeclaration(temp)]),
+                    node.expression,
+                    insertLeadingStatement(
+                        node.statement,
+                        setTextRange(
+                            createStatement(
+                                setTextRange(
+                                    createAssignment(
+                                        initializer,
+                                        temp
+                                    ),
+                                    node.initializer
+                                )
+                            ),
+                            node.initializer
+                        )
+                    )
+                );
+            }
+        }
+
         function visitParameter(node: ParameterDeclaration): ParameterDeclaration {
             if (node.transformFlags & TransformFlags.ContainsObjectRest) {
                 // Binding patterns are converted into a generated name and are
@@ -982,7 +1065,7 @@ namespace ts {
                     setTextRange(
                         createConditional(
                             createEquality(baseValue, createNull()),
-                            createVoidZero(),
+                            node.kind === SyntaxKind.DeleteExpression ? createTrue() : createVoidZero(),
                             updateNode(
                                 node,
                                 reference

src/services/services.ts

@@ -334,7 +334,7 @@ namespace ts {
         _primaryExpressionBrand: any;
         _memberExpressionBrand: any;
         _leftHandSideExpressionBrand: any;
-        _incrementExpressionBrand: any;
+        _updateExpressionBrand: any;
         _unaryExpressionBrand: any;
         _expressionBrand: any;
         constructor(_kind: SyntaxKind.Identifier, pos: number, end: number) {

tests/baselines/reference/emitter.safeNavigation.es2015.js

@@ -0,0 +1,716 @@
+//// [tests/cases/conformance/emitter/es2015/safeNavigation/emitter.safeNavigation.es2015.ts] ////
+
+//// [declarations.d.ts]
+declare var x: any;
+declare var y: any;
+declare var f: ({
+    (): void;
+    <T>(): void;
+    new (): any;
+    new <T>(): any;
+}) | undefined;
+declare var o: { y: typeof f; }
+declare class Base { x(): any; }
+declare namespace M {
+    export class y {}
+    export class z<T> {}
+}
+//// [propertyAccessOk.ts]
+x.y
+x?.y
+x?.y.z
+x.y?.z
+x?.y?.z
+//// [elementAccessOk.ts]
+x["y"]
+x?.["y"]
+x?.["y"]["z"]
+x["y"]?.["z"]
+x?.["y"]?.["z"]
+//// [callExpressionOk.ts]
+x()
+x?.()
+x.y?.()
+x["y"]?.()
+f?.<number>()
+o.y?.<number>()
+o["y"]?.<number>()
+//// [newExpressionOk.ts]
+new x()
+new x.y?.()
+new x["y"]?.()
+new f?.<number>()
+new o.y?.<number>()
+new o["y"]?.<number>()
+//// [mixedOk.ts]
+x?.y?.["z"]
+x?.["y"]?.z
+x?.y()
+x?.y?.()
+o?.y<number>()
+o?.y?.<number>()
+x?.["z"]()
+x?.["z"]?.()
+o?.["y"]<number>()
+o?.["y"]?.<number>()
+//// [mutationOk.ts]
+x?.y = 1
+x?.y += 1;
+x?.y -= 1;
+x?.y *= 1;
+x?.y /= 1;
+x?.y %= 1;
+x?.y **= 1;
+x?.y |= 1;
+x?.y &= 1;
+x?.y ^= 1;
+x?.y <<= 1;
+x?.y >>= 1;
+x?.y >>>= 1;
+x?.y++;
+x?.y--;
+++x?.y;
+--x?.y;
+delete x?.y;
+x?.["y"] = 1
+x?.["y"] += 1;
+x?.["y"] -= 1;
+x?.["y"] *= 1;
+x?.["y"] /= 1;
+x?.["y"] %= 1;
+x?.["y"] **= 1;
+x?.["y"] |= 1;
+x?.["y"] &= 1;
+x?.["y"] ^= 1;
+x?.["y"] <<= 1;
+x?.["y"] >>= 1;
+x?.["y"] >>>= 1;
+x?.["y"]++;
+x?.["y"]--;
+++x?.["y"];
+--x?.["y"];
+delete x?.["y"];
+//// [arrayAssignmentPatternOk.ts]
+[x?.y] = [1];
+[x?.["y"]] = [1];
+[...x?.y] = [1];
+[...x?.["y"]] = [1];
+//// [objectAssignmentPatternOk.ts]
+({ a: x?.y } = { a: 1 });
+({ a: x?.["y"] } = { a: 1 });
+//// [questionDotDigitIsConditionalOk.ts]
+x?.3:1;
+//// [superPropertyInvocationOk.ts]
+// supported for invocation of super property
+void class extends Base {
+    m() {
+        super.x?.();
+        super["x"]?.();
+    }
+}
+
+//// [generalParsingOk.ts]
+// object literals
+// - computed property names
+void { [x?.y]: 1 }
+void { [x?.["y"]]: 1 }
+void { [x?.()]: 1 }
+void { [new x?.()]: 1 }
+// - property assignments
+void { a: x?.y }
+void { a: x?.["y"] }
+void { a: x?.() }
+void { a: new x?.() }
+
+// classes
+// - computed property names
+// void class { [x?.y] = 1 }        // legal parse, but causes a checker error
+// void class { [x?.["y"]] = 1 }    // legal parse, but causes a checker error
+// void class { [x?.()] = 1 }       // legal parse, but causes a checker error
+// void class { [new f?.()] = 1 }   // legal parse, but causes a checker error
+void class { [Symbol?.toStringTag] = "" }
+// - property declarations
+void class { a = x?.y }
+void class { a = x?.["y"] }
+void class { a = x?.() }
+void class { a = new x?.() }
+// - heritage clauses
+void class extends M?.y {}
+void class extends M?.["y"] {}
+void class extends M?.z<number> {}
+// - class decorators
+@x?.y class C1 {}
+@x?.["y"] class C2 {}
+@x?.() class C3 {}
+@new x?.() class C4 {}
+// - member decorators
+class C5 { @x?.y m() {} }
+class C6 { @x?.["y"] m() {} } // allowed as ?.[ is not ambiguous with computed property names
+class C7 { @x?.() m() {} }
+class C8 { @new x?.() m () {} }
+// - parameter decorators
+class C9 { m(@x?.y a) {} }
+class C10 { m(@x?.["y"] a) {} }
+class C11 { m(@x?.() a) {} }
+class C12 { m(@new x?.() a) {} }
+
+// functions
+// - parameters
+void function (a = x?.y) {}
+void function (a = x?.["y"]) {}
+void function (a = x?.()) {}
+void function (a = new x?.()) {}
+// - binding elements
+//   - initializers
+void function ({ a = x?.y }) {}
+void function ({ a = x?.["y"] }) {}
+void function ({ a = x?.() }) {}
+void function ({ a = new x?.() }) {}
+//   - computed properties
+void function ({ [x?.y]: a }) {}
+void function ({ [x?.["y"]]: a }) {}
+void function ({ [x?.()]: a }) {}
+void function ({ [new x?.()]: a }) {}
+
+// arrow functions
+// - parameters
+((a = x?.y) => {});
+((a = x?.["y"]) => {});
+((a = x?.()) => {});
+((a = new x?.()) => {});
+// - expression bodies
+(() => x?.y);
+(() => x?.["y"]);
+(() => x?.());
+(() => new x?.());
+
+// parenthesis
+(x?.y);
+
+// comma
+x?.y, f();
+f(), x?.y;
+
+// conditional
+x?.y ? 0 : 1
+0 ? x?.y : 1;
+0 ? 1 : x?.y;
+
+// binary
+x?.y + 1;
+x?.y - 1;
+x?.y * 1;
+x?.y / 1;
+x?.y ** 1;
+x?.y % 1;
+x?.y ^ 1;
+x?.y & 1;
+x?.y | 1;
+x?.y << 1;
+x?.y >> 1;
+x?.y >>> 1;
+x?.y && 1;
+x?.y || 1;
+x?.y == 1;
+x?.y === 1;
+x?.y != 1;
+x?.y !== 1;
+x?.y < 1;
+x?.y <= 1;
+x?.y > 1;
+x?.y >= 1;
+1 + x?.y;
+1 - x?.y;
+1 * x?.y;
+1 / x?.y;
+1 ** x?.y;
+1 % x?.y;
+1 ^ x?.y;
+1 & x?.y;
+1 | x?.y;
+1 << x?.y;
+1 >> x?.y;
+1 >>> x?.y;
+1 && x?.y;
+1 || x?.y;
+1 == x?.y;
+1 === x?.y;
+1 != x?.y;
+1 !== x?.y;
+1 < x?.y;
+1 <= x?.y;
+1 > x?.y;
+1 >= x?.y;
+
+// prefix unary
++x?.y;
+-x?.y;
+!x?.y;
+~x?.y;
+
+// unary
+void x?.y;
+typeof x?.y;
+void function * () { yield x?.y; }
+void async function() { await x?.y; }
+
+// notnull
+x?.y!.z;
+
+// assertions
+<string>x?.y;
+x?.y as string;
+
+// array literals
+[x?.y];
+[, x?.y];
+[...x?.y];
+
+// literals
+1?.toString(); // no need for `..`
+1.?.toString();
+.0?.toString();
+4e3?.toString();
+1.e3?.toString();
+""?.toString();
+''?.toString();
+``?.toString();
+/./?.toString();
+/./g?.toString();
+true?.toString();
+false?.toString();
+
+// templates
+`${x?.y}`;
+
+// variables
+var v = x?.y;
+var [v] = x?.y;
+var [v = x?.y] = [1];
+var {v} = x?.y;
+var {v = x?.y} = {v:1};
+var {[x?.y]: v} = null;
+
+// if/else if
+if (x?.y) {}
+if (1) {} else if (x?.y) {}
+
+// switch
+switch (x?.y) {}
+switch (1) { case x?.y: break; }
+
+// do/while
+do {} while (x?.y)
+while (x?.y) {}
+
+// for
+for (x?.y; x?.y; x?.y);
+
+// for..in
+for (x?.y in {});
+
+// for..of
+for (x?.y of []);
+
+// enums
+enum E {
+    a = x?.y
+}
+
+//// [exportsOk.ts]
+export default x?.y;
+
+//// [propertyAccessOk.js]
+x.y;
+x == null ? void 0 : x.y;
+(x == null ? void 0 : x.y).z;
+(_a = x.y) == null ? void 0 : _a.z;
+(_b = x == null ? void 0 : x.y) == null ? void 0 : _b.z;
+var _a, _b;
+//// [elementAccessOk.js]
+x["y"];
+x == null ? void 0 : x["y"];
+(x == null ? void 0 : x["y"])["z"];
+(_a = x["y"]) == null ? void 0 : _a["z"];
+(_b = x == null ? void 0 : x["y"]) == null ? void 0 : _b["z"];
+var _a, _b;
+//// [callExpressionOk.js]
+x();
+x == null ? void 0 : x();
+(_a = x.y) == null ? void 0 : _a.call(x);
+(_b = x["y"]) == null ? void 0 : _b.call(x);
+f == null ? void 0 : f();
+(_c = o.y) == null ? void 0 : _c.call(o);
+(_d = o["y"]) == null ? void 0 : _d.call(o);
+var _a, _b, _c, _d;
+//// [newExpressionOk.js]
+new x();
+(_a = x.y) == null ? void 0 : new _a();
+(_b = x["y"]) == null ? void 0 : new _b();
+f == null ? void 0 : new f();
+(_c = o.y) == null ? void 0 : new _c();
+(_d = o["y"]) == null ? void 0 : new _d();
+var _a, _b, _c, _d;
+//// [mixedOk.js]
+(_a = x == null ? void 0 : x.y) == null ? void 0 : _a["z"];
+(_b = x == null ? void 0 : x["y"]) == null ? void 0 : _b.z;
+(x == null ? void 0 : x.y)();
+(_c = x == null ? void 0 : x.y) == null ? void 0 : _c.call(x);
+(o == null ? void 0 : o.y)();
+(_d = o == null ? void 0 : o.y) == null ? void 0 : _d.call(o);
+(x == null ? void 0 : x["z"])();
+(_e = x == null ? void 0 : x["z"]) == null ? void 0 : _e.call(x);
+(o == null ? void 0 : o["y"])();
+(_f = o == null ? void 0 : o["y"]) == null ? void 0 : _f.call(o);
+var _a, _b, _c, _d, _e, _f;
+//// [mutationOk.js]
+_a = 1, x == null ? _a : x.y = _a;
+_b = 1, x == null ? _b : x.y += _b;
+_c = 1, x == null ? _c : x.y -= _c;
+_d = 1, x == null ? _d : x.y *= _d;
+_e = 1, x == null ? _e : x.y /= _e;
+_f = 1, x == null ? _f : x.y %= _f;
+_g = 1, x == null ? _g : (_h = x).y = Math.pow(_h.y, _g);
+_j = 1, x == null ? _j : x.y |= _j;
+_k = 1, x == null ? _k : x.y &= _k;
+_l = 1, x == null ? _l : x.y ^= _l;
+_m = 1, x == null ? _m : x.y <<= _m;
+_o = 1, x == null ? _o : x.y >>= _o;
+_p = 1, x == null ? _p : x.y >>>= _p;
+x == null ? void 0 : x.y++;
+x == null ? void 0 : x.y--;
+x == null ? void 0 : ++x.y;
+x == null ? void 0 : --x.y;
+x == null ? true : delete x.y;
+_q = 1, x == null ? _q : x["y"] = _q;
+_r = 1, x == null ? _r : x["y"] += _r;
+_s = 1, x == null ? _s : x["y"] -= _s;
+_t = 1, x == null ? _t : x["y"] *= _t;
+_u = 1, x == null ? _u : x["y"] /= _u;
+_v = 1, x == null ? _v : x["y"] %= _v;
+_w = 1, x == null ? _w : (_x = x)[_y = "y"] = Math.pow(_x[_y], _w);
+_z = 1, x == null ? _z : x["y"] |= _z;
+_0 = 1, x == null ? _0 : x["y"] &= _0;
+_1 = 1, x == null ? _1 : x["y"] ^= _1;
+_2 = 1, x == null ? _2 : x["y"] <<= _2;
+_3 = 1, x == null ? _3 : x["y"] >>= _3;
+_4 = 1, x == null ? _4 : x["y"] >>>= _4;
+x == null ? void 0 : x["y"]++;
+x == null ? void 0 : x["y"]--;
+x == null ? void 0 : ++x["y"];
+x == null ? void 0 : --x["y"];
+x == null ? true : delete x["y"];
+var _a, _b, _c, _d, _e, _f, _g, _j, _k, _l, _m, _o, _p, _q, _r, _s, _t, _u, _v, _w, _z, _0, _1, _2, _3, _4;
+var _h, _x, _y;
+//// [arrayAssignmentPatternOk.js]
+[{ set value(_a) { x == null ? _a : x.y = _a; } }.value] = [1];
+[{ set value(_a) { x == null ? _a : x["y"] = _a; } }.value] = [1];
+[...{ set value(_a) { x == null ? _a : x.y = _a; } }.value] = [1];
+[...{ set value(_a) { x == null ? _a : x["y"] = _a; } }.value] = [1];
+//// [objectAssignmentPatternOk.js]
+({ a: { set value(_a) { x == null ? _a : x.y = _a; } }.value } = { a: 1 });
+({ a: { set value(_a) { x == null ? _a : x["y"] = _a; } }.value } = { a: 1 });
+//// [questionDotDigitIsConditionalOk.js]
+x ? .3 : 1;
+//// [superPropertyInvocationOk.js]
+// supported for invocation of super property
+void class extends Base {
+    m() {
+        (_a = super.x) == null ? void 0 : _a.call(this);
+        (_b = super["x"]) == null ? void 0 : _b.call(this);
+        var _a, _b;
+    }
+};
+//// [generalParsingOk.js]
+var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
+    var c = arguments.length, r = c < 3 ? target : desc === null ? desc = Object.getOwnPropertyDescriptor(target, key) : desc, d;
+    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") r = Reflect.decorate(decorators, target, key, desc);
+    else for (var i = decorators.length - 1; i >= 0; i--) if (d = decorators[i]) r = (c < 3 ? d(r) : c > 3 ? d(target, key, r) : d(target, key)) || r;
+    return c > 3 && r && Object.defineProperty(target, key, r), r;
+};
+var __param = (this && this.__param) || function (paramIndex, decorator) {
+    return function (target, key) { decorator(target, key, paramIndex); }
+};
+var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    return new (P || (P = Promise))(function (resolve, reject) {
+        function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
+        function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
+        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        step((generator = generator.apply(thisArg, _arguments || [])).next());
+    });
+};
+// object literals
+// - computed property names
+void { [x == null ? void 0 : x.y]: 1 };
+void { [x == null ? void 0 : x["y"]]: 1 };
+void { [x == null ? void 0 : x()]: 1 };
+void { [x == null ? void 0 : new x()]: 1 };
+// - property assignments
+void { a: x == null ? void 0 : x.y };
+void { a: x == null ? void 0 : x["y"] };
+void { a: x == null ? void 0 : x() };
+void { a: x == null ? void 0 : new x() };
+// classes
+// - computed property names
+// void class { [x?.y] = 1 }        // legal parse, but causes a checker error
+// void class { [x?.["y"]] = 1 }    // legal parse, but causes a checker error
+// void class { [x?.()] = 1 }       // legal parse, but causes a checker error
+// void class { [new f?.()] = 1 }   // legal parse, but causes a checker error
+void class {
+    constructor() {
+        this[Symbol == null ? void 0 : Symbol.toStringTag] = "";
+    }
+};
+// - property declarations
+void class {
+    constructor() {
+        this.a = x == null ? void 0 : x.y;
+    }
+};
+void class {
+    constructor() {
+        this.a = x == null ? void 0 : x["y"];
+    }
+};
+void class {
+    constructor() {
+        this.a = x == null ? void 0 : x();
+    }
+};
+void class {
+    constructor() {
+        this.a = x == null ? void 0 : new x();
+    }
+};
+// - heritage clauses
+void class extends (M == null ? void 0 : M.y) {
+};
+void class extends (M == null ? void 0 : M["y"]) {
+};
+void class extends (M == null ? void 0 : M.z) {
+};
+// - class decorators
+let C1 = class C1 {
+};
+C1 = __decorate([
+    x == null ? void 0 : x.y
+], C1);
+let C2 = class C2 {
+};
+C2 = __decorate([
+    x == null ? void 0 : x["y"]
+], C2);
+let C3 = class C3 {
+};
+C3 = __decorate([
+    x == null ? void 0 : x()
+], C3);
+let C4 = class C4 {
+};
+C4 = __decorate([
+    x == null ? void 0 : new x()
+], C4);
+// - member decorators
+class C5 {
+    m() { }
+}
+__decorate([
+    x == null ? void 0 : x.y
+], C5.prototype, "m", null);
+class C6 {
+    m() { }
+} // allowed as ?.[ is not ambiguous with computed property names
+__decorate([
+    x == null ? void 0 : x["y"]
+], C6.prototype, "m", null);
+class C7 {
+    m() { }
+}
+__decorate([
+    x == null ? void 0 : x()
+], C7.prototype, "m", null);
+class C8 {
+    m() { }
+}
+__decorate([
+    x == null ? void 0 : new x()
+], C8.prototype, "m", null);
+// - parameter decorators
+class C9 {
+    m(a) { }
+}
+__decorate([
+    __param(0, x == null ? void 0 : x.y)
+], C9.prototype, "m", null);
+class C10 {
+    m(a) { }
+}
+__decorate([
+    __param(0, x == null ? void 0 : x["y"])
+], C10.prototype, "m", null);
+class C11 {
+    m(a) { }
+}
+__decorate([
+    __param(0, x == null ? void 0 : x())
+], C11.prototype, "m", null);
+class C12 {
+    m(a) { }
+}
+__decorate([
+    __param(0, x == null ? void 0 : new x())
+], C12.prototype, "m", null);
+// functions
+// - parameters
+void function (a = x == null ? void 0 : x.y) { };
+void function (a = x == null ? void 0 : x["y"]) { };
+void function (a = x == null ? void 0 : x()) { };
+void function (a = x == null ? void 0 : new x()) { };
+// - binding elements
+//   - initializers
+void function ({ a = x == null ? void 0 : x.y }) { };
+void function ({ a = x == null ? void 0 : x["y"] }) { };
+void function ({ a = x == null ? void 0 : x() }) { };
+void function ({ a = x == null ? void 0 : new x() }) { };
+//   - computed properties
+void function ({ [x == null ? void 0 : x.y]: a }) { };
+void function ({ [x == null ? void 0 : x["y"]]: a }) { };
+void function ({ [x == null ? void 0 : x()]: a }) { };
+void function ({ [x == null ? void 0 : new x()]: a }) { }((a = x == null ? void 0 : x.y) => { });
+((a = x == null ? void 0 : x["y"]) => { });
+((a = x == null ? void 0 : x()) => { });
+((a = x == null ? void 0 : new x()) => { });
+// - expression bodies
+(() => x == null ? void 0 : x.y);
+(() => x == null ? void 0 : x["y"]);
+(() => x == null ? void 0 : x());
+(() => x == null ? void 0 : new x());
+// parenthesis
+(x == null ? void 0 : x.y);
+// comma
+x == null ? void 0 : x.y, f();
+f(), x == null ? void 0 : x.y;
+// conditional
+x == null ? void 0 : x.y ? 0 : 1;
+0 ? x == null ? void 0 : x.y : 1;
+0 ? 1 : x == null ? void 0 : x.y;
+// binary
+(x == null ? void 0 : x.y) + 1;
+(x == null ? void 0 : x.y) - 1;
+(x == null ? void 0 : x.y) * 1;
+(x == null ? void 0 : x.y) / 1;
+Math.pow((x == null ? void 0 : x.y), 1);
+(x == null ? void 0 : x.y) % 1;
+(x == null ? void 0 : x.y) ^ 1;
+(x == null ? void 0 : x.y) & 1;
+(x == null ? void 0 : x.y) | 1;
+(x == null ? void 0 : x.y) << 1;
+(x == null ? void 0 : x.y) >> 1;
+(x == null ? void 0 : x.y) >>> 1;
+(x == null ? void 0 : x.y) && 1;
+(x == null ? void 0 : x.y) || 1;
+(x == null ? void 0 : x.y) == 1;
+(x == null ? void 0 : x.y) === 1;
+(x == null ? void 0 : x.y) != 1;
+(x == null ? void 0 : x.y) !== 1;
+(x == null ? void 0 : x.y) < 1;
+(x == null ? void 0 : x.y) <= 1;
+(x == null ? void 0 : x.y) > 1;
+(x == null ? void 0 : x.y) >= 1;
+1 + (x == null ? void 0 : x.y);
+1 - (x == null ? void 0 : x.y);
+1 * (x == null ? void 0 : x.y);
+1 / (x == null ? void 0 : x.y);
+Math.pow(1, (x == null ? void 0 : x.y));
+1 % (x == null ? void 0 : x.y);
+1 ^ (x == null ? void 0 : x.y);
+1 & (x == null ? void 0 : x.y);
+1 | (x == null ? void 0 : x.y);
+1 << (x == null ? void 0 : x.y);
+1 >> (x == null ? void 0 : x.y);
+1 >>> (x == null ? void 0 : x.y);
+1 && (x == null ? void 0 : x.y);
+1 || (x == null ? void 0 : x.y);
+1 == (x == null ? void 0 : x.y);
+1 === (x == null ? void 0 : x.y);
+1 != (x == null ? void 0 : x.y);
+1 !== (x == null ? void 0 : x.y);
+1 < (x == null ? void 0 : x.y);
+1 <= (x == null ? void 0 : x.y);
+1 > (x == null ? void 0 : x.y);
+1 >= (x == null ? void 0 : x.y);
+// prefix unary
++(x == null ? void 0 : x.y);
+-(x == null ? void 0 : x.y);
+!(x == null ? void 0 : x.y);
+~(x == null ? void 0 : x.y);
+// unary
+void (x == null ? void 0 : x.y);
+typeof (x == null ? void 0 : x.y);
+void function* () { yield x == null ? void 0 : x.y; };
+void function () {
+    return __awaiter(this, void 0, void 0, function* () { yield (x == null ? void 0 : x.y); });
+};
+// notnull
+(x == null ? void 0 : x.y).z;
+// assertions
+x == null ? void 0 : x.y;
+x == null ? void 0 : x.y;
+// array literals
+[x == null ? void 0 : x.y];
+[, x == null ? void 0 : x.y];
+[...x == null ? void 0 : x.y];
+// literals
+((_a = 1) == null ? void 0 : _a.toString)(); // no need for `..`
+((_b = 1.) == null ? void 0 : _b.toString)();
+((_c = .0) == null ? void 0 : _c.toString)();
+((_d = 4e3) == null ? void 0 : _d.toString)();
+((_e = 1.e3) == null ? void 0 : _e.toString)();
+((_f = "") == null ? void 0 : _f.toString)();
+((_g = '') == null ? void 0 : _g.toString)();
+((_h = ``) == null ? void 0 : _h.toString)();
+((_j = /./) == null ? void 0 : _j.toString)();
+((_k = /./g) == null ? void 0 : _k.toString)();
+((_l = true) == null ? void 0 : _l.toString)();
+((_m = false) == null ? void 0 : _m.toString)();
+// templates
+`${x == null ? void 0 : x.y}`;
+// variables
+var v = x == null ? void 0 : x.y;
+var [v] = x == null ? void 0 : x.y;
+var [v = x == null ? void 0 : x.y] = [1];
+var { v } = x == null ? void 0 : x.y;
+var { v = x == null ? void 0 : x.y } = { v: 1 };
+var { [x == null ? void 0 : x.y]: v } = null;
+// if/else if
+if (x == null ? void 0 : x.y) { }
+if (1) { }
+else if (x == null ? void 0 : x.y) { }
+// switch
+switch (x == null ? void 0 : x.y) {
+}
+switch (1) {
+    case x == null ? void 0 : x.y: break;
+}
+// do/while
+do { } while (x == null ? void 0 : x.y);
+while (x == null ? void 0 : x.y) { }
+// for
+for (x == null ? void 0 : x.y; x == null ? void 0 : x.y; x == null ? void 0 : x.y)
+    ;
+// for..in
+for ({ set value(_a) { x == null ? _a : x.y = _a; } }.value in {})
+    ;
+// for..of
+for ({ set value(_a) { x == null ? _a : x.y = _a; } }.value of [])
+    ;
+// enums
+var E;
+(function (E) {
+    E[E["a"] = x == null ? void 0 : x.y] = "a";
+})(E || (E = {}));
+var _a, _b, _c, _d, _e, _f, _g, _h, _j, _k, _l, _m;
+//// [exportsOk.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.default = x == null ? void 0 : x.y;

tests/baselines/reference/emitter.safeNavigation.es2015.symbols

@@ -0,0 +1,862 @@
+=== tests/cases/conformance/emitter/es2015/safeNavigation/declarations.d.ts ===
+declare var x: any;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+declare var y: any;
+>y : Symbol(y, Decl(declarations.d.ts, 1, 11))
+
+declare var f: ({
+>f : Symbol(f, Decl(declarations.d.ts, 2, 11))
+
+    (): void;
+    <T>(): void;
+>T : Symbol(T, Decl(declarations.d.ts, 4, 5))
+
+    new (): any;
+    new <T>(): any;
+>T : Symbol(T, Decl(declarations.d.ts, 6, 9))
+
+}) | undefined;
+declare var o: { y: typeof f; }
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+>f : Symbol(f, Decl(declarations.d.ts, 2, 11))
+
+declare class Base { x(): any; }
+>Base : Symbol(Base, Decl(declarations.d.ts, 8, 31))
+>x : Symbol(Base.x, Decl(declarations.d.ts, 9, 20))
+
+declare namespace M {
+>M : Symbol(M, Decl(declarations.d.ts, 9, 32))
+
+    export class y {}
+>y : Symbol(y, Decl(declarations.d.ts, 10, 21))
+
+    export class z<T> {}
+>z : Symbol(z, Decl(declarations.d.ts, 11, 21))
+>T : Symbol(T, Decl(declarations.d.ts, 12, 19))
+}
+=== tests/cases/conformance/emitter/es2015/safeNavigation/propertyAccessOk.ts ===
+x.y
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y.z
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x.y?.z
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y?.z
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+=== tests/cases/conformance/emitter/es2015/safeNavigation/elementAccessOk.ts ===
+x["y"]
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"]
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"]["z"]
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x["y"]?.["z"]
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"]?.["z"]
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+=== tests/cases/conformance/emitter/es2015/safeNavigation/callExpressionOk.ts ===
+x()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x.y?.()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x["y"]?.()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+f?.<number>()
+>f : Symbol(f, Decl(declarations.d.ts, 2, 11))
+
+o.y?.<number>()
+>o.y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+o["y"]?.<number>()
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>"y" : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+=== tests/cases/conformance/emitter/es2015/safeNavigation/newExpressionOk.ts ===
+new x()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+new x.y?.()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+new x["y"]?.()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+new f?.<number>()
+>f : Symbol(f, Decl(declarations.d.ts, 2, 11))
+
+new o.y?.<number>()
+>o.y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+new o["y"]?.<number>()
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>"y" : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+=== tests/cases/conformance/emitter/es2015/safeNavigation/mixedOk.ts ===
+x?.y?.["z"]
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"]?.z
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y?.()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+o?.y<number>()
+>o?.y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+o?.y?.<number>()
+>o?.y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+x?.["z"]()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["z"]?.()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+o?.["y"]<number>()
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>"y" : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+o?.["y"]?.<number>()
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>"y" : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+=== tests/cases/conformance/emitter/es2015/safeNavigation/mutationOk.ts ===
+x?.y = 1
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y += 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y -= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y *= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y /= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y %= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y **= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y |= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y &= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y ^= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y <<= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y >>= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y >>>= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y++;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y--;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+++x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+--x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+delete x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] = 1
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] += 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] -= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] *= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] /= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] %= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] **= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] |= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] &= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] ^= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] <<= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] >>= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] >>>= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"]++;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"]--;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+++x?.["y"];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+--x?.["y"];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+delete x?.["y"];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+=== tests/cases/conformance/emitter/es2015/safeNavigation/arrayAssignmentPatternOk.ts ===
+[x?.y] = [1];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+[x?.["y"]] = [1];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+[...x?.y] = [1];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+[...x?.["y"]] = [1];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+=== tests/cases/conformance/emitter/es2015/safeNavigation/objectAssignmentPatternOk.ts ===
+({ a: x?.y } = { a: 1 });
+>a : Symbol(a, Decl(objectAssignmentPatternOk.ts, 0, 2))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(objectAssignmentPatternOk.ts, 0, 16))
+
+({ a: x?.["y"] } = { a: 1 });
+>a : Symbol(a, Decl(objectAssignmentPatternOk.ts, 1, 2))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(objectAssignmentPatternOk.ts, 1, 20))
+
+=== tests/cases/conformance/emitter/es2015/safeNavigation/questionDotDigitIsConditionalOk.ts ===
+x?.3:1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+=== tests/cases/conformance/emitter/es2015/safeNavigation/superPropertyInvocationOk.ts ===
+// supported for invocation of super property
+void class extends Base {
+>Base : Symbol(Base, Decl(declarations.d.ts, 8, 31))
+
+    m() {
+>m : Symbol((Anonymous class).m, Decl(superPropertyInvocationOk.ts, 1, 25))
+
+        super.x?.();
+>super.x : Symbol(Base.x, Decl(declarations.d.ts, 9, 20))
+>super : Symbol(Base, Decl(declarations.d.ts, 8, 31))
+>x : Symbol(Base.x, Decl(declarations.d.ts, 9, 20))
+
+        super["x"]?.();
+>super : Symbol(Base, Decl(declarations.d.ts, 8, 31))
+>"x" : Symbol(Base.x, Decl(declarations.d.ts, 9, 20))
+    }
+}
+
+=== tests/cases/conformance/emitter/es2015/safeNavigation/generalParsingOk.ts ===
+// object literals
+// - computed property names
+void { [x?.y]: 1 }
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void { [x?.["y"]]: 1 }
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void { [x?.()]: 1 }
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void { [new x?.()]: 1 }
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// - property assignments
+void { a: x?.y }
+>a : Symbol(a, Decl(generalParsingOk.ts, 7, 6))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void { a: x?.["y"] }
+>a : Symbol(a, Decl(generalParsingOk.ts, 8, 6))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void { a: x?.() }
+>a : Symbol(a, Decl(generalParsingOk.ts, 9, 6))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void { a: new x?.() }
+>a : Symbol(a, Decl(generalParsingOk.ts, 10, 6))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// classes
+// - computed property names
+// void class { [x?.y] = 1 }        // legal parse, but causes a checker error
+// void class { [x?.["y"]] = 1 }    // legal parse, but causes a checker error
+// void class { [x?.()] = 1 }       // legal parse, but causes a checker error
+// void class { [new f?.()] = 1 }   // legal parse, but causes a checker error
+void class { [Symbol?.toStringTag] = "" }
+>Symbol?.toStringTag : Symbol(SymbolConstructor.toStringTag, Decl(lib.es2015.symbol.wellknown.d.ts, --, --))
+>Symbol : Symbol(Symbol, Decl(lib.es2015.symbol.wellknown.d.ts, --, --), Decl(lib.es2015.symbol.d.ts, --, --), Decl(lib.es2015.symbol.d.ts, --, --))
+>toStringTag : Symbol(SymbolConstructor.toStringTag, Decl(lib.es2015.symbol.wellknown.d.ts, --, --))
+
+// - property declarations
+void class { a = x?.y }
+>a : Symbol((Anonymous class).a, Decl(generalParsingOk.ts, 20, 12))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void class { a = x?.["y"] }
+>a : Symbol((Anonymous class).a, Decl(generalParsingOk.ts, 21, 12))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void class { a = x?.() }
+>a : Symbol((Anonymous class).a, Decl(generalParsingOk.ts, 22, 12))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void class { a = new x?.() }
+>a : Symbol((Anonymous class).a, Decl(generalParsingOk.ts, 23, 12))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// - heritage clauses
+void class extends M?.y {}
+>M?.y : Symbol(M.y, Decl(declarations.d.ts, 10, 21))
+>M : Symbol(M, Decl(declarations.d.ts, 9, 32))
+>y : Symbol(M.y, Decl(declarations.d.ts, 10, 21))
+
+void class extends M?.["y"] {}
+>M : Symbol(M, Decl(declarations.d.ts, 9, 32))
+>"y" : Symbol(M.y, Decl(declarations.d.ts, 10, 21))
+
+void class extends M?.z<number> {}
+>M?.z : Symbol(M.z, Decl(declarations.d.ts, 11, 21))
+>M : Symbol(M, Decl(declarations.d.ts, 9, 32))
+>z : Symbol(M.z, Decl(declarations.d.ts, 11, 21))
+
+// - class decorators
+@x?.y class C1 {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>C1 : Symbol(C1, Decl(generalParsingOk.ts, 27, 34))
+
+@x?.["y"] class C2 {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>C2 : Symbol(C2, Decl(generalParsingOk.ts, 29, 17))
+
+@x?.() class C3 {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>C3 : Symbol(C3, Decl(generalParsingOk.ts, 30, 21))
+
+@new x?.() class C4 {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>C4 : Symbol(C4, Decl(generalParsingOk.ts, 31, 18))
+
+// - member decorators
+class C5 { @x?.y m() {} }
+>C5 : Symbol(C5, Decl(generalParsingOk.ts, 32, 22))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>m : Symbol(C5.m, Decl(generalParsingOk.ts, 34, 10))
+
+class C6 { @x?.["y"] m() {} } // allowed as ?.[ is not ambiguous with computed property names
+>C6 : Symbol(C6, Decl(generalParsingOk.ts, 34, 25))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>m : Symbol(C6.m, Decl(generalParsingOk.ts, 35, 10))
+
+class C7 { @x?.() m() {} }
+>C7 : Symbol(C7, Decl(generalParsingOk.ts, 35, 29))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>m : Symbol(C7.m, Decl(generalParsingOk.ts, 36, 10))
+
+class C8 { @new x?.() m () {} }
+>C8 : Symbol(C8, Decl(generalParsingOk.ts, 36, 26))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>m : Symbol(C8.m, Decl(generalParsingOk.ts, 37, 10))
+
+// - parameter decorators
+class C9 { m(@x?.y a) {} }
+>C9 : Symbol(C9, Decl(generalParsingOk.ts, 37, 31))
+>m : Symbol(C9.m, Decl(generalParsingOk.ts, 39, 10))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 39, 13))
+
+class C10 { m(@x?.["y"] a) {} }
+>C10 : Symbol(C10, Decl(generalParsingOk.ts, 39, 26))
+>m : Symbol(C10.m, Decl(generalParsingOk.ts, 40, 11))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 40, 14))
+
+class C11 { m(@x?.() a) {} }
+>C11 : Symbol(C11, Decl(generalParsingOk.ts, 40, 31))
+>m : Symbol(C11.m, Decl(generalParsingOk.ts, 41, 11))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 41, 14))
+
+class C12 { m(@new x?.() a) {} }
+>C12 : Symbol(C12, Decl(generalParsingOk.ts, 41, 28))
+>m : Symbol(C12.m, Decl(generalParsingOk.ts, 42, 11))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 42, 14))
+
+// functions
+// - parameters
+void function (a = x?.y) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 46, 15))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void function (a = x?.["y"]) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 47, 15))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void function (a = x?.()) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 48, 15))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void function (a = new x?.()) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 49, 15))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// - binding elements
+//   - initializers
+void function ({ a = x?.y }) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 52, 16))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void function ({ a = x?.["y"] }) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 53, 16))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void function ({ a = x?.() }) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 54, 16))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void function ({ a = new x?.() }) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 55, 16))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+//   - computed properties
+void function ({ [x?.y]: a }) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 57, 16))
+
+void function ({ [x?.["y"]]: a }) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 58, 16))
+
+void function ({ [x?.()]: a }) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 59, 16))
+
+void function ({ [new x?.()]: a }) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 60, 16))
+
+// arrow functions
+// - parameters
+((a = x?.y) => {});
+>a : Symbol(a, Decl(generalParsingOk.ts, 64, 2))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+((a = x?.["y"]) => {});
+>a : Symbol(a, Decl(generalParsingOk.ts, 65, 2))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+((a = x?.()) => {});
+>a : Symbol(a, Decl(generalParsingOk.ts, 66, 2))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+((a = new x?.()) => {});
+>a : Symbol(a, Decl(generalParsingOk.ts, 67, 2))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// - expression bodies
+(() => x?.y);
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+(() => x?.["y"]);
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+(() => x?.());
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+(() => new x?.());
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// parenthesis
+(x?.y);
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// comma
+x?.y, f();
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>f : Symbol(f, Decl(declarations.d.ts, 2, 11))
+
+f(), x?.y;
+>f : Symbol(f, Decl(declarations.d.ts, 2, 11))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// conditional
+x?.y ? 0 : 1
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+0 ? x?.y : 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+0 ? 1 : x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// binary
+x?.y + 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y - 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y * 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y / 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y ** 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y % 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y ^ 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y & 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y | 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y << 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y >> 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y >>> 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y && 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y || 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y == 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y === 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y != 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y !== 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y < 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y <= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y > 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y >= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 + x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 - x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 * x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 / x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 ** x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 % x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 ^ x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 & x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 | x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 << x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 >> x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 >>> x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 && x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 || x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 == x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 === x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 != x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 !== x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 < x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 <= x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 > x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 >= x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// prefix unary
++x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+-x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+!x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+~x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// unary
+void x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+typeof x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void function * () { yield x?.y; }
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void async function() { await x?.y; }
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// notnull
+x?.y!.z;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// assertions
+<string>x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y as string;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// array literals
+[x?.y];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+[, x?.y];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+[...x?.y];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// literals
+1?.toString(); // no need for `..`
+>1?.toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+
+1.?.toString();
+>1.?.toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+
+.0?.toString();
+>.0?.toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+
+4e3?.toString();
+>4e3?.toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+
+1.e3?.toString();
+>1.e3?.toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+
+""?.toString();
+>""?.toString : Symbol(String.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(String.toString, Decl(lib.es5.d.ts, --, --))
+
+''?.toString();
+>''?.toString : Symbol(String.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(String.toString, Decl(lib.es5.d.ts, --, --))
+
+``?.toString();
+>``?.toString : Symbol(String.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(String.toString, Decl(lib.es5.d.ts, --, --))
+
+/./?.toString();
+>/./?.toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+
+/./g?.toString();
+>/./g?.toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+
+true?.toString();
+>true?.toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+
+false?.toString();
+>false?.toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+
+// templates
+`${x?.y}`;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// variables
+var v = x?.y;
+>v : Symbol(v, Decl(generalParsingOk.ts, 174, 3), Decl(generalParsingOk.ts, 175, 5), Decl(generalParsingOk.ts, 176, 5), Decl(generalParsingOk.ts, 177, 5), Decl(generalParsingOk.ts, 178, 5), Decl(generalParsingOk.ts, 179, 5))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+var [v] = x?.y;
+>v : Symbol(v, Decl(generalParsingOk.ts, 174, 3), Decl(generalParsingOk.ts, 175, 5), Decl(generalParsingOk.ts, 176, 5), Decl(generalParsingOk.ts, 177, 5), Decl(generalParsingOk.ts, 178, 5), Decl(generalParsingOk.ts, 179, 5))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+var [v = x?.y] = [1];
+>v : Symbol(v, Decl(generalParsingOk.ts, 174, 3), Decl(generalParsingOk.ts, 175, 5), Decl(generalParsingOk.ts, 176, 5), Decl(generalParsingOk.ts, 177, 5), Decl(generalParsingOk.ts, 178, 5), Decl(generalParsingOk.ts, 179, 5))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+var {v} = x?.y;
+>v : Symbol(v, Decl(generalParsingOk.ts, 174, 3), Decl(generalParsingOk.ts, 175, 5), Decl(generalParsingOk.ts, 176, 5), Decl(generalParsingOk.ts, 177, 5), Decl(generalParsingOk.ts, 178, 5), Decl(generalParsingOk.ts, 179, 5))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+var {v = x?.y} = {v:1};
+>v : Symbol(v, Decl(generalParsingOk.ts, 174, 3), Decl(generalParsingOk.ts, 175, 5), Decl(generalParsingOk.ts, 176, 5), Decl(generalParsingOk.ts, 177, 5), Decl(generalParsingOk.ts, 178, 5), Decl(generalParsingOk.ts, 179, 5))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>v : Symbol(v, Decl(generalParsingOk.ts, 178, 18))
+
+var {[x?.y]: v} = null;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>v : Symbol(v, Decl(generalParsingOk.ts, 174, 3), Decl(generalParsingOk.ts, 175, 5), Decl(generalParsingOk.ts, 176, 5), Decl(generalParsingOk.ts, 177, 5), Decl(generalParsingOk.ts, 178, 5), Decl(generalParsingOk.ts, 179, 5))
+
+// if/else if
+if (x?.y) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+if (1) {} else if (x?.y) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// switch
+switch (x?.y) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+switch (1) { case x?.y: break; }
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// do/while
+do {} while (x?.y)
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+while (x?.y) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// for
+for (x?.y; x?.y; x?.y);
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// for..in
+for (x?.y in {});
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// for..of
+for (x?.y of []);
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// enums
+enum E {
+>E : Symbol(E, Decl(generalParsingOk.ts, 200, 17))
+
+    a = x?.y
+>a : Symbol(E.a, Decl(generalParsingOk.ts, 203, 8))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+}
+
+=== tests/cases/conformance/emitter/es2015/safeNavigation/exportsOk.ts ===
+export default x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+

tests/baselines/reference/emitter.safeNavigation.es3.js

@@ -0,0 +1,876 @@
+//// [tests/cases/conformance/emitter/es3/safeNavigation/emitter.safeNavigation.es3.ts] ////
+
+//// [declarations.d.ts]
+declare var x: any;
+declare var y: any;
+declare var f: ({
+    (): void;
+    <T>(): void;
+    new (): any;
+    new <T>(): any;
+}) | undefined;
+declare var o: { y: typeof f; }
+declare class Base { x(): any; }
+declare namespace M {
+    export class y {}
+    export class z<T> {}
+}
+//// [propertyAccessOk.ts]
+x.y
+x?.y
+x?.y.z
+x.y?.z
+x?.y?.z
+//// [elementAccessOk.ts]
+x["y"]
+x?.["y"]
+x?.["y"]["z"]
+x["y"]?.["z"]
+x?.["y"]?.["z"]
+//// [callExpressionOk.ts]
+x()
+x?.()
+x.y?.()
+x["y"]?.()
+f?.<number>()
+o.y?.<number>()
+o["y"]?.<number>()
+//// [newExpressionOk.ts]
+new x()
+new x.y?.()
+new x["y"]?.()
+new f?.<number>()
+new o.y?.<number>()
+new o["y"]?.<number>()
+//// [mixedOk.ts]
+x?.y?.["z"]
+x?.["y"]?.z
+x?.y()
+x?.y?.()
+o?.y<number>()
+o?.y?.<number>()
+x?.["z"]()
+x?.["z"]?.()
+o?.["y"]<number>()
+o?.["y"]?.<number>()
+//// [mutationOk.ts]
+x?.y = 1
+x?.y += 1;
+x?.y -= 1;
+x?.y *= 1;
+x?.y /= 1;
+x?.y %= 1;
+x?.y **= 1;
+x?.y |= 1;
+x?.y &= 1;
+x?.y ^= 1;
+x?.y <<= 1;
+x?.y >>= 1;
+x?.y >>>= 1;
+x?.y++;
+x?.y--;
+++x?.y;
+--x?.y;
+delete x?.y;
+x?.["y"] = 1
+x?.["y"] += 1;
+x?.["y"] -= 1;
+x?.["y"] *= 1;
+x?.["y"] /= 1;
+x?.["y"] %= 1;
+x?.["y"] **= 1;
+x?.["y"] |= 1;
+x?.["y"] &= 1;
+x?.["y"] ^= 1;
+x?.["y"] <<= 1;
+x?.["y"] >>= 1;
+x?.["y"] >>>= 1;
+x?.["y"]++;
+x?.["y"]--;
+++x?.["y"];
+--x?.["y"];
+delete x?.["y"];
+//// [arrayAssignmentPatternOk.ts]
+[x?.y] = [1];
+[x?.["y"]] = [1];
+[...x?.y] = [1];
+[...x?.["y"]] = [1];
+//// [objectAssignmentPatternOk.ts]
+({ a: x?.y } = { a: 1 });
+({ a: x?.["y"] } = { a: 1 });
+//// [questionDotDigitIsConditionalOk.ts]
+x?.3:1;
+//// [superPropertyInvocationOk.ts]
+// supported for invocation of super property
+void class extends Base {
+    m() {
+        super.x?.();
+    }
+}
+
+//// [generalParsingOk.ts]
+// object literals
+// - computed property names
+void { [x?.y]: 1 }
+void { [x?.["y"]]: 1 }
+void { [x?.()]: 1 }
+void { [new x?.()]: 1 }
+// - property assignments
+void { a: x?.y }
+void { a: x?.["y"] }
+void { a: x?.() }
+void { a: new x?.() }
+
+// classes
+// - computed property names
+// void class { [x?.y] = 1 }        // legal parse, but causes a checker error
+// void class { [x?.["y"]] = 1 }    // legal parse, but causes a checker error
+// void class { [x?.()] = 1 }       // legal parse, but causes a checker error
+// void class { [new f?.()] = 1 }   // legal parse, but causes a checker error
+void class { [Symbol?.toStringTag] = "" }
+// - property declarations
+void class { a = x?.y }
+void class { a = x?.["y"] }
+void class { a = x?.() }
+void class { a = new x?.() }
+// - heritage clauses
+void class extends M?.y {}
+void class extends M?.["y"] {}
+void class extends M?.z<number> {}
+// - class decorators
+@x?.y class C1 {}
+@x?.["y"] class C2 {}
+@x?.() class C3 {}
+@new x?.() class C4 {}
+// - member decorators
+class C5 { @x?.y m() {} }
+class C6 { @x?.["y"] m() {} } // allowed as ?.[ is not ambiguous with computed property names
+class C7 { @x?.() m() {} }
+class C8 { @new x?.() m () {} }
+// - parameter decorators
+class C9 { m(@x?.y a) {} }
+class C10 { m(@x?.["y"] a) {} }
+class C11 { m(@x?.() a) {} }
+class C12 { m(@new x?.() a) {} }
+
+// functions
+// - parameters
+void function (a = x?.y) {}
+void function (a = x?.["y"]) {}
+void function (a = x?.()) {}
+void function (a = new x?.()) {}
+// - binding elements
+//   - initializers
+void function ({ a = x?.y }) {}
+void function ({ a = x?.["y"] }) {}
+void function ({ a = x?.() }) {}
+void function ({ a = new x?.() }) {}
+//   - computed properties
+void function ({ [x?.y]: a }) {}
+void function ({ [x?.["y"]]: a }) {}
+void function ({ [x?.()]: a }) {}
+void function ({ [new x?.()]: a }) {}
+
+// arrow functions
+// - parameters
+((a = x?.y) => {});
+((a = x?.["y"]) => {});
+((a = x?.()) => {});
+((a = new x?.()) => {});
+// - expression bodies
+(() => x?.y);
+(() => x?.["y"]);
+(() => x?.());
+(() => new x?.());
+
+// parenthesis
+(x?.y);
+
+// comma
+x?.y, f();
+f(), x?.y;
+
+// conditional
+x?.y ? 0 : 1
+0 ? x?.y : 1;
+0 ? 1 : x?.y;
+
+// binary
+x?.y + 1;
+x?.y - 1;
+x?.y * 1;
+x?.y / 1;
+x?.y ** 1;
+x?.y % 1;
+x?.y ^ 1;
+x?.y & 1;
+x?.y | 1;
+x?.y << 1;
+x?.y >> 1;
+x?.y >>> 1;
+x?.y && 1;
+x?.y || 1;
+x?.y == 1;
+x?.y === 1;
+x?.y != 1;
+x?.y !== 1;
+x?.y < 1;
+x?.y <= 1;
+x?.y > 1;
+x?.y >= 1;
+1 + x?.y;
+1 - x?.y;
+1 * x?.y;
+1 / x?.y;
+1 ** x?.y;
+1 % x?.y;
+1 ^ x?.y;
+1 & x?.y;
+1 | x?.y;
+1 << x?.y;
+1 >> x?.y;
+1 >>> x?.y;
+1 && x?.y;
+1 || x?.y;
+1 == x?.y;
+1 === x?.y;
+1 != x?.y;
+1 !== x?.y;
+1 < x?.y;
+1 <= x?.y;
+1 > x?.y;
+1 >= x?.y;
+
+// prefix unary
++x?.y;
+-x?.y;
+!x?.y;
+~x?.y;
+
+// unary
+void x?.y;
+typeof x?.y;
+void function * () { yield x?.y; }
+void async function() { await x?.y; }
+
+// notnull
+x?.y!.z;
+
+// assertions
+<string>x?.y;
+x?.y as string;
+
+// array literals
+[x?.y];
+[, x?.y];
+[...x?.y];
+
+// literals
+1?.toString(); // no need for `..`
+1.?.toString();
+.0?.toString();
+4e3?.toString();
+1.e3?.toString();
+""?.toString();
+''?.toString();
+``?.toString();
+/./?.toString();
+/./g?.toString();
+true?.toString();
+false?.toString();
+
+// templates
+`${x?.y}`;
+
+// variables
+var v = x?.y;
+var [v] = x?.y;
+var [v = x?.y] = [1];
+var {v} = x?.y;
+var {v = x?.y} = {v:1};
+var {[x?.y]: v} = null;
+
+// if/else if
+if (x?.y) {}
+if (1) {} else if (x?.y) {}
+
+// switch
+switch (x?.y) {}
+switch (1) { case x?.y: break; }
+
+// do/while
+do {} while (x?.y)
+while (x?.y) {}
+
+// for
+for (x?.y; x?.y; x?.y);
+
+// for..in
+for (x?.y in {});
+
+// for..of
+for (x?.y of []);
+
+// enums
+enum E {
+    a = x?.y
+}
+
+//// [exportsOk.ts]
+export default x?.y;
+
+//// [propertyAccessOk.js]
+x.y;
+x == null ? void 0 : x.y;
+(x == null ? void 0 : x.y).z;
+(_a = x.y) == null ? void 0 : _a.z;
+(_b = x == null ? void 0 : x.y) == null ? void 0 : _b.z;
+var _a, _b;
+//// [elementAccessOk.js]
+x["y"];
+x == null ? void 0 : x["y"];
+(x == null ? void 0 : x["y"])["z"];
+(_a = x["y"]) == null ? void 0 : _a["z"];
+(_b = x == null ? void 0 : x["y"]) == null ? void 0 : _b["z"];
+var _a, _b;
+//// [callExpressionOk.js]
+x();
+x == null ? void 0 : x();
+(_a = x.y) == null ? void 0 : _a.call(x);
+(_b = x["y"]) == null ? void 0 : _b.call(x);
+f == null ? void 0 : f();
+(_c = o.y) == null ? void 0 : _c.call(o);
+(_d = o["y"]) == null ? void 0 : _d.call(o);
+var _a, _b, _c, _d;
+//// [newExpressionOk.js]
+new x();
+(_a = x.y) == null ? void 0 : new _a();
+(_b = x["y"]) == null ? void 0 : new _b();
+f == null ? void 0 : new f();
+(_c = o.y) == null ? void 0 : new _c();
+(_d = o["y"]) == null ? void 0 : new _d();
+var _a, _b, _c, _d;
+//// [mixedOk.js]
+(_a = x == null ? void 0 : x.y) == null ? void 0 : _a["z"];
+(_b = x == null ? void 0 : x["y"]) == null ? void 0 : _b.z;
+(x == null ? void 0 : x.y)();
+(_c = x == null ? void 0 : x.y) == null ? void 0 : _c.call(x);
+(o == null ? void 0 : o.y)();
+(_d = o == null ? void 0 : o.y) == null ? void 0 : _d.call(o);
+(x == null ? void 0 : x["z"])();
+(_e = x == null ? void 0 : x["z"]) == null ? void 0 : _e.call(x);
+(o == null ? void 0 : o["y"])();
+(_f = o == null ? void 0 : o["y"]) == null ? void 0 : _f.call(o);
+var _a, _b, _c, _d, _e, _f;
+//// [mutationOk.js]
+_a = 1, x == null ? _a : x.y = _a;
+_b = 1, x == null ? _b : x.y += _b;
+_c = 1, x == null ? _c : x.y -= _c;
+_d = 1, x == null ? _d : x.y *= _d;
+_e = 1, x == null ? _e : x.y /= _e;
+_f = 1, x == null ? _f : x.y %= _f;
+_g = 1, x == null ? _g : (_h = x).y = Math.pow(_h.y, _g);
+_j = 1, x == null ? _j : x.y |= _j;
+_k = 1, x == null ? _k : x.y &= _k;
+_l = 1, x == null ? _l : x.y ^= _l;
+_m = 1, x == null ? _m : x.y <<= _m;
+_o = 1, x == null ? _o : x.y >>= _o;
+_p = 1, x == null ? _p : x.y >>>= _p;
+x == null ? void 0 : x.y++;
+x == null ? void 0 : x.y--;
+x == null ? void 0 : ++x.y;
+x == null ? void 0 : --x.y;
+x == null ? true : delete x.y;
+_q = 1, x == null ? _q : x["y"] = _q;
+_r = 1, x == null ? _r : x["y"] += _r;
+_s = 1, x == null ? _s : x["y"] -= _s;
+_t = 1, x == null ? _t : x["y"] *= _t;
+_u = 1, x == null ? _u : x["y"] /= _u;
+_v = 1, x == null ? _v : x["y"] %= _v;
+_w = 1, x == null ? _w : (_x = x)[_y = "y"] = Math.pow(_x[_y], _w);
+_z = 1, x == null ? _z : x["y"] |= _z;
+_0 = 1, x == null ? _0 : x["y"] &= _0;
+_1 = 1, x == null ? _1 : x["y"] ^= _1;
+_2 = 1, x == null ? _2 : x["y"] <<= _2;
+_3 = 1, x == null ? _3 : x["y"] >>= _3;
+_4 = 1, x == null ? _4 : x["y"] >>>= _4;
+x == null ? void 0 : x["y"]++;
+x == null ? void 0 : x["y"]--;
+x == null ? void 0 : ++x["y"];
+x == null ? void 0 : --x["y"];
+x == null ? true : delete x["y"];
+var _a, _b, _c, _d, _e, _f, _g, _j, _k, _l, _m, _o, _p, _q, _r, _s, _t, _u, _v, _w, _z, _0, _1, _2, _3, _4;
+var _h, _x, _y;
+//// [arrayAssignmentPatternOk.js]
+_a = [1], (x == null ? void 0 : x.y = _a[0], _a);
+_b = [1], (x == null ? void 0 : x["y"] = _b[0], _b);
+_c = [1], (x == null ? void 0 : x.y = _c.slice(0), _c);
+_d = [1], (x == null ? void 0 : x["y"] = _d.slice(0), _d);
+var _a, _b, _c, _d;
+//// [objectAssignmentPatternOk.js]
+(_a = { a: 1 }, (x == null ? void 0 : x.y = _a.a, _a));
+(_b = { a: 1 }, (x == null ? void 0 : x["y"] = _b.a, _b));
+var _a, _b;
+//// [questionDotDigitIsConditionalOk.js]
+x ? .3 : 1;
+//// [superPropertyInvocationOk.js]
+var __extends = (this && this.__extends) || (function () {
+    var extendStatics = Object.setPrototypeOf ||
+        ({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) ||
+        function (d, b) { for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p]; };
+    return function (d, b) {
+        extendStatics(d, b);
+        function __() { this.constructor = d; }
+        d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
+    };
+})();
+// supported for invocation of super property
+void (function (_super) {
+    __extends(class_1, _super);
+    function class_1() {
+        return _super !== null && _super.apply(this, arguments) || this;
+    }
+    class_1.prototype.m = function () {
+        (_a = _super.prototype.x) == null ? void 0 : _a.call(this);
+        var _a;
+    };
+    return class_1;
+}(Base));
+//// [generalParsingOk.js]
+var __extends = (this && this.__extends) || (function () {
+    var extendStatics = Object.setPrototypeOf ||
+        ({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) ||
+        function (d, b) { for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p]; };
+    return function (d, b) {
+        extendStatics(d, b);
+        function __() { this.constructor = d; }
+        d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
+    };
+})();
+var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
+    var c = arguments.length, r = c < 3 ? target : desc === null ? desc = Object.getOwnPropertyDescriptor(target, key) : desc, d;
+    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") r = Reflect.decorate(decorators, target, key, desc);
+    else for (var i = decorators.length - 1; i >= 0; i--) if (d = decorators[i]) r = (c < 3 ? d(r) : c > 3 ? d(target, key, r) : d(target, key)) || r;
+    return c > 3 && r && Object.defineProperty(target, key, r), r;
+};
+var __param = (this && this.__param) || function (paramIndex, decorator) {
+    return function (target, key) { decorator(target, key, paramIndex); }
+};
+var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    return new (P || (P = Promise))(function (resolve, reject) {
+        function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
+        function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
+        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        step((generator = generator.apply(thisArg, _arguments || [])).next());
+    });
+};
+var __generator = (this && this.__generator) || function (thisArg, body) {
+    var _ = { label: 0, sent: function() { if (t[0] & 1) throw t[1]; return t[1]; }, trys: [], ops: [] }, f, y, t, g;
+    return g = { next: verb(0), "throw": verb(1), "return": verb(2) }, typeof Symbol === "function" && (g[Symbol.iterator] = function() { return this; }), g;
+    function verb(n) { return function (v) { return step([n, v]); }; }
+    function step(op) {
+        if (f) throw new TypeError("Generator is already executing.");
+        while (_) try {
+            if (f = 1, y && (t = y[op[0] & 2 ? "return" : op[0] ? "throw" : "next"]) && !(t = t.call(y, op[1])).done) return t;
+            if (y = 0, t) op = [0, t.value];
+            switch (op[0]) {
+                case 0: case 1: t = op; break;
+                case 4: _.label++; return { value: op[1], done: false };
+                case 5: _.label++; y = op[1]; op = [0]; continue;
+                case 7: op = _.ops.pop(); _.trys.pop(); continue;
+                default:
+                    if (!(t = _.trys, t = t.length > 0 && t[t.length - 1]) && (op[0] === 6 || op[0] === 2)) { _ = 0; continue; }
+                    if (op[0] === 3 && (!t || (op[1] > t[0] && op[1] < t[3]))) { _.label = op[1]; break; }
+                    if (op[0] === 6 && _.label < t[1]) { _.label = t[1]; t = op; break; }
+                    if (t && _.label < t[2]) { _.label = t[2]; _.ops.push(op); break; }
+                    if (t[2]) _.ops.pop();
+                    _.trys.pop(); continue;
+            }
+            op = body.call(thisArg, _);
+        } catch (e) { op = [6, e]; y = 0; } finally { f = t = 0; }
+        if (op[0] & 5) throw op[1]; return { value: op[0] ? op[1] : void 0, done: true };
+    }
+};
+// object literals
+// - computed property names
+void (_a = {}, _a[x == null ? void 0 : x.y] = 1, _a);
+void (_b = {}, _b[x == null ? void 0 : x["y"]] = 1, _b);
+void (_c = {}, _c[x == null ? void 0 : x()] = 1, _c);
+void (_d = {}, _d[x == null ? void 0 : new x()] = 1, _d);
+// - property assignments
+void { a: x == null ? void 0 : x.y };
+void { a: x == null ? void 0 : x["y"] };
+void { a: x == null ? void 0 : x() };
+void { a: x == null ? void 0 : new x() };
+// classes
+// - computed property names
+// void class { [x?.y] = 1 }        // legal parse, but causes a checker error
+// void class { [x?.["y"]] = 1 }    // legal parse, but causes a checker error
+// void class { [x?.()] = 1 }       // legal parse, but causes a checker error
+// void class { [new f?.()] = 1 }   // legal parse, but causes a checker error
+void (function () {
+    function class_1() {
+        this[Symbol == null ? void 0 : Symbol.toStringTag] = "";
+    }
+    return class_1;
+}());
+// - property declarations
+void (function () {
+    function class_2() {
+        this.a = x == null ? void 0 : x.y;
+    }
+    return class_2;
+}());
+void (function () {
+    function class_3() {
+        this.a = x == null ? void 0 : x["y"];
+    }
+    return class_3;
+}());
+void (function () {
+    function class_4() {
+        this.a = x == null ? void 0 : x();
+    }
+    return class_4;
+}());
+void (function () {
+    function class_5() {
+        this.a = x == null ? void 0 : new x();
+    }
+    return class_5;
+}());
+// - heritage clauses
+void (function (_super) {
+    __extends(class_6, _super);
+    function class_6() {
+        return _super !== null && _super.apply(this, arguments) || this;
+    }
+    return class_6;
+}((M == null ? void 0 : M.y)));
+void (function (_super) {
+    __extends(class_7, _super);
+    function class_7() {
+        return _super !== null && _super.apply(this, arguments) || this;
+    }
+    return class_7;
+}((M == null ? void 0 : M["y"])));
+void (function (_super) {
+    __extends(class_8, _super);
+    function class_8() {
+        return _super !== null && _super.apply(this, arguments) || this;
+    }
+    return class_8;
+}((M == null ? void 0 : M.z)));
+// - class decorators
+var C1 = (function () {
+    function C1() {
+    }
+    return C1;
+}());
+C1 = __decorate([
+    x == null ? void 0 : x.y
+], C1);
+var C2 = (function () {
+    function C2() {
+    }
+    return C2;
+}());
+C2 = __decorate([
+    x == null ? void 0 : x["y"]
+], C2);
+var C3 = (function () {
+    function C3() {
+    }
+    return C3;
+}());
+C3 = __decorate([
+    x == null ? void 0 : x()
+], C3);
+var C4 = (function () {
+    function C4() {
+    }
+    return C4;
+}());
+C4 = __decorate([
+    x == null ? void 0 : new x()
+], C4);
+// - member decorators
+var C5 = (function () {
+    function C5() {
+    }
+    C5.prototype.m = function () { };
+    return C5;
+}());
+__decorate([
+    x == null ? void 0 : x.y
+], C5.prototype, "m");
+var C6 = (function () {
+    function C6() {
+    }
+    C6.prototype.m = function () { };
+    return C6;
+}()); // allowed as ?.[ is not ambiguous with computed property names
+__decorate([
+    x == null ? void 0 : x["y"]
+], C6.prototype, "m");
+var C7 = (function () {
+    function C7() {
+    }
+    C7.prototype.m = function () { };
+    return C7;
+}());
+__decorate([
+    x == null ? void 0 : x()
+], C7.prototype, "m");
+var C8 = (function () {
+    function C8() {
+    }
+    C8.prototype.m = function () { };
+    return C8;
+}());
+__decorate([
+    x == null ? void 0 : new x()
+], C8.prototype, "m");
+// - parameter decorators
+var C9 = (function () {
+    function C9() {
+    }
+    C9.prototype.m = function (a) { };
+    return C9;
+}());
+__decorate([
+    __param(0, x == null ? void 0 : x.y)
+], C9.prototype, "m");
+var C10 = (function () {
+    function C10() {
+    }
+    C10.prototype.m = function (a) { };
+    return C10;
+}());
+__decorate([
+    __param(0, x == null ? void 0 : x["y"])
+], C10.prototype, "m");
+var C11 = (function () {
+    function C11() {
+    }
+    C11.prototype.m = function (a) { };
+    return C11;
+}());
+__decorate([
+    __param(0, x == null ? void 0 : x())
+], C11.prototype, "m");
+var C12 = (function () {
+    function C12() {
+    }
+    C12.prototype.m = function (a) { };
+    return C12;
+}());
+__decorate([
+    __param(0, x == null ? void 0 : new x())
+], C12.prototype, "m");
+// functions
+// - parameters
+void function (a) {
+    if (a === void 0) { a = x == null ? void 0 : x.y; }
+};
+void function (a) {
+    if (a === void 0) { a = x == null ? void 0 : x["y"]; }
+};
+void function (a) {
+    if (a === void 0) { a = x == null ? void 0 : x(); }
+};
+void function (a) {
+    if (a === void 0) { a = x == null ? void 0 : new x(); }
+};
+// - binding elements
+//   - initializers
+void function (_a) {
+    var _b = _a.a, a = _b === void 0 ? x == null ? void 0 : x.y : _b;
+};
+void function (_a) {
+    var _b = _a.a, a = _b === void 0 ? x == null ? void 0 : x["y"] : _b;
+};
+void function (_a) {
+    var _b = _a.a, a = _b === void 0 ? x == null ? void 0 : x() : _b;
+};
+void function (_a) {
+    var _b = _a.a, a = _b === void 0 ? x == null ? void 0 : new x() : _b;
+};
+//   - computed properties
+void function (_a) {
+    var _b = x == null ? void 0 : x.y, a = _a[_b];
+};
+void function (_a) {
+    var _b = x == null ? void 0 : x["y"], a = _a[_b];
+};
+void function (_a) {
+    var _b = x == null ? void 0 : x(), a = _a[_b];
+};
+void function (_a) {
+    var _b = x == null ? void 0 : new x(), a = _a[_b];
+}(function (a) {
+    if (a === void 0) { a = x == null ? void 0 : x.y; }
+});
+(function (a) {
+    if (a === void 0) { a = x == null ? void 0 : x["y"]; }
+});
+(function (a) {
+    if (a === void 0) { a = x == null ? void 0 : x(); }
+});
+(function (a) {
+    if (a === void 0) { a = x == null ? void 0 : new x(); }
+});
+// - expression bodies
+(function () { return x == null ? void 0 : x.y; });
+(function () { return x == null ? void 0 : x["y"]; });
+(function () { return x == null ? void 0 : x(); });
+(function () { return x == null ? void 0 : new x(); });
+// parenthesis
+(x == null ? void 0 : x.y);
+// comma
+x == null ? void 0 : x.y, f();
+f(), x == null ? void 0 : x.y;
+// conditional
+x == null ? void 0 : x.y ? 0 : 1;
+0 ? x == null ? void 0 : x.y : 1;
+0 ? 1 : x == null ? void 0 : x.y;
+// binary
+(x == null ? void 0 : x.y) + 1;
+(x == null ? void 0 : x.y) - 1;
+(x == null ? void 0 : x.y) * 1;
+(x == null ? void 0 : x.y) / 1;
+Math.pow((x == null ? void 0 : x.y), 1);
+(x == null ? void 0 : x.y) % 1;
+(x == null ? void 0 : x.y) ^ 1;
+(x == null ? void 0 : x.y) & 1;
+(x == null ? void 0 : x.y) | 1;
+(x == null ? void 0 : x.y) << 1;
+(x == null ? void 0 : x.y) >> 1;
+(x == null ? void 0 : x.y) >>> 1;
+(x == null ? void 0 : x.y) && 1;
+(x == null ? void 0 : x.y) || 1;
+(x == null ? void 0 : x.y) == 1;
+(x == null ? void 0 : x.y) === 1;
+(x == null ? void 0 : x.y) != 1;
+(x == null ? void 0 : x.y) !== 1;
+(x == null ? void 0 : x.y) < 1;
+(x == null ? void 0 : x.y) <= 1;
+(x == null ? void 0 : x.y) > 1;
+(x == null ? void 0 : x.y) >= 1;
+1 + (x == null ? void 0 : x.y);
+1 - (x == null ? void 0 : x.y);
+1 * (x == null ? void 0 : x.y);
+1 / (x == null ? void 0 : x.y);
+Math.pow(1, (x == null ? void 0 : x.y));
+1 % (x == null ? void 0 : x.y);
+1 ^ (x == null ? void 0 : x.y);
+1 & (x == null ? void 0 : x.y);
+1 | (x == null ? void 0 : x.y);
+1 << (x == null ? void 0 : x.y);
+1 >> (x == null ? void 0 : x.y);
+1 >>> (x == null ? void 0 : x.y);
+1 && (x == null ? void 0 : x.y);
+1 || (x == null ? void 0 : x.y);
+1 == (x == null ? void 0 : x.y);
+1 === (x == null ? void 0 : x.y);
+1 != (x == null ? void 0 : x.y);
+1 !== (x == null ? void 0 : x.y);
+1 < (x == null ? void 0 : x.y);
+1 <= (x == null ? void 0 : x.y);
+1 > (x == null ? void 0 : x.y);
+1 >= (x == null ? void 0 : x.y);
+// prefix unary
++(x == null ? void 0 : x.y);
+-(x == null ? void 0 : x.y);
+!(x == null ? void 0 : x.y);
+~(x == null ? void 0 : x.y);
+// unary
+void (x == null ? void 0 : x.y);
+typeof (x == null ? void 0 : x.y);
+void function () { return __generator(this, function (_a) {
+    switch (_a.label) {
+        case 0: return [4 /*yield*/, x == null ? void 0 : x.y];
+        case 1:
+            _a.sent();
+            return [2 /*return*/];
+    }
+}); };
+void function () {
+    return __awaiter(this, void 0, void 0, function () { return __generator(this, function (_a) {
+        switch (_a.label) {
+            case 0: return [4 /*yield*/, (x == null ? void 0 : x.y)];
+            case 1:
+                _a.sent();
+                return [2 /*return*/];
+        }
+    }); });
+};
+// notnull
+(x == null ? void 0 : x.y).z;
+// assertions
+x == null ? void 0 : x.y;
+x == null ? void 0 : x.y;
+// array literals
+[x == null ? void 0 : x.y];
+[, x == null ? void 0 : x.y];
+(x == null ? void 0 : x.y).slice();
+// literals
+((_e = 1) == null ? void 0 : _e.toString)(); // no need for `..`
+((_f = 1.) == null ? void 0 : _f.toString)();
+((_g = .0) == null ? void 0 : _g.toString)();
+((_h = 4e3) == null ? void 0 : _h.toString)();
+((_j = 1.e3) == null ? void 0 : _j.toString)();
+((_k = "") == null ? void 0 : _k.toString)();
+((_l = '') == null ? void 0 : _l.toString)();
+((_m = "") == null ? void 0 : _m.toString)();
+((_o = /./) == null ? void 0 : _o.toString)();
+((_p = /./g) == null ? void 0 : _p.toString)();
+((_q = true) == null ? void 0 : _q.toString)();
+((_r = false) == null ? void 0 : _r.toString)();
+// templates
+"" + (x == null ? void 0 : x.y);
+// variables
+var v = x == null ? void 0 : x.y;
+var v = (x == null ? void 0 : x.y)[0];
+var _s = [1][0], v = _s === void 0 ? x == null ? void 0 : x.y : _s;
+var v = (x == null ? void 0 : x.y).v;
+var _t = { v: 1 }.v, v = _t === void 0 ? x == null ? void 0 : x.y : _t;
+var _u = x == null ? void 0 : x.y, v = null[_u];
+// if/else if
+if (x == null ? void 0 : x.y) { }
+if (1) { }
+else if (x == null ? void 0 : x.y) { }
+// switch
+switch (x == null ? void 0 : x.y) {
+}
+switch (1) {
+    case x == null ? void 0 : x.y: break;
+}
+// do/while
+do { } while (x == null ? void 0 : x.y);
+while (x == null ? void 0 : x.y) { }
+// for
+for (x == null ? void 0 : x.y; x == null ? void 0 : x.y; x == null ? void 0 : x.y)
+    ;
+// for..in
+for (var _v in {}) {
+    x == null ? _v : x.y = _v;
+    ;
+}
+// for..of
+for (var _i = 0, _w = []; _i < _w.length; _i++) {
+    var _x = _w[_i];
+    x == null ? _x : x.y = _x;
+    ;
+}
+// enums
+var E;
+(function (E) {
+    E[E["a"] = x == null ? void 0 : x.y] = "a";
+})(E || (E = {}));
+var _e, _f, _g, _h, _j, _k, _l, _m, _o, _p, _q, _r, _v, _x;
+var _a, _b, _c, _d;
+//// [exportsOk.js]
+"use strict";
+exports.__esModule = true;
+exports["default"] = x == null ? void 0 : x.y;

tests/baselines/reference/emitter.safeNavigation.es3.symbols

@@ -0,0 +1,858 @@
+=== tests/cases/conformance/emitter/es3/safeNavigation/declarations.d.ts ===
+declare var x: any;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+declare var y: any;
+>y : Symbol(y, Decl(declarations.d.ts, 1, 11))
+
+declare var f: ({
+>f : Symbol(f, Decl(declarations.d.ts, 2, 11))
+
+    (): void;
+    <T>(): void;
+>T : Symbol(T, Decl(declarations.d.ts, 4, 5))
+
+    new (): any;
+    new <T>(): any;
+>T : Symbol(T, Decl(declarations.d.ts, 6, 9))
+
+}) | undefined;
+declare var o: { y: typeof f; }
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+>f : Symbol(f, Decl(declarations.d.ts, 2, 11))
+
+declare class Base { x(): any; }
+>Base : Symbol(Base, Decl(declarations.d.ts, 8, 31))
+>x : Symbol(Base.x, Decl(declarations.d.ts, 9, 20))
+
+declare namespace M {
+>M : Symbol(M, Decl(declarations.d.ts, 9, 32))
+
+    export class y {}
+>y : Symbol(y, Decl(declarations.d.ts, 10, 21))
+
+    export class z<T> {}
+>z : Symbol(z, Decl(declarations.d.ts, 11, 21))
+>T : Symbol(T, Decl(declarations.d.ts, 12, 19))
+}
+=== tests/cases/conformance/emitter/es3/safeNavigation/propertyAccessOk.ts ===
+x.y
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y.z
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x.y?.z
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y?.z
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+=== tests/cases/conformance/emitter/es3/safeNavigation/elementAccessOk.ts ===
+x["y"]
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"]
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"]["z"]
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x["y"]?.["z"]
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"]?.["z"]
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+=== tests/cases/conformance/emitter/es3/safeNavigation/callExpressionOk.ts ===
+x()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x.y?.()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x["y"]?.()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+f?.<number>()
+>f : Symbol(f, Decl(declarations.d.ts, 2, 11))
+
+o.y?.<number>()
+>o.y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+o["y"]?.<number>()
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>"y" : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+=== tests/cases/conformance/emitter/es3/safeNavigation/newExpressionOk.ts ===
+new x()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+new x.y?.()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+new x["y"]?.()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+new f?.<number>()
+>f : Symbol(f, Decl(declarations.d.ts, 2, 11))
+
+new o.y?.<number>()
+>o.y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+new o["y"]?.<number>()
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>"y" : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+=== tests/cases/conformance/emitter/es3/safeNavigation/mixedOk.ts ===
+x?.y?.["z"]
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"]?.z
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y?.()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+o?.y<number>()
+>o?.y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+o?.y?.<number>()
+>o?.y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+x?.["z"]()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["z"]?.()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+o?.["y"]<number>()
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>"y" : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+o?.["y"]?.<number>()
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>"y" : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+=== tests/cases/conformance/emitter/es3/safeNavigation/mutationOk.ts ===
+x?.y = 1
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y += 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y -= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y *= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y /= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y %= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y **= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y |= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y &= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y ^= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y <<= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y >>= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y >>>= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y++;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y--;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+++x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+--x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+delete x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] = 1
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] += 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] -= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] *= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] /= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] %= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] **= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] |= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] &= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] ^= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] <<= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] >>= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] >>>= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"]++;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"]--;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+++x?.["y"];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+--x?.["y"];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+delete x?.["y"];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+=== tests/cases/conformance/emitter/es3/safeNavigation/arrayAssignmentPatternOk.ts ===
+[x?.y] = [1];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+[x?.["y"]] = [1];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+[...x?.y] = [1];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+[...x?.["y"]] = [1];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+=== tests/cases/conformance/emitter/es3/safeNavigation/objectAssignmentPatternOk.ts ===
+({ a: x?.y } = { a: 1 });
+>a : Symbol(a, Decl(objectAssignmentPatternOk.ts, 0, 2))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(objectAssignmentPatternOk.ts, 0, 16))
+
+({ a: x?.["y"] } = { a: 1 });
+>a : Symbol(a, Decl(objectAssignmentPatternOk.ts, 1, 2))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(objectAssignmentPatternOk.ts, 1, 20))
+
+=== tests/cases/conformance/emitter/es3/safeNavigation/questionDotDigitIsConditionalOk.ts ===
+x?.3:1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+=== tests/cases/conformance/emitter/es3/safeNavigation/superPropertyInvocationOk.ts ===
+// supported for invocation of super property
+void class extends Base {
+>Base : Symbol(Base, Decl(declarations.d.ts, 8, 31))
+
+    m() {
+>m : Symbol((Anonymous class).m, Decl(superPropertyInvocationOk.ts, 1, 25))
+
+        super.x?.();
+>super.x : Symbol(Base.x, Decl(declarations.d.ts, 9, 20))
+>super : Symbol(Base, Decl(declarations.d.ts, 8, 31))
+>x : Symbol(Base.x, Decl(declarations.d.ts, 9, 20))
+    }
+}
+
+=== tests/cases/conformance/emitter/es3/safeNavigation/generalParsingOk.ts ===
+// object literals
+// - computed property names
+void { [x?.y]: 1 }
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void { [x?.["y"]]: 1 }
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void { [x?.()]: 1 }
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void { [new x?.()]: 1 }
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// - property assignments
+void { a: x?.y }
+>a : Symbol(a, Decl(generalParsingOk.ts, 7, 6))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void { a: x?.["y"] }
+>a : Symbol(a, Decl(generalParsingOk.ts, 8, 6))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void { a: x?.() }
+>a : Symbol(a, Decl(generalParsingOk.ts, 9, 6))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void { a: new x?.() }
+>a : Symbol(a, Decl(generalParsingOk.ts, 10, 6))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// classes
+// - computed property names
+// void class { [x?.y] = 1 }        // legal parse, but causes a checker error
+// void class { [x?.["y"]] = 1 }    // legal parse, but causes a checker error
+// void class { [x?.()] = 1 }       // legal parse, but causes a checker error
+// void class { [new f?.()] = 1 }   // legal parse, but causes a checker error
+void class { [Symbol?.toStringTag] = "" }
+>Symbol?.toStringTag : Symbol(SymbolConstructor.toStringTag, Decl(lib.es2015.symbol.wellknown.d.ts, --, --))
+>Symbol : Symbol(Symbol, Decl(lib.es2015.symbol.wellknown.d.ts, --, --), Decl(lib.es2015.symbol.d.ts, --, --), Decl(lib.es2015.symbol.d.ts, --, --))
+>toStringTag : Symbol(SymbolConstructor.toStringTag, Decl(lib.es2015.symbol.wellknown.d.ts, --, --))
+
+// - property declarations
+void class { a = x?.y }
+>a : Symbol((Anonymous class).a, Decl(generalParsingOk.ts, 20, 12))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void class { a = x?.["y"] }
+>a : Symbol((Anonymous class).a, Decl(generalParsingOk.ts, 21, 12))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void class { a = x?.() }
+>a : Symbol((Anonymous class).a, Decl(generalParsingOk.ts, 22, 12))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void class { a = new x?.() }
+>a : Symbol((Anonymous class).a, Decl(generalParsingOk.ts, 23, 12))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// - heritage clauses
+void class extends M?.y {}
+>M?.y : Symbol(M.y, Decl(declarations.d.ts, 10, 21))
+>M : Symbol(M, Decl(declarations.d.ts, 9, 32))
+>y : Symbol(M.y, Decl(declarations.d.ts, 10, 21))
+
+void class extends M?.["y"] {}
+>M : Symbol(M, Decl(declarations.d.ts, 9, 32))
+>"y" : Symbol(M.y, Decl(declarations.d.ts, 10, 21))
+
+void class extends M?.z<number> {}
+>M?.z : Symbol(M.z, Decl(declarations.d.ts, 11, 21))
+>M : Symbol(M, Decl(declarations.d.ts, 9, 32))
+>z : Symbol(M.z, Decl(declarations.d.ts, 11, 21))
+
+// - class decorators
+@x?.y class C1 {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>C1 : Symbol(C1, Decl(generalParsingOk.ts, 27, 34))
+
+@x?.["y"] class C2 {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>C2 : Symbol(C2, Decl(generalParsingOk.ts, 29, 17))
+
+@x?.() class C3 {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>C3 : Symbol(C3, Decl(generalParsingOk.ts, 30, 21))
+
+@new x?.() class C4 {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>C4 : Symbol(C4, Decl(generalParsingOk.ts, 31, 18))
+
+// - member decorators
+class C5 { @x?.y m() {} }
+>C5 : Symbol(C5, Decl(generalParsingOk.ts, 32, 22))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>m : Symbol(C5.m, Decl(generalParsingOk.ts, 34, 10))
+
+class C6 { @x?.["y"] m() {} } // allowed as ?.[ is not ambiguous with computed property names
+>C6 : Symbol(C6, Decl(generalParsingOk.ts, 34, 25))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>m : Symbol(C6.m, Decl(generalParsingOk.ts, 35, 10))
+
+class C7 { @x?.() m() {} }
+>C7 : Symbol(C7, Decl(generalParsingOk.ts, 35, 29))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>m : Symbol(C7.m, Decl(generalParsingOk.ts, 36, 10))
+
+class C8 { @new x?.() m () {} }
+>C8 : Symbol(C8, Decl(generalParsingOk.ts, 36, 26))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>m : Symbol(C8.m, Decl(generalParsingOk.ts, 37, 10))
+
+// - parameter decorators
+class C9 { m(@x?.y a) {} }
+>C9 : Symbol(C9, Decl(generalParsingOk.ts, 37, 31))
+>m : Symbol(C9.m, Decl(generalParsingOk.ts, 39, 10))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 39, 13))
+
+class C10 { m(@x?.["y"] a) {} }
+>C10 : Symbol(C10, Decl(generalParsingOk.ts, 39, 26))
+>m : Symbol(C10.m, Decl(generalParsingOk.ts, 40, 11))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 40, 14))
+
+class C11 { m(@x?.() a) {} }
+>C11 : Symbol(C11, Decl(generalParsingOk.ts, 40, 31))
+>m : Symbol(C11.m, Decl(generalParsingOk.ts, 41, 11))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 41, 14))
+
+class C12 { m(@new x?.() a) {} }
+>C12 : Symbol(C12, Decl(generalParsingOk.ts, 41, 28))
+>m : Symbol(C12.m, Decl(generalParsingOk.ts, 42, 11))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 42, 14))
+
+// functions
+// - parameters
+void function (a = x?.y) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 46, 15))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void function (a = x?.["y"]) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 47, 15))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void function (a = x?.()) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 48, 15))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void function (a = new x?.()) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 49, 15))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// - binding elements
+//   - initializers
+void function ({ a = x?.y }) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 52, 16))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void function ({ a = x?.["y"] }) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 53, 16))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void function ({ a = x?.() }) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 54, 16))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void function ({ a = new x?.() }) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 55, 16))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+//   - computed properties
+void function ({ [x?.y]: a }) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 57, 16))
+
+void function ({ [x?.["y"]]: a }) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 58, 16))
+
+void function ({ [x?.()]: a }) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 59, 16))
+
+void function ({ [new x?.()]: a }) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 60, 16))
+
+// arrow functions
+// - parameters
+((a = x?.y) => {});
+>a : Symbol(a, Decl(generalParsingOk.ts, 64, 2))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+((a = x?.["y"]) => {});
+>a : Symbol(a, Decl(generalParsingOk.ts, 65, 2))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+((a = x?.()) => {});
+>a : Symbol(a, Decl(generalParsingOk.ts, 66, 2))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+((a = new x?.()) => {});
+>a : Symbol(a, Decl(generalParsingOk.ts, 67, 2))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// - expression bodies
+(() => x?.y);
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+(() => x?.["y"]);
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+(() => x?.());
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+(() => new x?.());
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// parenthesis
+(x?.y);
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// comma
+x?.y, f();
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>f : Symbol(f, Decl(declarations.d.ts, 2, 11))
+
+f(), x?.y;
+>f : Symbol(f, Decl(declarations.d.ts, 2, 11))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// conditional
+x?.y ? 0 : 1
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+0 ? x?.y : 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+0 ? 1 : x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// binary
+x?.y + 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y - 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y * 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y / 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y ** 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y % 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y ^ 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y & 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y | 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y << 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y >> 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y >>> 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y && 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y || 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y == 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y === 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y != 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y !== 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y < 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y <= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y > 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y >= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 + x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 - x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 * x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 / x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 ** x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 % x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 ^ x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 & x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 | x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 << x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 >> x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 >>> x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 && x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 || x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 == x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 === x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 != x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 !== x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 < x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 <= x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 > x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 >= x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// prefix unary
++x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+-x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+!x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+~x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// unary
+void x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+typeof x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void function * () { yield x?.y; }
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void async function() { await x?.y; }
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// notnull
+x?.y!.z;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// assertions
+<string>x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y as string;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// array literals
+[x?.y];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+[, x?.y];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+[...x?.y];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// literals
+1?.toString(); // no need for `..`
+>1?.toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+
+1.?.toString();
+>1.?.toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+
+.0?.toString();
+>.0?.toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+
+4e3?.toString();
+>4e3?.toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+
+1.e3?.toString();
+>1.e3?.toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+
+""?.toString();
+>""?.toString : Symbol(String.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(String.toString, Decl(lib.es5.d.ts, --, --))
+
+''?.toString();
+>''?.toString : Symbol(String.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(String.toString, Decl(lib.es5.d.ts, --, --))
+
+``?.toString();
+>``?.toString : Symbol(String.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(String.toString, Decl(lib.es5.d.ts, --, --))
+
+/./?.toString();
+>/./?.toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+
+/./g?.toString();
+>/./g?.toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+
+true?.toString();
+>true?.toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+
+false?.toString();
+>false?.toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+
+// templates
+`${x?.y}`;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// variables
+var v = x?.y;
+>v : Symbol(v, Decl(generalParsingOk.ts, 174, 3), Decl(generalParsingOk.ts, 175, 5), Decl(generalParsingOk.ts, 176, 5), Decl(generalParsingOk.ts, 177, 5), Decl(generalParsingOk.ts, 178, 5), Decl(generalParsingOk.ts, 179, 5))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+var [v] = x?.y;
+>v : Symbol(v, Decl(generalParsingOk.ts, 174, 3), Decl(generalParsingOk.ts, 175, 5), Decl(generalParsingOk.ts, 176, 5), Decl(generalParsingOk.ts, 177, 5), Decl(generalParsingOk.ts, 178, 5), Decl(generalParsingOk.ts, 179, 5))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+var [v = x?.y] = [1];
+>v : Symbol(v, Decl(generalParsingOk.ts, 174, 3), Decl(generalParsingOk.ts, 175, 5), Decl(generalParsingOk.ts, 176, 5), Decl(generalParsingOk.ts, 177, 5), Decl(generalParsingOk.ts, 178, 5), Decl(generalParsingOk.ts, 179, 5))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+var {v} = x?.y;
+>v : Symbol(v, Decl(generalParsingOk.ts, 174, 3), Decl(generalParsingOk.ts, 175, 5), Decl(generalParsingOk.ts, 176, 5), Decl(generalParsingOk.ts, 177, 5), Decl(generalParsingOk.ts, 178, 5), Decl(generalParsingOk.ts, 179, 5))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+var {v = x?.y} = {v:1};
+>v : Symbol(v, Decl(generalParsingOk.ts, 174, 3), Decl(generalParsingOk.ts, 175, 5), Decl(generalParsingOk.ts, 176, 5), Decl(generalParsingOk.ts, 177, 5), Decl(generalParsingOk.ts, 178, 5), Decl(generalParsingOk.ts, 179, 5))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>v : Symbol(v, Decl(generalParsingOk.ts, 178, 18))
+
+var {[x?.y]: v} = null;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>v : Symbol(v, Decl(generalParsingOk.ts, 174, 3), Decl(generalParsingOk.ts, 175, 5), Decl(generalParsingOk.ts, 176, 5), Decl(generalParsingOk.ts, 177, 5), Decl(generalParsingOk.ts, 178, 5), Decl(generalParsingOk.ts, 179, 5))
+
+// if/else if
+if (x?.y) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+if (1) {} else if (x?.y) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// switch
+switch (x?.y) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+switch (1) { case x?.y: break; }
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// do/while
+do {} while (x?.y)
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+while (x?.y) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// for
+for (x?.y; x?.y; x?.y);
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// for..in
+for (x?.y in {});
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// for..of
+for (x?.y of []);
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// enums
+enum E {
+>E : Symbol(E, Decl(generalParsingOk.ts, 200, 17))
+
+    a = x?.y
+>a : Symbol(E.a, Decl(generalParsingOk.ts, 203, 8))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+}
+
+=== tests/cases/conformance/emitter/es3/safeNavigation/exportsOk.ts ===
+export default x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+

tests/baselines/reference/emitter.safeNavigation.es5.js

@@ -0,0 +1,874 @@
+//// [tests/cases/conformance/emitter/es5/safeNavigation/emitter.safeNavigation.es5.ts] ////
+
+//// [declarations.d.ts]
+declare var x: any;
+declare var y: any;
+declare var f: ({
+    (): void;
+    <T>(): void;
+    new (): any;
+    new <T>(): any;
+}) | undefined;
+declare var o: { y: typeof f; }
+declare class Base { x(): any; }
+declare namespace M {
+    export class y {}
+    export class z<T> {}
+}
+//// [propertyAccessOk.ts]
+x.y
+x?.y
+x?.y.z
+x.y?.z
+x?.y?.z
+//// [elementAccessOk.ts]
+x["y"]
+x?.["y"]
+x?.["y"]["z"]
+x["y"]?.["z"]
+x?.["y"]?.["z"]
+//// [callExpressionOk.ts]
+x()
+x?.()
+x.y?.()
+x["y"]?.()
+f?.<number>()
+o.y?.<number>()
+o["y"]?.<number>()
+//// [newExpressionOk.ts]
+new x()
+new x.y?.()
+new x["y"]?.()
+new f?.<number>()
+new o.y?.<number>()
+new o["y"]?.<number>()
+//// [mixedOk.ts]
+x?.y?.["z"]
+x?.["y"]?.z
+x?.y()
+x?.y?.()
+o?.y<number>()
+o?.y?.<number>()
+x?.["z"]()
+x?.["z"]?.()
+o?.["y"]<number>()
+o?.["y"]?.<number>()
+//// [mutationOk.ts]
+x?.y = 1
+x?.y += 1;
+x?.y -= 1;
+x?.y *= 1;
+x?.y /= 1;
+x?.y %= 1;
+x?.y **= 1;
+x?.y |= 1;
+x?.y &= 1;
+x?.y ^= 1;
+x?.y <<= 1;
+x?.y >>= 1;
+x?.y >>>= 1;
+x?.y++;
+x?.y--;
+++x?.y;
+--x?.y;
+delete x?.y;
+x?.["y"] = 1
+x?.["y"] += 1;
+x?.["y"] -= 1;
+x?.["y"] *= 1;
+x?.["y"] /= 1;
+x?.["y"] %= 1;
+x?.["y"] **= 1;
+x?.["y"] |= 1;
+x?.["y"] &= 1;
+x?.["y"] ^= 1;
+x?.["y"] <<= 1;
+x?.["y"] >>= 1;
+x?.["y"] >>>= 1;
+x?.["y"]++;
+x?.["y"]--;
+++x?.["y"];
+--x?.["y"];
+delete x?.["y"];
+//// [arrayAssignmentPatternOk.ts]
+[x?.y] = [1];
+[x?.["y"]] = [1];
+[...x?.y] = [1];
+[...x?.["y"]] = [1];
+//// [objectAssignmentPatternOk.ts]
+({ a: x?.y } = { a: 1 });
+({ a: x?.["y"] } = { a: 1 });
+//// [questionDotDigitIsConditionalOk.ts]
+x?.3:1;
+//// [superPropertyInvocationOk.ts]
+// supported for invocation of super property
+void class extends Base {
+    m() {
+        super.x?.();
+    }
+}
+
+//// [generalParsingOk.ts]
+// object literals
+// - computed property names
+void { [x?.y]: 1 }
+void { [x?.["y"]]: 1 }
+void { [x?.()]: 1 }
+void { [new x?.()]: 1 }
+// - property assignments
+void { a: x?.y }
+void { a: x?.["y"] }
+void { a: x?.() }
+void { a: new x?.() }
+
+// classes
+// - computed property names
+// void class { [x?.y] = 1 }        // legal parse, but causes a checker error
+// void class { [x?.["y"]] = 1 }    // legal parse, but causes a checker error
+// void class { [x?.()] = 1 }       // legal parse, but causes a checker error
+// void class { [new f?.()] = 1 }   // legal parse, but causes a checker error
+void class { [Symbol?.toStringTag] = "" }
+// - property declarations
+void class { a = x?.y }
+void class { a = x?.["y"] }
+void class { a = x?.() }
+void class { a = new x?.() }
+// - heritage clauses
+void class extends M?.y {}
+void class extends M?.["y"] {}
+void class extends M?.z<number> {}
+// - class decorators
+@x?.y class C1 {}
+@x?.["y"] class C2 {}
+@x?.() class C3 {}
+@new x?.() class C4 {}
+// - member decorators
+class C5 { @x?.y m() {} }
+class C6 { @x?.["y"] m() {} } // allowed as ?.[ is not ambiguous with computed property names
+class C7 { @x?.() m() {} }
+class C8 { @new x?.() m () {} }
+// - parameter decorators
+class C9 { m(@x?.y a) {} }
+class C10 { m(@x?.["y"] a) {} }
+class C11 { m(@x?.() a) {} }
+class C12 { m(@new x?.() a) {} }
+
+// functions
+// - parameters
+void function (a = x?.y) {}
+void function (a = x?.["y"]) {}
+void function (a = x?.()) {}
+void function (a = new x?.()) {}
+// - binding elements
+//   - initializers
+void function ({ a = x?.y }) {}
+void function ({ a = x?.["y"] }) {}
+void function ({ a = x?.() }) {}
+void function ({ a = new x?.() }) {}
+//   - computed properties
+void function ({ [x?.y]: a }) {}
+void function ({ [x?.["y"]]: a }) {}
+void function ({ [x?.()]: a }) {}
+void function ({ [new x?.()]: a }) {}
+
+// arrow functions
+// - parameters
+((a = x?.y) => {});
+((a = x?.["y"]) => {});
+((a = x?.()) => {});
+((a = new x?.()) => {});
+// - expression bodies
+(() => x?.y);
+(() => x?.["y"]);
+(() => x?.());
+(() => new x?.());
+
+// parenthesis
+(x?.y);
+
+// comma
+x?.y, f();
+f(), x?.y;
+
+// conditional
+x?.y ? 0 : 1
+0 ? x?.y : 1;
+0 ? 1 : x?.y;
+
+// binary
+x?.y + 1;
+x?.y - 1;
+x?.y * 1;
+x?.y / 1;
+x?.y ** 1;
+x?.y % 1;
+x?.y ^ 1;
+x?.y & 1;
+x?.y | 1;
+x?.y << 1;
+x?.y >> 1;
+x?.y >>> 1;
+x?.y && 1;
+x?.y || 1;
+x?.y == 1;
+x?.y === 1;
+x?.y != 1;
+x?.y !== 1;
+x?.y < 1;
+x?.y <= 1;
+x?.y > 1;
+x?.y >= 1;
+1 + x?.y;
+1 - x?.y;
+1 * x?.y;
+1 / x?.y;
+1 ** x?.y;
+1 % x?.y;
+1 ^ x?.y;
+1 & x?.y;
+1 | x?.y;
+1 << x?.y;
+1 >> x?.y;
+1 >>> x?.y;
+1 && x?.y;
+1 || x?.y;
+1 == x?.y;
+1 === x?.y;
+1 != x?.y;
+1 !== x?.y;
+1 < x?.y;
+1 <= x?.y;
+1 > x?.y;
+1 >= x?.y;
+
+// prefix unary
++x?.y;
+-x?.y;
+!x?.y;
+~x?.y;
+
+// unary
+void x?.y;
+typeof x?.y;
+void function * () { yield x?.y; }
+void async function() { await x?.y; }
+
+// notnull
+x?.y!.z;
+
+// assertions
+<string>x?.y;
+x?.y as string;
+
+// array literals
+[x?.y];
+[, x?.y];
+[...x?.y];
+
+// literals
+1?.toString(); // no need for `..`
+1.?.toString();
+.0?.toString();
+4e3?.toString();
+1.e3?.toString();
+""?.toString();
+''?.toString();
+``?.toString();
+/./?.toString();
+/./g?.toString();
+true?.toString();
+false?.toString();
+
+// templates
+`${x?.y}`;
+
+// variables
+var v = x?.y;
+var [v] = x?.y;
+var [v = x?.y] = [1];
+var {v} = x?.y;
+var {v = x?.y} = {v:1};
+var {[x?.y]: v} = null;
+
+// if/else if
+if (x?.y) {}
+if (1) {} else if (x?.y) {}
+
+// switch
+switch (x?.y) {}
+switch (1) { case x?.y: break; }
+
+// do/while
+do {} while (x?.y)
+while (x?.y) {}
+
+// for
+for (x?.y; x?.y; x?.y);
+
+// for..in
+for (x?.y in {});
+
+// for..of
+for (x?.y of []);
+
+// enums
+enum E {
+    a = x?.y
+}
+
+//// [exportsOk.ts]
+export default x?.y;
+
+//// [propertyAccessOk.js]
+x.y;
+x == null ? void 0 : x.y;
+(x == null ? void 0 : x.y).z;
+(_a = x.y) == null ? void 0 : _a.z;
+(_b = x == null ? void 0 : x.y) == null ? void 0 : _b.z;
+var _a, _b;
+//// [elementAccessOk.js]
+x["y"];
+x == null ? void 0 : x["y"];
+(x == null ? void 0 : x["y"])["z"];
+(_a = x["y"]) == null ? void 0 : _a["z"];
+(_b = x == null ? void 0 : x["y"]) == null ? void 0 : _b["z"];
+var _a, _b;
+//// [callExpressionOk.js]
+x();
+x == null ? void 0 : x();
+(_a = x.y) == null ? void 0 : _a.call(x);
+(_b = x["y"]) == null ? void 0 : _b.call(x);
+f == null ? void 0 : f();
+(_c = o.y) == null ? void 0 : _c.call(o);
+(_d = o["y"]) == null ? void 0 : _d.call(o);
+var _a, _b, _c, _d;
+//// [newExpressionOk.js]
+new x();
+(_a = x.y) == null ? void 0 : new _a();
+(_b = x["y"]) == null ? void 0 : new _b();
+f == null ? void 0 : new f();
+(_c = o.y) == null ? void 0 : new _c();
+(_d = o["y"]) == null ? void 0 : new _d();
+var _a, _b, _c, _d;
+//// [mixedOk.js]
+(_a = x == null ? void 0 : x.y) == null ? void 0 : _a["z"];
+(_b = x == null ? void 0 : x["y"]) == null ? void 0 : _b.z;
+(x == null ? void 0 : x.y)();
+(_c = x == null ? void 0 : x.y) == null ? void 0 : _c.call(x);
+(o == null ? void 0 : o.y)();
+(_d = o == null ? void 0 : o.y) == null ? void 0 : _d.call(o);
+(x == null ? void 0 : x["z"])();
+(_e = x == null ? void 0 : x["z"]) == null ? void 0 : _e.call(x);
+(o == null ? void 0 : o["y"])();
+(_f = o == null ? void 0 : o["y"]) == null ? void 0 : _f.call(o);
+var _a, _b, _c, _d, _e, _f;
+//// [mutationOk.js]
+_a = 1, x == null ? _a : x.y = _a;
+_b = 1, x == null ? _b : x.y += _b;
+_c = 1, x == null ? _c : x.y -= _c;
+_d = 1, x == null ? _d : x.y *= _d;
+_e = 1, x == null ? _e : x.y /= _e;
+_f = 1, x == null ? _f : x.y %= _f;
+_g = 1, x == null ? _g : (_h = x).y = Math.pow(_h.y, _g);
+_j = 1, x == null ? _j : x.y |= _j;
+_k = 1, x == null ? _k : x.y &= _k;
+_l = 1, x == null ? _l : x.y ^= _l;
+_m = 1, x == null ? _m : x.y <<= _m;
+_o = 1, x == null ? _o : x.y >>= _o;
+_p = 1, x == null ? _p : x.y >>>= _p;
+x == null ? void 0 : x.y++;
+x == null ? void 0 : x.y--;
+x == null ? void 0 : ++x.y;
+x == null ? void 0 : --x.y;
+x == null ? true : delete x.y;
+_q = 1, x == null ? _q : x["y"] = _q;
+_r = 1, x == null ? _r : x["y"] += _r;
+_s = 1, x == null ? _s : x["y"] -= _s;
+_t = 1, x == null ? _t : x["y"] *= _t;
+_u = 1, x == null ? _u : x["y"] /= _u;
+_v = 1, x == null ? _v : x["y"] %= _v;
+_w = 1, x == null ? _w : (_x = x)[_y = "y"] = Math.pow(_x[_y], _w);
+_z = 1, x == null ? _z : x["y"] |= _z;
+_0 = 1, x == null ? _0 : x["y"] &= _0;
+_1 = 1, x == null ? _1 : x["y"] ^= _1;
+_2 = 1, x == null ? _2 : x["y"] <<= _2;
+_3 = 1, x == null ? _3 : x["y"] >>= _3;
+_4 = 1, x == null ? _4 : x["y"] >>>= _4;
+x == null ? void 0 : x["y"]++;
+x == null ? void 0 : x["y"]--;
+x == null ? void 0 : ++x["y"];
+x == null ? void 0 : --x["y"];
+x == null ? true : delete x["y"];
+var _a, _b, _c, _d, _e, _f, _g, _j, _k, _l, _m, _o, _p, _q, _r, _s, _t, _u, _v, _w, _z, _0, _1, _2, _3, _4;
+var _h, _x, _y;
+//// [arrayAssignmentPatternOk.js]
+_a = [1], (x == null ? void 0 : x.y = _a[0], _a);
+_b = [1], (x == null ? void 0 : x["y"] = _b[0], _b);
+_c = [1], (x == null ? void 0 : x.y = _c.slice(0), _c);
+_d = [1], (x == null ? void 0 : x["y"] = _d.slice(0), _d);
+var _a, _b, _c, _d;
+//// [objectAssignmentPatternOk.js]
+(_a = { a: 1 }, (x == null ? void 0 : x.y = _a.a, _a));
+(_b = { a: 1 }, (x == null ? void 0 : x["y"] = _b.a, _b));
+var _a, _b;
+//// [questionDotDigitIsConditionalOk.js]
+x ? .3 : 1;
+//// [superPropertyInvocationOk.js]
+var __extends = (this && this.__extends) || (function () {
+    var extendStatics = Object.setPrototypeOf ||
+        ({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) ||
+        function (d, b) { for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p]; };
+    return function (d, b) {
+        extendStatics(d, b);
+        function __() { this.constructor = d; }
+        d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
+    };
+})();
+// supported for invocation of super property
+void (function (_super) {
+    __extends(class_1, _super);
+    function class_1() {
+        return _super !== null && _super.apply(this, arguments) || this;
+    }
+    class_1.prototype.m = function () {
+        (_a = _super.prototype.x) == null ? void 0 : _a.call(this);
+        var _a;
+    };
+    return class_1;
+}(Base));
+//// [generalParsingOk.js]
+var __extends = (this && this.__extends) || (function () {
+    var extendStatics = Object.setPrototypeOf ||
+        ({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) ||
+        function (d, b) { for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p]; };
+    return function (d, b) {
+        extendStatics(d, b);
+        function __() { this.constructor = d; }
+        d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
+    };
+})();
+var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
+    var c = arguments.length, r = c < 3 ? target : desc === null ? desc = Object.getOwnPropertyDescriptor(target, key) : desc, d;
+    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") r = Reflect.decorate(decorators, target, key, desc);
+    else for (var i = decorators.length - 1; i >= 0; i--) if (d = decorators[i]) r = (c < 3 ? d(r) : c > 3 ? d(target, key, r) : d(target, key)) || r;
+    return c > 3 && r && Object.defineProperty(target, key, r), r;
+};
+var __param = (this && this.__param) || function (paramIndex, decorator) {
+    return function (target, key) { decorator(target, key, paramIndex); }
+};
+var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    return new (P || (P = Promise))(function (resolve, reject) {
+        function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
+        function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
+        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        step((generator = generator.apply(thisArg, _arguments || [])).next());
+    });
+};
+var __generator = (this && this.__generator) || function (thisArg, body) {
+    var _ = { label: 0, sent: function() { if (t[0] & 1) throw t[1]; return t[1]; }, trys: [], ops: [] }, f, y, t, g;
+    return g = { next: verb(0), "throw": verb(1), "return": verb(2) }, typeof Symbol === "function" && (g[Symbol.iterator] = function() { return this; }), g;
+    function verb(n) { return function (v) { return step([n, v]); }; }
+    function step(op) {
+        if (f) throw new TypeError("Generator is already executing.");
+        while (_) try {
+            if (f = 1, y && (t = y[op[0] & 2 ? "return" : op[0] ? "throw" : "next"]) && !(t = t.call(y, op[1])).done) return t;
+            if (y = 0, t) op = [0, t.value];
+            switch (op[0]) {
+                case 0: case 1: t = op; break;
+                case 4: _.label++; return { value: op[1], done: false };
+                case 5: _.label++; y = op[1]; op = [0]; continue;
+                case 7: op = _.ops.pop(); _.trys.pop(); continue;
+                default:
+                    if (!(t = _.trys, t = t.length > 0 && t[t.length - 1]) && (op[0] === 6 || op[0] === 2)) { _ = 0; continue; }
+                    if (op[0] === 3 && (!t || (op[1] > t[0] && op[1] < t[3]))) { _.label = op[1]; break; }
+                    if (op[0] === 6 && _.label < t[1]) { _.label = t[1]; t = op; break; }
+                    if (t && _.label < t[2]) { _.label = t[2]; _.ops.push(op); break; }
+                    if (t[2]) _.ops.pop();
+                    _.trys.pop(); continue;
+            }
+            op = body.call(thisArg, _);
+        } catch (e) { op = [6, e]; y = 0; } finally { f = t = 0; }
+        if (op[0] & 5) throw op[1]; return { value: op[0] ? op[1] : void 0, done: true };
+    }
+};
+// object literals
+// - computed property names
+void (_a = {}, _a[x == null ? void 0 : x.y] = 1, _a);
+void (_b = {}, _b[x == null ? void 0 : x["y"]] = 1, _b);
+void (_c = {}, _c[x == null ? void 0 : x()] = 1, _c);
+void (_d = {}, _d[x == null ? void 0 : new x()] = 1, _d);
+// - property assignments
+void { a: x == null ? void 0 : x.y };
+void { a: x == null ? void 0 : x["y"] };
+void { a: x == null ? void 0 : x() };
+void { a: x == null ? void 0 : new x() };
+// classes
+// - computed property names
+// void class { [x?.y] = 1 }        // legal parse, but causes a checker error
+// void class { [x?.["y"]] = 1 }    // legal parse, but causes a checker error
+// void class { [x?.()] = 1 }       // legal parse, but causes a checker error
+// void class { [new f?.()] = 1 }   // legal parse, but causes a checker error
+void (function () {
+    function class_1() {
+        this[Symbol == null ? void 0 : Symbol.toStringTag] = "";
+    }
+    return class_1;
+}());
+// - property declarations
+void (function () {
+    function class_2() {
+        this.a = x == null ? void 0 : x.y;
+    }
+    return class_2;
+}());
+void (function () {
+    function class_3() {
+        this.a = x == null ? void 0 : x["y"];
+    }
+    return class_3;
+}());
+void (function () {
+    function class_4() {
+        this.a = x == null ? void 0 : x();
+    }
+    return class_4;
+}());
+void (function () {
+    function class_5() {
+        this.a = x == null ? void 0 : new x();
+    }
+    return class_5;
+}());
+// - heritage clauses
+void (function (_super) {
+    __extends(class_6, _super);
+    function class_6() {
+        return _super !== null && _super.apply(this, arguments) || this;
+    }
+    return class_6;
+}((M == null ? void 0 : M.y)));
+void (function (_super) {
+    __extends(class_7, _super);
+    function class_7() {
+        return _super !== null && _super.apply(this, arguments) || this;
+    }
+    return class_7;
+}((M == null ? void 0 : M["y"])));
+void (function (_super) {
+    __extends(class_8, _super);
+    function class_8() {
+        return _super !== null && _super.apply(this, arguments) || this;
+    }
+    return class_8;
+}((M == null ? void 0 : M.z)));
+// - class decorators
+var C1 = (function () {
+    function C1() {
+    }
+    return C1;
+}());
+C1 = __decorate([
+    x == null ? void 0 : x.y
+], C1);
+var C2 = (function () {
+    function C2() {
+    }
+    return C2;
+}());
+C2 = __decorate([
+    x == null ? void 0 : x["y"]
+], C2);
+var C3 = (function () {
+    function C3() {
+    }
+    return C3;
+}());
+C3 = __decorate([
+    x == null ? void 0 : x()
+], C3);
+var C4 = (function () {
+    function C4() {
+    }
+    return C4;
+}());
+C4 = __decorate([
+    x == null ? void 0 : new x()
+], C4);
+// - member decorators
+var C5 = (function () {
+    function C5() {
+    }
+    C5.prototype.m = function () { };
+    return C5;
+}());
+__decorate([
+    x == null ? void 0 : x.y
+], C5.prototype, "m", null);
+var C6 = (function () {
+    function C6() {
+    }
+    C6.prototype.m = function () { };
+    return C6;
+}()); // allowed as ?.[ is not ambiguous with computed property names
+__decorate([
+    x == null ? void 0 : x["y"]
+], C6.prototype, "m", null);
+var C7 = (function () {
+    function C7() {
+    }
+    C7.prototype.m = function () { };
+    return C7;
+}());
+__decorate([
+    x == null ? void 0 : x()
+], C7.prototype, "m", null);
+var C8 = (function () {
+    function C8() {
+    }
+    C8.prototype.m = function () { };
+    return C8;
+}());
+__decorate([
+    x == null ? void 0 : new x()
+], C8.prototype, "m", null);
+// - parameter decorators
+var C9 = (function () {
+    function C9() {
+    }
+    C9.prototype.m = function (a) { };
+    return C9;
+}());
+__decorate([
+    __param(0, x == null ? void 0 : x.y)
+], C9.prototype, "m", null);
+var C10 = (function () {
+    function C10() {
+    }
+    C10.prototype.m = function (a) { };
+    return C10;
+}());
+__decorate([
+    __param(0, x == null ? void 0 : x["y"])
+], C10.prototype, "m", null);
+var C11 = (function () {
+    function C11() {
+    }
+    C11.prototype.m = function (a) { };
+    return C11;
+}());
+__decorate([
+    __param(0, x == null ? void 0 : x())
+], C11.prototype, "m", null);
+var C12 = (function () {
+    function C12() {
+    }
+    C12.prototype.m = function (a) { };
+    return C12;
+}());
+__decorate([
+    __param(0, x == null ? void 0 : new x())
+], C12.prototype, "m", null);
+// functions
+// - parameters
+void function (a) {
+    if (a === void 0) { a = x == null ? void 0 : x.y; }
+};
+void function (a) {
+    if (a === void 0) { a = x == null ? void 0 : x["y"]; }
+};
+void function (a) {
+    if (a === void 0) { a = x == null ? void 0 : x(); }
+};
+void function (a) {
+    if (a === void 0) { a = x == null ? void 0 : new x(); }
+};
+// - binding elements
+//   - initializers
+void function (_a) {
+    var _b = _a.a, a = _b === void 0 ? x == null ? void 0 : x.y : _b;
+};
+void function (_a) {
+    var _b = _a.a, a = _b === void 0 ? x == null ? void 0 : x["y"] : _b;
+};
+void function (_a) {
+    var _b = _a.a, a = _b === void 0 ? x == null ? void 0 : x() : _b;
+};
+void function (_a) {
+    var _b = _a.a, a = _b === void 0 ? x == null ? void 0 : new x() : _b;
+};
+//   - computed properties
+void function (_a) {
+    var _b = x == null ? void 0 : x.y, a = _a[_b];
+};
+void function (_a) {
+    var _b = x == null ? void 0 : x["y"], a = _a[_b];
+};
+void function (_a) {
+    var _b = x == null ? void 0 : x(), a = _a[_b];
+};
+void function (_a) {
+    var _b = x == null ? void 0 : new x(), a = _a[_b];
+}(function (a) {
+    if (a === void 0) { a = x == null ? void 0 : x.y; }
+});
+(function (a) {
+    if (a === void 0) { a = x == null ? void 0 : x["y"]; }
+});
+(function (a) {
+    if (a === void 0) { a = x == null ? void 0 : x(); }
+});
+(function (a) {
+    if (a === void 0) { a = x == null ? void 0 : new x(); }
+});
+// - expression bodies
+(function () { return x == null ? void 0 : x.y; });
+(function () { return x == null ? void 0 : x["y"]; });
+(function () { return x == null ? void 0 : x(); });
+(function () { return x == null ? void 0 : new x(); });
+// parenthesis
+(x == null ? void 0 : x.y);
+// comma
+x == null ? void 0 : x.y, f();
+f(), x == null ? void 0 : x.y;
+// conditional
+x == null ? void 0 : x.y ? 0 : 1;
+0 ? x == null ? void 0 : x.y : 1;
+0 ? 1 : x == null ? void 0 : x.y;
+// binary
+(x == null ? void 0 : x.y) + 1;
+(x == null ? void 0 : x.y) - 1;
+(x == null ? void 0 : x.y) * 1;
+(x == null ? void 0 : x.y) / 1;
+Math.pow((x == null ? void 0 : x.y), 1);
+(x == null ? void 0 : x.y) % 1;
+(x == null ? void 0 : x.y) ^ 1;
+(x == null ? void 0 : x.y) & 1;
+(x == null ? void 0 : x.y) | 1;
+(x == null ? void 0 : x.y) << 1;
+(x == null ? void 0 : x.y) >> 1;
+(x == null ? void 0 : x.y) >>> 1;
+(x == null ? void 0 : x.y) && 1;
+(x == null ? void 0 : x.y) || 1;
+(x == null ? void 0 : x.y) == 1;
+(x == null ? void 0 : x.y) === 1;
+(x == null ? void 0 : x.y) != 1;
+(x == null ? void 0 : x.y) !== 1;
+(x == null ? void 0 : x.y) < 1;
+(x == null ? void 0 : x.y) <= 1;
+(x == null ? void 0 : x.y) > 1;
+(x == null ? void 0 : x.y) >= 1;
+1 + (x == null ? void 0 : x.y);
+1 - (x == null ? void 0 : x.y);
+1 * (x == null ? void 0 : x.y);
+1 / (x == null ? void 0 : x.y);
+Math.pow(1, (x == null ? void 0 : x.y));
+1 % (x == null ? void 0 : x.y);
+1 ^ (x == null ? void 0 : x.y);
+1 & (x == null ? void 0 : x.y);
+1 | (x == null ? void 0 : x.y);
+1 << (x == null ? void 0 : x.y);
+1 >> (x == null ? void 0 : x.y);
+1 >>> (x == null ? void 0 : x.y);
+1 && (x == null ? void 0 : x.y);
+1 || (x == null ? void 0 : x.y);
+1 == (x == null ? void 0 : x.y);
+1 === (x == null ? void 0 : x.y);
+1 != (x == null ? void 0 : x.y);
+1 !== (x == null ? void 0 : x.y);
+1 < (x == null ? void 0 : x.y);
+1 <= (x == null ? void 0 : x.y);
+1 > (x == null ? void 0 : x.y);
+1 >= (x == null ? void 0 : x.y);
+// prefix unary
++(x == null ? void 0 : x.y);
+-(x == null ? void 0 : x.y);
+!(x == null ? void 0 : x.y);
+~(x == null ? void 0 : x.y);
+// unary
+void (x == null ? void 0 : x.y);
+typeof (x == null ? void 0 : x.y);
+void function () { return __generator(this, function (_a) {
+    switch (_a.label) {
+        case 0: return [4 /*yield*/, x == null ? void 0 : x.y];
+        case 1:
+            _a.sent();
+            return [2 /*return*/];
+    }
+}); };
+void function () {
+    return __awaiter(this, void 0, void 0, function () { return __generator(this, function (_a) {
+        switch (_a.label) {
+            case 0: return [4 /*yield*/, (x == null ? void 0 : x.y)];
+            case 1:
+                _a.sent();
+                return [2 /*return*/];
+        }
+    }); });
+};
+// notnull
+(x == null ? void 0 : x.y).z;
+// assertions
+x == null ? void 0 : x.y;
+x == null ? void 0 : x.y;
+// array literals
+[x == null ? void 0 : x.y];
+[, x == null ? void 0 : x.y];
+(x == null ? void 0 : x.y).slice();
+// literals
+((_e = 1) == null ? void 0 : _e.toString)(); // no need for `..`
+((_f = 1.) == null ? void 0 : _f.toString)();
+((_g = .0) == null ? void 0 : _g.toString)();
+((_h = 4e3) == null ? void 0 : _h.toString)();
+((_j = 1.e3) == null ? void 0 : _j.toString)();
+((_k = "") == null ? void 0 : _k.toString)();
+((_l = '') == null ? void 0 : _l.toString)();
+((_m = "") == null ? void 0 : _m.toString)();
+((_o = /./) == null ? void 0 : _o.toString)();
+((_p = /./g) == null ? void 0 : _p.toString)();
+((_q = true) == null ? void 0 : _q.toString)();
+((_r = false) == null ? void 0 : _r.toString)();
+// templates
+"" + (x == null ? void 0 : x.y);
+// variables
+var v = x == null ? void 0 : x.y;
+var v = (x == null ? void 0 : x.y)[0];
+var _s = [1][0], v = _s === void 0 ? x == null ? void 0 : x.y : _s;
+var v = (x == null ? void 0 : x.y).v;
+var _t = { v: 1 }.v, v = _t === void 0 ? x == null ? void 0 : x.y : _t;
+var _u = x == null ? void 0 : x.y, v = null[_u];
+// if/else if
+if (x == null ? void 0 : x.y) { }
+if (1) { }
+else if (x == null ? void 0 : x.y) { }
+// switch
+switch (x == null ? void 0 : x.y) {
+}
+switch (1) {
+    case x == null ? void 0 : x.y: break;
+}
+// do/while
+do { } while (x == null ? void 0 : x.y);
+while (x == null ? void 0 : x.y) { }
+// for
+for (x == null ? void 0 : x.y; x == null ? void 0 : x.y; x == null ? void 0 : x.y)
+    ;
+// for..in
+for ({ set value(_a) { x == null ? _a : x.y = _a; } }.value in {})
+    ;
+// for..of
+for (var _i = 0, _v = []; _i < _v.length; _i++) {
+    var _w = _v[_i];
+    x == null ? _w : x.y = _w;
+    ;
+}
+// enums
+var E;
+(function (E) {
+    E[E["a"] = x == null ? void 0 : x.y] = "a";
+})(E || (E = {}));
+var _e, _f, _g, _h, _j, _k, _l, _m, _o, _p, _q, _r, _w;
+var _a, _b, _c, _d;
+//// [exportsOk.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.default = x == null ? void 0 : x.y;

tests/baselines/reference/emitter.safeNavigation.es5.symbols

@@ -0,0 +1,858 @@
+=== tests/cases/conformance/emitter/es5/safeNavigation/declarations.d.ts ===
+declare var x: any;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+declare var y: any;
+>y : Symbol(y, Decl(declarations.d.ts, 1, 11))
+
+declare var f: ({
+>f : Symbol(f, Decl(declarations.d.ts, 2, 11))
+
+    (): void;
+    <T>(): void;
+>T : Symbol(T, Decl(declarations.d.ts, 4, 5))
+
+    new (): any;
+    new <T>(): any;
+>T : Symbol(T, Decl(declarations.d.ts, 6, 9))
+
+}) | undefined;
+declare var o: { y: typeof f; }
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+>f : Symbol(f, Decl(declarations.d.ts, 2, 11))
+
+declare class Base { x(): any; }
+>Base : Symbol(Base, Decl(declarations.d.ts, 8, 31))
+>x : Symbol(Base.x, Decl(declarations.d.ts, 9, 20))
+
+declare namespace M {
+>M : Symbol(M, Decl(declarations.d.ts, 9, 32))
+
+    export class y {}
+>y : Symbol(y, Decl(declarations.d.ts, 10, 21))
+
+    export class z<T> {}
+>z : Symbol(z, Decl(declarations.d.ts, 11, 21))
+>T : Symbol(T, Decl(declarations.d.ts, 12, 19))
+}
+=== tests/cases/conformance/emitter/es5/safeNavigation/propertyAccessOk.ts ===
+x.y
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y.z
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x.y?.z
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y?.z
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+=== tests/cases/conformance/emitter/es5/safeNavigation/elementAccessOk.ts ===
+x["y"]
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"]
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"]["z"]
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x["y"]?.["z"]
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"]?.["z"]
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+=== tests/cases/conformance/emitter/es5/safeNavigation/callExpressionOk.ts ===
+x()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x.y?.()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x["y"]?.()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+f?.<number>()
+>f : Symbol(f, Decl(declarations.d.ts, 2, 11))
+
+o.y?.<number>()
+>o.y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+o["y"]?.<number>()
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>"y" : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+=== tests/cases/conformance/emitter/es5/safeNavigation/newExpressionOk.ts ===
+new x()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+new x.y?.()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+new x["y"]?.()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+new f?.<number>()
+>f : Symbol(f, Decl(declarations.d.ts, 2, 11))
+
+new o.y?.<number>()
+>o.y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+new o["y"]?.<number>()
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>"y" : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+=== tests/cases/conformance/emitter/es5/safeNavigation/mixedOk.ts ===
+x?.y?.["z"]
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"]?.z
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y?.()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+o?.y<number>()
+>o?.y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+o?.y?.<number>()
+>o?.y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+x?.["z"]()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["z"]?.()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+o?.["y"]<number>()
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>"y" : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+o?.["y"]?.<number>()
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>"y" : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+=== tests/cases/conformance/emitter/es5/safeNavigation/mutationOk.ts ===
+x?.y = 1
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y += 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y -= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y *= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y /= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y %= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y **= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y |= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y &= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y ^= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y <<= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y >>= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y >>>= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y++;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y--;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+++x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+--x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+delete x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] = 1
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] += 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] -= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] *= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] /= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] %= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] **= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] |= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] &= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] ^= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] <<= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] >>= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] >>>= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"]++;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"]--;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+++x?.["y"];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+--x?.["y"];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+delete x?.["y"];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+=== tests/cases/conformance/emitter/es5/safeNavigation/arrayAssignmentPatternOk.ts ===
+[x?.y] = [1];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+[x?.["y"]] = [1];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+[...x?.y] = [1];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+[...x?.["y"]] = [1];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+=== tests/cases/conformance/emitter/es5/safeNavigation/objectAssignmentPatternOk.ts ===
+({ a: x?.y } = { a: 1 });
+>a : Symbol(a, Decl(objectAssignmentPatternOk.ts, 0, 2))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(objectAssignmentPatternOk.ts, 0, 16))
+
+({ a: x?.["y"] } = { a: 1 });
+>a : Symbol(a, Decl(objectAssignmentPatternOk.ts, 1, 2))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(objectAssignmentPatternOk.ts, 1, 20))
+
+=== tests/cases/conformance/emitter/es5/safeNavigation/questionDotDigitIsConditionalOk.ts ===
+x?.3:1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+=== tests/cases/conformance/emitter/es5/safeNavigation/superPropertyInvocationOk.ts ===
+// supported for invocation of super property
+void class extends Base {
+>Base : Symbol(Base, Decl(declarations.d.ts, 8, 31))
+
+    m() {
+>m : Symbol((Anonymous class).m, Decl(superPropertyInvocationOk.ts, 1, 25))
+
+        super.x?.();
+>super.x : Symbol(Base.x, Decl(declarations.d.ts, 9, 20))
+>super : Symbol(Base, Decl(declarations.d.ts, 8, 31))
+>x : Symbol(Base.x, Decl(declarations.d.ts, 9, 20))
+    }
+}
+
+=== tests/cases/conformance/emitter/es5/safeNavigation/generalParsingOk.ts ===
+// object literals
+// - computed property names
+void { [x?.y]: 1 }
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void { [x?.["y"]]: 1 }
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void { [x?.()]: 1 }
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void { [new x?.()]: 1 }
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// - property assignments
+void { a: x?.y }
+>a : Symbol(a, Decl(generalParsingOk.ts, 7, 6))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void { a: x?.["y"] }
+>a : Symbol(a, Decl(generalParsingOk.ts, 8, 6))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void { a: x?.() }
+>a : Symbol(a, Decl(generalParsingOk.ts, 9, 6))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void { a: new x?.() }
+>a : Symbol(a, Decl(generalParsingOk.ts, 10, 6))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// classes
+// - computed property names
+// void class { [x?.y] = 1 }        // legal parse, but causes a checker error
+// void class { [x?.["y"]] = 1 }    // legal parse, but causes a checker error
+// void class { [x?.()] = 1 }       // legal parse, but causes a checker error
+// void class { [new f?.()] = 1 }   // legal parse, but causes a checker error
+void class { [Symbol?.toStringTag] = "" }
+>Symbol?.toStringTag : Symbol(SymbolConstructor.toStringTag, Decl(lib.es2015.symbol.wellknown.d.ts, --, --))
+>Symbol : Symbol(Symbol, Decl(lib.es2015.symbol.wellknown.d.ts, --, --), Decl(lib.es2015.symbol.d.ts, --, --), Decl(lib.es2015.symbol.d.ts, --, --))
+>toStringTag : Symbol(SymbolConstructor.toStringTag, Decl(lib.es2015.symbol.wellknown.d.ts, --, --))
+
+// - property declarations
+void class { a = x?.y }
+>a : Symbol((Anonymous class).a, Decl(generalParsingOk.ts, 20, 12))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void class { a = x?.["y"] }
+>a : Symbol((Anonymous class).a, Decl(generalParsingOk.ts, 21, 12))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void class { a = x?.() }
+>a : Symbol((Anonymous class).a, Decl(generalParsingOk.ts, 22, 12))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void class { a = new x?.() }
+>a : Symbol((Anonymous class).a, Decl(generalParsingOk.ts, 23, 12))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// - heritage clauses
+void class extends M?.y {}
+>M?.y : Symbol(M.y, Decl(declarations.d.ts, 10, 21))
+>M : Symbol(M, Decl(declarations.d.ts, 9, 32))
+>y : Symbol(M.y, Decl(declarations.d.ts, 10, 21))
+
+void class extends M?.["y"] {}
+>M : Symbol(M, Decl(declarations.d.ts, 9, 32))
+>"y" : Symbol(M.y, Decl(declarations.d.ts, 10, 21))
+
+void class extends M?.z<number> {}
+>M?.z : Symbol(M.z, Decl(declarations.d.ts, 11, 21))
+>M : Symbol(M, Decl(declarations.d.ts, 9, 32))
+>z : Symbol(M.z, Decl(declarations.d.ts, 11, 21))
+
+// - class decorators
+@x?.y class C1 {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>C1 : Symbol(C1, Decl(generalParsingOk.ts, 27, 34))
+
+@x?.["y"] class C2 {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>C2 : Symbol(C2, Decl(generalParsingOk.ts, 29, 17))
+
+@x?.() class C3 {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>C3 : Symbol(C3, Decl(generalParsingOk.ts, 30, 21))
+
+@new x?.() class C4 {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>C4 : Symbol(C4, Decl(generalParsingOk.ts, 31, 18))
+
+// - member decorators
+class C5 { @x?.y m() {} }
+>C5 : Symbol(C5, Decl(generalParsingOk.ts, 32, 22))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>m : Symbol(C5.m, Decl(generalParsingOk.ts, 34, 10))
+
+class C6 { @x?.["y"] m() {} } // allowed as ?.[ is not ambiguous with computed property names
+>C6 : Symbol(C6, Decl(generalParsingOk.ts, 34, 25))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>m : Symbol(C6.m, Decl(generalParsingOk.ts, 35, 10))
+
+class C7 { @x?.() m() {} }
+>C7 : Symbol(C7, Decl(generalParsingOk.ts, 35, 29))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>m : Symbol(C7.m, Decl(generalParsingOk.ts, 36, 10))
+
+class C8 { @new x?.() m () {} }
+>C8 : Symbol(C8, Decl(generalParsingOk.ts, 36, 26))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>m : Symbol(C8.m, Decl(generalParsingOk.ts, 37, 10))
+
+// - parameter decorators
+class C9 { m(@x?.y a) {} }
+>C9 : Symbol(C9, Decl(generalParsingOk.ts, 37, 31))
+>m : Symbol(C9.m, Decl(generalParsingOk.ts, 39, 10))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 39, 13))
+
+class C10 { m(@x?.["y"] a) {} }
+>C10 : Symbol(C10, Decl(generalParsingOk.ts, 39, 26))
+>m : Symbol(C10.m, Decl(generalParsingOk.ts, 40, 11))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 40, 14))
+
+class C11 { m(@x?.() a) {} }
+>C11 : Symbol(C11, Decl(generalParsingOk.ts, 40, 31))
+>m : Symbol(C11.m, Decl(generalParsingOk.ts, 41, 11))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 41, 14))
+
+class C12 { m(@new x?.() a) {} }
+>C12 : Symbol(C12, Decl(generalParsingOk.ts, 41, 28))
+>m : Symbol(C12.m, Decl(generalParsingOk.ts, 42, 11))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 42, 14))
+
+// functions
+// - parameters
+void function (a = x?.y) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 46, 15))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void function (a = x?.["y"]) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 47, 15))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void function (a = x?.()) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 48, 15))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void function (a = new x?.()) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 49, 15))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// - binding elements
+//   - initializers
+void function ({ a = x?.y }) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 52, 16))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void function ({ a = x?.["y"] }) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 53, 16))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void function ({ a = x?.() }) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 54, 16))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void function ({ a = new x?.() }) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 55, 16))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+//   - computed properties
+void function ({ [x?.y]: a }) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 57, 16))
+
+void function ({ [x?.["y"]]: a }) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 58, 16))
+
+void function ({ [x?.()]: a }) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 59, 16))
+
+void function ({ [new x?.()]: a }) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 60, 16))
+
+// arrow functions
+// - parameters
+((a = x?.y) => {});
+>a : Symbol(a, Decl(generalParsingOk.ts, 64, 2))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+((a = x?.["y"]) => {});
+>a : Symbol(a, Decl(generalParsingOk.ts, 65, 2))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+((a = x?.()) => {});
+>a : Symbol(a, Decl(generalParsingOk.ts, 66, 2))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+((a = new x?.()) => {});
+>a : Symbol(a, Decl(generalParsingOk.ts, 67, 2))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// - expression bodies
+(() => x?.y);
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+(() => x?.["y"]);
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+(() => x?.());
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+(() => new x?.());
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// parenthesis
+(x?.y);
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// comma
+x?.y, f();
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>f : Symbol(f, Decl(declarations.d.ts, 2, 11))
+
+f(), x?.y;
+>f : Symbol(f, Decl(declarations.d.ts, 2, 11))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// conditional
+x?.y ? 0 : 1
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+0 ? x?.y : 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+0 ? 1 : x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// binary
+x?.y + 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y - 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y * 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y / 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y ** 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y % 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y ^ 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y & 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y | 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y << 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y >> 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y >>> 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y && 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y || 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y == 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y === 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y != 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y !== 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y < 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y <= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y > 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y >= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 + x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 - x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 * x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 / x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 ** x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 % x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 ^ x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 & x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 | x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 << x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 >> x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 >>> x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 && x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 || x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 == x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 === x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 != x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 !== x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 < x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 <= x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 > x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 >= x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// prefix unary
++x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+-x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+!x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+~x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// unary
+void x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+typeof x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void function * () { yield x?.y; }
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void async function() { await x?.y; }
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// notnull
+x?.y!.z;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// assertions
+<string>x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y as string;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// array literals
+[x?.y];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+[, x?.y];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+[...x?.y];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// literals
+1?.toString(); // no need for `..`
+>1?.toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+
+1.?.toString();
+>1.?.toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+
+.0?.toString();
+>.0?.toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+
+4e3?.toString();
+>4e3?.toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+
+1.e3?.toString();
+>1.e3?.toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+
+""?.toString();
+>""?.toString : Symbol(String.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(String.toString, Decl(lib.es5.d.ts, --, --))
+
+''?.toString();
+>''?.toString : Symbol(String.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(String.toString, Decl(lib.es5.d.ts, --, --))
+
+``?.toString();
+>``?.toString : Symbol(String.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(String.toString, Decl(lib.es5.d.ts, --, --))
+
+/./?.toString();
+>/./?.toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+
+/./g?.toString();
+>/./g?.toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+
+true?.toString();
+>true?.toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+
+false?.toString();
+>false?.toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+
+// templates
+`${x?.y}`;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// variables
+var v = x?.y;
+>v : Symbol(v, Decl(generalParsingOk.ts, 174, 3), Decl(generalParsingOk.ts, 175, 5), Decl(generalParsingOk.ts, 176, 5), Decl(generalParsingOk.ts, 177, 5), Decl(generalParsingOk.ts, 178, 5), Decl(generalParsingOk.ts, 179, 5))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+var [v] = x?.y;
+>v : Symbol(v, Decl(generalParsingOk.ts, 174, 3), Decl(generalParsingOk.ts, 175, 5), Decl(generalParsingOk.ts, 176, 5), Decl(generalParsingOk.ts, 177, 5), Decl(generalParsingOk.ts, 178, 5), Decl(generalParsingOk.ts, 179, 5))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+var [v = x?.y] = [1];
+>v : Symbol(v, Decl(generalParsingOk.ts, 174, 3), Decl(generalParsingOk.ts, 175, 5), Decl(generalParsingOk.ts, 176, 5), Decl(generalParsingOk.ts, 177, 5), Decl(generalParsingOk.ts, 178, 5), Decl(generalParsingOk.ts, 179, 5))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+var {v} = x?.y;
+>v : Symbol(v, Decl(generalParsingOk.ts, 174, 3), Decl(generalParsingOk.ts, 175, 5), Decl(generalParsingOk.ts, 176, 5), Decl(generalParsingOk.ts, 177, 5), Decl(generalParsingOk.ts, 178, 5), Decl(generalParsingOk.ts, 179, 5))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+var {v = x?.y} = {v:1};
+>v : Symbol(v, Decl(generalParsingOk.ts, 174, 3), Decl(generalParsingOk.ts, 175, 5), Decl(generalParsingOk.ts, 176, 5), Decl(generalParsingOk.ts, 177, 5), Decl(generalParsingOk.ts, 178, 5), Decl(generalParsingOk.ts, 179, 5))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>v : Symbol(v, Decl(generalParsingOk.ts, 178, 18))
+
+var {[x?.y]: v} = null;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>v : Symbol(v, Decl(generalParsingOk.ts, 174, 3), Decl(generalParsingOk.ts, 175, 5), Decl(generalParsingOk.ts, 176, 5), Decl(generalParsingOk.ts, 177, 5), Decl(generalParsingOk.ts, 178, 5), Decl(generalParsingOk.ts, 179, 5))
+
+// if/else if
+if (x?.y) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+if (1) {} else if (x?.y) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// switch
+switch (x?.y) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+switch (1) { case x?.y: break; }
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// do/while
+do {} while (x?.y)
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+while (x?.y) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// for
+for (x?.y; x?.y; x?.y);
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// for..in
+for (x?.y in {});
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// for..of
+for (x?.y of []);
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// enums
+enum E {
+>E : Symbol(E, Decl(generalParsingOk.ts, 200, 17))
+
+    a = x?.y
+>a : Symbol(E.a, Decl(generalParsingOk.ts, 203, 8))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+}
+
+=== tests/cases/conformance/emitter/es5/safeNavigation/exportsOk.ts ===
+export default x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+

tests/baselines/reference/emitter.safeNavigation.esnext.js

@@ -0,0 +1,697 @@
+//// [tests/cases/conformance/emitter/esnext/safeNavigation/emitter.safeNavigation.esnext.ts] ////
+
+//// [declarations.d.ts]
+declare var x: any;
+declare var y: any;
+declare var f: ({
+    (): void;
+    <T>(): void;
+    new (): any;
+    new <T>(): any;
+}) | undefined;
+declare var o: { y: typeof f; }
+declare class Base { x(): any; }
+declare namespace M {
+    export class y {}
+    export class z<T> {}
+}
+//// [propertyAccessOk.ts]
+x.y
+x?.y
+x?.y.z
+x.y?.z
+x?.y?.z
+//// [elementAccessOk.ts]
+x["y"]
+x?.["y"]
+x?.["y"]["z"]
+x["y"]?.["z"]
+x?.["y"]?.["z"]
+//// [callExpressionOk.ts]
+x()
+x?.()
+x.y?.()
+x["y"]?.()
+f?.<number>()
+o.y?.<number>()
+o["y"]?.<number>()
+//// [newExpressionOk.ts]
+new x()
+new x.y?.()
+new x["y"]?.()
+new f?.<number>()
+new o.y?.<number>()
+new o["y"]?.<number>()
+//// [mixedOk.ts]
+x?.y?.["z"]
+x?.["y"]?.z
+x?.y()
+x?.y?.()
+o?.y<number>()
+o?.y?.<number>()
+x?.["z"]()
+x?.["z"]?.()
+o?.["y"]<number>()
+o?.["y"]?.<number>()
+//// [mutationOk.ts]
+x?.y = 1
+x?.y += 1;
+x?.y -= 1;
+x?.y *= 1;
+x?.y /= 1;
+x?.y %= 1;
+x?.y **= 1;
+x?.y |= 1;
+x?.y &= 1;
+x?.y ^= 1;
+x?.y <<= 1;
+x?.y >>= 1;
+x?.y >>>= 1;
+x?.y++;
+x?.y--;
+++x?.y;
+--x?.y;
+delete x?.y;
+x?.["y"] = 1
+x?.["y"] += 1;
+x?.["y"] -= 1;
+x?.["y"] *= 1;
+x?.["y"] /= 1;
+x?.["y"] %= 1;
+x?.["y"] **= 1;
+x?.["y"] |= 1;
+x?.["y"] &= 1;
+x?.["y"] ^= 1;
+x?.["y"] <<= 1;
+x?.["y"] >>= 1;
+x?.["y"] >>>= 1;
+x?.["y"]++;
+x?.["y"]--;
+++x?.["y"];
+--x?.["y"];
+delete x?.["y"];
+//// [arrayAssignmentPatternOk.ts]
+[x?.y] = [1];
+[x?.["y"]] = [1];
+[...x?.y] = [1];
+[...x?.["y"]] = [1];
+//// [objectAssignmentPatternOk.ts]
+({ a: x?.y } = { a: 1 });
+({ a: x?.["y"] } = { a: 1 });
+//// [questionDotDigitIsConditionalOk.ts]
+x?.3:1;
+//// [superPropertyInvocationOk.ts]
+// supported for invocation of super property
+void class extends Base {
+    m() {
+        super.x?.();
+        super["x"]?.();
+    }
+}
+
+//// [generalParsingOk.ts]
+// object literals
+// - computed property names
+void { [x?.y]: 1 }
+void { [x?.["y"]]: 1 }
+void { [x?.()]: 1 }
+void { [new x?.()]: 1 }
+// - property assignments
+void { a: x?.y }
+void { a: x?.["y"] }
+void { a: x?.() }
+void { a: new x?.() }
+
+// classes
+// - computed property names
+// void class { [x?.y] = 1 }        // legal parse, but causes a checker error
+// void class { [x?.["y"]] = 1 }    // legal parse, but causes a checker error
+// void class { [x?.()] = 1 }       // legal parse, but causes a checker error
+// void class { [new f?.()] = 1 }   // legal parse, but causes a checker error
+void class { [Symbol?.toStringTag] = "" }
+// - property declarations
+void class { a = x?.y }
+void class { a = x?.["y"] }
+void class { a = x?.() }
+void class { a = new x?.() }
+// - heritage clauses
+void class extends M?.y {}
+void class extends M?.["y"] {}
+void class extends M?.z<number> {}
+// - class decorators
+@x?.y class C1 {}
+@x?.["y"] class C2 {}
+@x?.() class C3 {}
+@new x?.() class C4 {}
+// - member decorators
+class C5 { @x?.y m() {} }
+class C6 { @x?.["y"] m() {} } // allowed as ?.[ is not ambiguous with computed property names
+class C7 { @x?.() m() {} }
+class C8 { @new x?.() m () {} }
+// - parameter decorators
+class C9 { m(@x?.y a) {} }
+class C10 { m(@x?.["y"] a) {} }
+class C11 { m(@x?.() a) {} }
+class C12 { m(@new x?.() a) {} }
+
+// functions
+// - parameters
+void function (a = x?.y) {}
+void function (a = x?.["y"]) {}
+void function (a = x?.()) {}
+void function (a = new x?.()) {}
+// - binding elements
+//   - initializers
+void function ({ a = x?.y }) {}
+void function ({ a = x?.["y"] }) {}
+void function ({ a = x?.() }) {}
+void function ({ a = new x?.() }) {}
+//   - computed properties
+void function ({ [x?.y]: a }) {}
+void function ({ [x?.["y"]]: a }) {}
+void function ({ [x?.()]: a }) {}
+void function ({ [new x?.()]: a }) {}
+
+// arrow functions
+// - parameters
+((a = x?.y) => {});
+((a = x?.["y"]) => {});
+((a = x?.()) => {});
+((a = new x?.()) => {});
+// - expression bodies
+(() => x?.y);
+(() => x?.["y"]);
+(() => x?.());
+(() => new x?.());
+
+// parenthesis
+(x?.y);
+
+// comma
+x?.y, f();
+f(), x?.y;
+
+// conditional
+x?.y ? 0 : 1
+0 ? x?.y : 1;
+0 ? 1 : x?.y;
+
+// binary
+x?.y + 1;
+x?.y - 1;
+x?.y * 1;
+x?.y / 1;
+x?.y ** 1;
+x?.y % 1;
+x?.y ^ 1;
+x?.y & 1;
+x?.y | 1;
+x?.y << 1;
+x?.y >> 1;
+x?.y >>> 1;
+x?.y && 1;
+x?.y || 1;
+x?.y == 1;
+x?.y === 1;
+x?.y != 1;
+x?.y !== 1;
+x?.y < 1;
+x?.y <= 1;
+x?.y > 1;
+x?.y >= 1;
+1 + x?.y;
+1 - x?.y;
+1 * x?.y;
+1 / x?.y;
+1 ** x?.y;
+1 % x?.y;
+1 ^ x?.y;
+1 & x?.y;
+1 | x?.y;
+1 << x?.y;
+1 >> x?.y;
+1 >>> x?.y;
+1 && x?.y;
+1 || x?.y;
+1 == x?.y;
+1 === x?.y;
+1 != x?.y;
+1 !== x?.y;
+1 < x?.y;
+1 <= x?.y;
+1 > x?.y;
+1 >= x?.y;
+
+// prefix unary
++x?.y;
+-x?.y;
+!x?.y;
+~x?.y;
+
+// unary
+void x?.y;
+typeof x?.y;
+void function * () { yield x?.y; }
+void async function() { await x?.y; }
+
+// notnull
+x?.y!.z;
+
+// assertions
+<string>x?.y;
+x?.y as string;
+
+// array literals
+[x?.y];
+[, x?.y];
+[...x?.y];
+
+// literals
+1?.toString(); // no need for `..`
+1.?.toString();
+.0?.toString();
+4e3?.toString();
+1.e3?.toString();
+""?.toString();
+''?.toString();
+``?.toString();
+/./?.toString();
+/./g?.toString();
+true?.toString();
+false?.toString();
+
+// templates
+`${x?.y}`;
+
+// variables
+var v = x?.y;
+var [v] = x?.y;
+var [v = x?.y] = [1];
+var {v} = x?.y;
+var {v = x?.y} = {v:1};
+var {[x?.y]: v} = null;
+
+// if/else if
+if (x?.y) {}
+if (1) {} else if (x?.y) {}
+
+// switch
+switch (x?.y) {}
+switch (1) { case x?.y: break; }
+
+// do/while
+do {} while (x?.y)
+while (x?.y) {}
+
+// for
+for (x?.y; x?.y; x?.y);
+
+// for..in
+for (x?.y in {});
+
+// for..of
+for (x?.y of []);
+
+// enums
+enum E {
+    a = x?.y
+}
+
+//// [exportsOk.ts]
+export default x?.y;
+
+//// [propertyAccessOk.js]
+x.y;
+x?.y;
+x?.y.z;
+x.y?.z;
+x?.y?.z;
+//// [elementAccessOk.js]
+x["y"];
+x?.["y"];
+x?.["y"]["z"];
+x["y"]?.["z"];
+x?.["y"]?.["z"];
+//// [callExpressionOk.js]
+x();
+x?.();
+x.y?.();
+x["y"]?.();
+f?.();
+o.y?.();
+o["y"]?.();
+//// [newExpressionOk.js]
+new x();
+new x.y?.();
+new x["y"]?.();
+new f?.();
+new o.y?.();
+new o["y"]?.();
+//// [mixedOk.js]
+x?.y?.["z"];
+x?.["y"]?.z;
+x?.y();
+x?.y?.();
+o?.y();
+o?.y?.();
+x?.["z"]();
+x?.["z"]?.();
+o?.["y"]();
+o?.["y"]?.();
+//// [mutationOk.js]
+x?.y = 1;
+x?.y += 1;
+x?.y -= 1;
+x?.y *= 1;
+x?.y /= 1;
+x?.y %= 1;
+x?.y **= 1;
+x?.y |= 1;
+x?.y &= 1;
+x?.y ^= 1;
+x?.y <<= 1;
+x?.y >>= 1;
+x?.y >>>= 1;
+x?.y++;
+x?.y--;
+++x?.y;
+--x?.y;
+delete x?.y;
+x?.["y"] = 1;
+x?.["y"] += 1;
+x?.["y"] -= 1;
+x?.["y"] *= 1;
+x?.["y"] /= 1;
+x?.["y"] %= 1;
+x?.["y"] **= 1;
+x?.["y"] |= 1;
+x?.["y"] &= 1;
+x?.["y"] ^= 1;
+x?.["y"] <<= 1;
+x?.["y"] >>= 1;
+x?.["y"] >>>= 1;
+x?.["y"]++;
+x?.["y"]--;
+++x?.["y"];
+--x?.["y"];
+delete x?.["y"];
+//// [arrayAssignmentPatternOk.js]
+[x?.y] = [1];
+[x?.["y"]] = [1];
+[...x?.y] = [1];
+[...x?.["y"]] = [1];
+//// [objectAssignmentPatternOk.js]
+({ a: x?.y } = { a: 1 });
+({ a: x?.["y"] } = { a: 1 });
+//// [questionDotDigitIsConditionalOk.js]
+x ? .3 : 1;
+//// [superPropertyInvocationOk.js]
+// supported for invocation of super property
+void class extends Base {
+    m() {
+        super.x?.();
+        super["x"]?.();
+    }
+};
+//// [generalParsingOk.js]
+var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
+    var c = arguments.length, r = c < 3 ? target : desc === null ? desc = Object.getOwnPropertyDescriptor(target, key) : desc, d;
+    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") r = Reflect.decorate(decorators, target, key, desc);
+    else for (var i = decorators.length - 1; i >= 0; i--) if (d = decorators[i]) r = (c < 3 ? d(r) : c > 3 ? d(target, key, r) : d(target, key)) || r;
+    return c > 3 && r && Object.defineProperty(target, key, r), r;
+};
+var __param = (this && this.__param) || function (paramIndex, decorator) {
+    return function (target, key) { decorator(target, key, paramIndex); }
+};
+// object literals
+// - computed property names
+void { [x?.y]: 1 };
+void { [x?.["y"]]: 1 };
+void { [x?.()]: 1 };
+void { [new x?.()]: 1 };
+// - property assignments
+void { a: x?.y };
+void { a: x?.["y"] };
+void { a: x?.() };
+void { a: new x?.() };
+// classes
+// - computed property names
+// void class { [x?.y] = 1 }        // legal parse, but causes a checker error
+// void class { [x?.["y"]] = 1 }    // legal parse, but causes a checker error
+// void class { [x?.()] = 1 }       // legal parse, but causes a checker error
+// void class { [new f?.()] = 1 }   // legal parse, but causes a checker error
+void class {
+    constructor() {
+        this[Symbol?.toStringTag] = "";
+    }
+};
+// - property declarations
+void class {
+    constructor() {
+        this.a = x?.y;
+    }
+};
+void class {
+    constructor() {
+        this.a = x?.["y"];
+    }
+};
+void class {
+    constructor() {
+        this.a = x?.();
+    }
+};
+void class {
+    constructor() {
+        this.a = new x?.();
+    }
+};
+// - heritage clauses
+void class extends M?.y {
+};
+void class extends M?.["y"] {
+};
+void class extends M?.z {
+};
+// - class decorators
+let C1 = class C1 {
+};
+C1 = __decorate([
+    x?.y
+], C1);
+let C2 = class C2 {
+};
+C2 = __decorate([
+    x?.["y"]
+], C2);
+let C3 = class C3 {
+};
+C3 = __decorate([
+    x?.()
+], C3);
+let C4 = class C4 {
+};
+C4 = __decorate([
+    new x?.()
+], C4);
+// - member decorators
+class C5 {
+    m() { }
+}
+__decorate([
+    x?.y
+], C5.prototype, "m", null);
+class C6 {
+    m() { }
+} // allowed as ?.[ is not ambiguous with computed property names
+__decorate([
+    x?.["y"]
+], C6.prototype, "m", null);
+class C7 {
+    m() { }
+}
+__decorate([
+    x?.()
+], C7.prototype, "m", null);
+class C8 {
+    m() { }
+}
+__decorate([
+    new x?.()
+], C8.prototype, "m", null);
+// - parameter decorators
+class C9 {
+    m(a) { }
+}
+__decorate([
+    __param(0, x?.y)
+], C9.prototype, "m", null);
+class C10 {
+    m(a) { }
+}
+__decorate([
+    __param(0, x?.["y"])
+], C10.prototype, "m", null);
+class C11 {
+    m(a) { }
+}
+__decorate([
+    __param(0, x?.())
+], C11.prototype, "m", null);
+class C12 {
+    m(a) { }
+}
+__decorate([
+    __param(0, new x?.())
+], C12.prototype, "m", null);
+// functions
+// - parameters
+void function (a = x?.y) { };
+void function (a = x?.["y"]) { };
+void function (a = x?.()) { };
+void function (a = new x?.()) { };
+// - binding elements
+//   - initializers
+void function ({ a = x?.y }) { };
+void function ({ a = x?.["y"] }) { };
+void function ({ a = x?.() }) { };
+void function ({ a = new x?.() }) { };
+//   - computed properties
+void function ({ [x?.y]: a }) { };
+void function ({ [x?.["y"]]: a }) { };
+void function ({ [x?.()]: a }) { };
+void function ({ [new x?.()]: a }) { }((a = x?.y) => { });
+((a = x?.["y"]) => { });
+((a = x?.()) => { });
+((a = new x?.()) => { });
+// - expression bodies
+(() => x?.y);
+(() => x?.["y"]);
+(() => x?.());
+(() => new x?.());
+// parenthesis
+(x?.y);
+// comma
+x?.y, f();
+f(), x?.y;
+// conditional
+x?.y ? 0 : 1;
+0 ? x?.y : 1;
+0 ? 1 : x?.y;
+// binary
+x?.y + 1;
+x?.y - 1;
+x?.y * 1;
+x?.y / 1;
+x?.y ** 1;
+x?.y % 1;
+x?.y ^ 1;
+x?.y & 1;
+x?.y | 1;
+x?.y << 1;
+x?.y >> 1;
+x?.y >>> 1;
+x?.y && 1;
+x?.y || 1;
+x?.y == 1;
+x?.y === 1;
+x?.y != 1;
+x?.y !== 1;
+x?.y < 1;
+x?.y <= 1;
+x?.y > 1;
+x?.y >= 1;
+1 + x?.y;
+1 - x?.y;
+1 * x?.y;
+1 / x?.y;
+1 ** x?.y;
+1 % x?.y;
+1 ^ x?.y;
+1 & x?.y;
+1 | x?.y;
+1 << x?.y;
+1 >> x?.y;
+1 >>> x?.y;
+1 && x?.y;
+1 || x?.y;
+1 == x?.y;
+1 === x?.y;
+1 != x?.y;
+1 !== x?.y;
+1 < x?.y;
+1 <= x?.y;
+1 > x?.y;
+1 >= x?.y;
+// prefix unary
++x?.y;
+-x?.y;
+!x?.y;
+~x?.y;
+// unary
+void x?.y;
+typeof x?.y;
+void function* () { yield x?.y; };
+void async function () { await x?.y; };
+// notnull
+x?.y.z;
+// assertions
+x?.y;
+x?.y;
+// array literals
+[x?.y];
+[, x?.y];
+[...x?.y];
+// literals
+1?.toString(); // no need for `..`
+1.?.toString();
+.0?.toString();
+4e3?.toString();
+1.e3?.toString();
+""?.toString();
+''?.toString();
+``?.toString();
+/./?.toString();
+/./g?.toString();
+true?.toString();
+false?.toString();
+// templates
+`${x?.y}`;
+// variables
+var v = x?.y;
+var [v] = x?.y;
+var [v = x?.y] = [1];
+var { v } = x?.y;
+var { v = x?.y } = { v: 1 };
+var { [x?.y]: v } = null;
+// if/else if
+if (x?.y) { }
+if (1) { }
+else if (x?.y) { }
+// switch
+switch (x?.y) {
+}
+switch (1) {
+    case x?.y: break;
+}
+// do/while
+do { } while (x?.y);
+while (x?.y) { }
+// for
+for (x?.y; x?.y; x?.y)
+    ;
+// for..in
+for (x?.y in {})
+    ;
+// for..of
+for (x?.y of [])
+    ;
+// enums
+var E;
+(function (E) {
+    E[E["a"] = x?.y] = "a";
+})(E || (E = {}));
+//// [exportsOk.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.default = x?.y;

tests/baselines/reference/emitter.safeNavigation.esnext.symbols

@@ -0,0 +1,862 @@
+=== tests/cases/conformance/emitter/esnext/safeNavigation/declarations.d.ts ===
+declare var x: any;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+declare var y: any;
+>y : Symbol(y, Decl(declarations.d.ts, 1, 11))
+
+declare var f: ({
+>f : Symbol(f, Decl(declarations.d.ts, 2, 11))
+
+    (): void;
+    <T>(): void;
+>T : Symbol(T, Decl(declarations.d.ts, 4, 5))
+
+    new (): any;
+    new <T>(): any;
+>T : Symbol(T, Decl(declarations.d.ts, 6, 9))
+
+}) | undefined;
+declare var o: { y: typeof f; }
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+>f : Symbol(f, Decl(declarations.d.ts, 2, 11))
+
+declare class Base { x(): any; }
+>Base : Symbol(Base, Decl(declarations.d.ts, 8, 31))
+>x : Symbol(Base.x, Decl(declarations.d.ts, 9, 20))
+
+declare namespace M {
+>M : Symbol(M, Decl(declarations.d.ts, 9, 32))
+
+    export class y {}
+>y : Symbol(y, Decl(declarations.d.ts, 10, 21))
+
+    export class z<T> {}
+>z : Symbol(z, Decl(declarations.d.ts, 11, 21))
+>T : Symbol(T, Decl(declarations.d.ts, 12, 19))
+}
+=== tests/cases/conformance/emitter/esnext/safeNavigation/propertyAccessOk.ts ===
+x.y
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y.z
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x.y?.z
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y?.z
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+=== tests/cases/conformance/emitter/esnext/safeNavigation/elementAccessOk.ts ===
+x["y"]
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"]
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"]["z"]
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x["y"]?.["z"]
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"]?.["z"]
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+=== tests/cases/conformance/emitter/esnext/safeNavigation/callExpressionOk.ts ===
+x()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x.y?.()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x["y"]?.()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+f?.<number>()
+>f : Symbol(f, Decl(declarations.d.ts, 2, 11))
+
+o.y?.<number>()
+>o.y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+o["y"]?.<number>()
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>"y" : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+=== tests/cases/conformance/emitter/esnext/safeNavigation/newExpressionOk.ts ===
+new x()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+new x.y?.()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+new x["y"]?.()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+new f?.<number>()
+>f : Symbol(f, Decl(declarations.d.ts, 2, 11))
+
+new o.y?.<number>()
+>o.y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+new o["y"]?.<number>()
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>"y" : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+=== tests/cases/conformance/emitter/esnext/safeNavigation/mixedOk.ts ===
+x?.y?.["z"]
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"]?.z
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y?.()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+o?.y<number>()
+>o?.y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+o?.y?.<number>()
+>o?.y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>y : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+x?.["z"]()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["z"]?.()
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+o?.["y"]<number>()
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>"y" : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+o?.["y"]?.<number>()
+>o : Symbol(o, Decl(declarations.d.ts, 8, 11))
+>"y" : Symbol(y, Decl(declarations.d.ts, 8, 16))
+
+=== tests/cases/conformance/emitter/esnext/safeNavigation/mutationOk.ts ===
+x?.y = 1
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y += 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y -= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y *= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y /= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y %= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y **= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y |= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y &= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y ^= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y <<= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y >>= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y >>>= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y++;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y--;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+++x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+--x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+delete x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] = 1
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] += 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] -= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] *= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] /= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] %= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] **= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] |= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] &= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] ^= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] <<= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] >>= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"] >>>= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"]++;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.["y"]--;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+++x?.["y"];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+--x?.["y"];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+delete x?.["y"];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+=== tests/cases/conformance/emitter/esnext/safeNavigation/arrayAssignmentPatternOk.ts ===
+[x?.y] = [1];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+[x?.["y"]] = [1];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+[...x?.y] = [1];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+[...x?.["y"]] = [1];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+=== tests/cases/conformance/emitter/esnext/safeNavigation/objectAssignmentPatternOk.ts ===
+({ a: x?.y } = { a: 1 });
+>a : Symbol(a, Decl(objectAssignmentPatternOk.ts, 0, 2))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(objectAssignmentPatternOk.ts, 0, 16))
+
+({ a: x?.["y"] } = { a: 1 });
+>a : Symbol(a, Decl(objectAssignmentPatternOk.ts, 1, 2))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(objectAssignmentPatternOk.ts, 1, 20))
+
+=== tests/cases/conformance/emitter/esnext/safeNavigation/questionDotDigitIsConditionalOk.ts ===
+x?.3:1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+=== tests/cases/conformance/emitter/esnext/safeNavigation/superPropertyInvocationOk.ts ===
+// supported for invocation of super property
+void class extends Base {
+>Base : Symbol(Base, Decl(declarations.d.ts, 8, 31))
+
+    m() {
+>m : Symbol((Anonymous class).m, Decl(superPropertyInvocationOk.ts, 1, 25))
+
+        super.x?.();
+>super.x : Symbol(Base.x, Decl(declarations.d.ts, 9, 20))
+>super : Symbol(Base, Decl(declarations.d.ts, 8, 31))
+>x : Symbol(Base.x, Decl(declarations.d.ts, 9, 20))
+
+        super["x"]?.();
+>super : Symbol(Base, Decl(declarations.d.ts, 8, 31))
+>"x" : Symbol(Base.x, Decl(declarations.d.ts, 9, 20))
+    }
+}
+
+=== tests/cases/conformance/emitter/esnext/safeNavigation/generalParsingOk.ts ===
+// object literals
+// - computed property names
+void { [x?.y]: 1 }
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void { [x?.["y"]]: 1 }
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void { [x?.()]: 1 }
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void { [new x?.()]: 1 }
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// - property assignments
+void { a: x?.y }
+>a : Symbol(a, Decl(generalParsingOk.ts, 7, 6))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void { a: x?.["y"] }
+>a : Symbol(a, Decl(generalParsingOk.ts, 8, 6))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void { a: x?.() }
+>a : Symbol(a, Decl(generalParsingOk.ts, 9, 6))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void { a: new x?.() }
+>a : Symbol(a, Decl(generalParsingOk.ts, 10, 6))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// classes
+// - computed property names
+// void class { [x?.y] = 1 }        // legal parse, but causes a checker error
+// void class { [x?.["y"]] = 1 }    // legal parse, but causes a checker error
+// void class { [x?.()] = 1 }       // legal parse, but causes a checker error
+// void class { [new f?.()] = 1 }   // legal parse, but causes a checker error
+void class { [Symbol?.toStringTag] = "" }
+>Symbol?.toStringTag : Symbol(SymbolConstructor.toStringTag, Decl(lib.es2015.symbol.wellknown.d.ts, --, --))
+>Symbol : Symbol(Symbol, Decl(lib.es2015.symbol.wellknown.d.ts, --, --), Decl(lib.es2015.symbol.d.ts, --, --), Decl(lib.es2015.symbol.d.ts, --, --))
+>toStringTag : Symbol(SymbolConstructor.toStringTag, Decl(lib.es2015.symbol.wellknown.d.ts, --, --))
+
+// - property declarations
+void class { a = x?.y }
+>a : Symbol((Anonymous class).a, Decl(generalParsingOk.ts, 20, 12))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void class { a = x?.["y"] }
+>a : Symbol((Anonymous class).a, Decl(generalParsingOk.ts, 21, 12))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void class { a = x?.() }
+>a : Symbol((Anonymous class).a, Decl(generalParsingOk.ts, 22, 12))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void class { a = new x?.() }
+>a : Symbol((Anonymous class).a, Decl(generalParsingOk.ts, 23, 12))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// - heritage clauses
+void class extends M?.y {}
+>M?.y : Symbol(M.y, Decl(declarations.d.ts, 10, 21))
+>M : Symbol(M, Decl(declarations.d.ts, 9, 32))
+>y : Symbol(M.y, Decl(declarations.d.ts, 10, 21))
+
+void class extends M?.["y"] {}
+>M : Symbol(M, Decl(declarations.d.ts, 9, 32))
+>"y" : Symbol(M.y, Decl(declarations.d.ts, 10, 21))
+
+void class extends M?.z<number> {}
+>M?.z : Symbol(M.z, Decl(declarations.d.ts, 11, 21))
+>M : Symbol(M, Decl(declarations.d.ts, 9, 32))
+>z : Symbol(M.z, Decl(declarations.d.ts, 11, 21))
+
+// - class decorators
+@x?.y class C1 {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>C1 : Symbol(C1, Decl(generalParsingOk.ts, 27, 34))
+
+@x?.["y"] class C2 {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>C2 : Symbol(C2, Decl(generalParsingOk.ts, 29, 17))
+
+@x?.() class C3 {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>C3 : Symbol(C3, Decl(generalParsingOk.ts, 30, 21))
+
+@new x?.() class C4 {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>C4 : Symbol(C4, Decl(generalParsingOk.ts, 31, 18))
+
+// - member decorators
+class C5 { @x?.y m() {} }
+>C5 : Symbol(C5, Decl(generalParsingOk.ts, 32, 22))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>m : Symbol(C5.m, Decl(generalParsingOk.ts, 34, 10))
+
+class C6 { @x?.["y"] m() {} } // allowed as ?.[ is not ambiguous with computed property names
+>C6 : Symbol(C6, Decl(generalParsingOk.ts, 34, 25))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>m : Symbol(C6.m, Decl(generalParsingOk.ts, 35, 10))
+
+class C7 { @x?.() m() {} }
+>C7 : Symbol(C7, Decl(generalParsingOk.ts, 35, 29))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>m : Symbol(C7.m, Decl(generalParsingOk.ts, 36, 10))
+
+class C8 { @new x?.() m () {} }
+>C8 : Symbol(C8, Decl(generalParsingOk.ts, 36, 26))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>m : Symbol(C8.m, Decl(generalParsingOk.ts, 37, 10))
+
+// - parameter decorators
+class C9 { m(@x?.y a) {} }
+>C9 : Symbol(C9, Decl(generalParsingOk.ts, 37, 31))
+>m : Symbol(C9.m, Decl(generalParsingOk.ts, 39, 10))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 39, 13))
+
+class C10 { m(@x?.["y"] a) {} }
+>C10 : Symbol(C10, Decl(generalParsingOk.ts, 39, 26))
+>m : Symbol(C10.m, Decl(generalParsingOk.ts, 40, 11))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 40, 14))
+
+class C11 { m(@x?.() a) {} }
+>C11 : Symbol(C11, Decl(generalParsingOk.ts, 40, 31))
+>m : Symbol(C11.m, Decl(generalParsingOk.ts, 41, 11))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 41, 14))
+
+class C12 { m(@new x?.() a) {} }
+>C12 : Symbol(C12, Decl(generalParsingOk.ts, 41, 28))
+>m : Symbol(C12.m, Decl(generalParsingOk.ts, 42, 11))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 42, 14))
+
+// functions
+// - parameters
+void function (a = x?.y) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 46, 15))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void function (a = x?.["y"]) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 47, 15))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void function (a = x?.()) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 48, 15))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void function (a = new x?.()) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 49, 15))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// - binding elements
+//   - initializers
+void function ({ a = x?.y }) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 52, 16))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void function ({ a = x?.["y"] }) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 53, 16))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void function ({ a = x?.() }) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 54, 16))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void function ({ a = new x?.() }) {}
+>a : Symbol(a, Decl(generalParsingOk.ts, 55, 16))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+//   - computed properties
+void function ({ [x?.y]: a }) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 57, 16))
+
+void function ({ [x?.["y"]]: a }) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 58, 16))
+
+void function ({ [x?.()]: a }) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 59, 16))
+
+void function ({ [new x?.()]: a }) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>a : Symbol(a, Decl(generalParsingOk.ts, 60, 16))
+
+// arrow functions
+// - parameters
+((a = x?.y) => {});
+>a : Symbol(a, Decl(generalParsingOk.ts, 64, 2))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+((a = x?.["y"]) => {});
+>a : Symbol(a, Decl(generalParsingOk.ts, 65, 2))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+((a = x?.()) => {});
+>a : Symbol(a, Decl(generalParsingOk.ts, 66, 2))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+((a = new x?.()) => {});
+>a : Symbol(a, Decl(generalParsingOk.ts, 67, 2))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// - expression bodies
+(() => x?.y);
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+(() => x?.["y"]);
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+(() => x?.());
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+(() => new x?.());
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// parenthesis
+(x?.y);
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// comma
+x?.y, f();
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>f : Symbol(f, Decl(declarations.d.ts, 2, 11))
+
+f(), x?.y;
+>f : Symbol(f, Decl(declarations.d.ts, 2, 11))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// conditional
+x?.y ? 0 : 1
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+0 ? x?.y : 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+0 ? 1 : x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// binary
+x?.y + 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y - 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y * 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y / 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y ** 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y % 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y ^ 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y & 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y | 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y << 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y >> 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y >>> 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y && 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y || 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y == 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y === 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y != 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y !== 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y < 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y <= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y > 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y >= 1;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 + x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 - x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 * x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 / x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 ** x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 % x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 ^ x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 & x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 | x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 << x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 >> x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 >>> x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 && x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 || x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 == x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 === x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 != x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 !== x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 < x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 <= x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 > x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+1 >= x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// prefix unary
++x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+-x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+!x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+~x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// unary
+void x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+typeof x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void function * () { yield x?.y; }
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+void async function() { await x?.y; }
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// notnull
+x?.y!.z;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// assertions
+<string>x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+x?.y as string;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// array literals
+[x?.y];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+[, x?.y];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+[...x?.y];
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// literals
+1?.toString(); // no need for `..`
+>1?.toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+
+1.?.toString();
+>1.?.toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+
+.0?.toString();
+>.0?.toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+
+4e3?.toString();
+>4e3?.toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+
+1.e3?.toString();
+>1.e3?.toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+
+""?.toString();
+>""?.toString : Symbol(String.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(String.toString, Decl(lib.es5.d.ts, --, --))
+
+''?.toString();
+>''?.toString : Symbol(String.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(String.toString, Decl(lib.es5.d.ts, --, --))
+
+``?.toString();
+>``?.toString : Symbol(String.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(String.toString, Decl(lib.es5.d.ts, --, --))
+
+/./?.toString();
+>/./?.toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+
+/./g?.toString();
+>/./g?.toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+
+true?.toString();
+>true?.toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+
+false?.toString();
+>false?.toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+>toString : Symbol(Object.toString, Decl(lib.es5.d.ts, --, --))
+
+// templates
+`${x?.y}`;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// variables
+var v = x?.y;
+>v : Symbol(v, Decl(generalParsingOk.ts, 174, 3), Decl(generalParsingOk.ts, 175, 5), Decl(generalParsingOk.ts, 176, 5), Decl(generalParsingOk.ts, 177, 5), Decl(generalParsingOk.ts, 178, 5), Decl(generalParsingOk.ts, 179, 5))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+var [v] = x?.y;
+>v : Symbol(v, Decl(generalParsingOk.ts, 174, 3), Decl(generalParsingOk.ts, 175, 5), Decl(generalParsingOk.ts, 176, 5), Decl(generalParsingOk.ts, 177, 5), Decl(generalParsingOk.ts, 178, 5), Decl(generalParsingOk.ts, 179, 5))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+var [v = x?.y] = [1];
+>v : Symbol(v, Decl(generalParsingOk.ts, 174, 3), Decl(generalParsingOk.ts, 175, 5), Decl(generalParsingOk.ts, 176, 5), Decl(generalParsingOk.ts, 177, 5), Decl(generalParsingOk.ts, 178, 5), Decl(generalParsingOk.ts, 179, 5))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+var {v} = x?.y;
+>v : Symbol(v, Decl(generalParsingOk.ts, 174, 3), Decl(generalParsingOk.ts, 175, 5), Decl(generalParsingOk.ts, 176, 5), Decl(generalParsingOk.ts, 177, 5), Decl(generalParsingOk.ts, 178, 5), Decl(generalParsingOk.ts, 179, 5))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+var {v = x?.y} = {v:1};
+>v : Symbol(v, Decl(generalParsingOk.ts, 174, 3), Decl(generalParsingOk.ts, 175, 5), Decl(generalParsingOk.ts, 176, 5), Decl(generalParsingOk.ts, 177, 5), Decl(generalParsingOk.ts, 178, 5), Decl(generalParsingOk.ts, 179, 5))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>v : Symbol(v, Decl(generalParsingOk.ts, 178, 18))
+
+var {[x?.y]: v} = null;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>v : Symbol(v, Decl(generalParsingOk.ts, 174, 3), Decl(generalParsingOk.ts, 175, 5), Decl(generalParsingOk.ts, 176, 5), Decl(generalParsingOk.ts, 177, 5), Decl(generalParsingOk.ts, 178, 5), Decl(generalParsingOk.ts, 179, 5))
+
+// if/else if
+if (x?.y) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+if (1) {} else if (x?.y) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// switch
+switch (x?.y) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+switch (1) { case x?.y: break; }
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// do/while
+do {} while (x?.y)
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+while (x?.y) {}
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// for
+for (x?.y; x?.y; x?.y);
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// for..in
+for (x?.y in {});
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// for..of
+for (x?.y of []);
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+
+// enums
+enum E {
+>E : Symbol(E, Decl(generalParsingOk.ts, 200, 17))
+
+    a = x?.y
+>a : Symbol(E.a, Decl(generalParsingOk.ts, 203, 8))
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+}
+
+=== tests/cases/conformance/emitter/esnext/safeNavigation/exportsOk.ts ===
+export default x?.y;
+>x : Symbol(x, Decl(declarations.d.ts, 0, 11))
+

tests/baselines/reference/parser.safeNavigation.esnext.errors.txt

@@ -0,0 +1,383 @@
+tests/cases/conformance/parser/ecmascriptnext/safeNavigation/metaPropertyError.ts(4,12): error TS1109: Expression expected.
+tests/cases/conformance/parser/ecmascriptnext/safeNavigation/missingIdentifierError.ts(1,4): error TS1003: Identifier expected.
+tests/cases/conformance/parser/ecmascriptnext/safeNavigation/spaceInTokenError.ts(1,4): error TS1109: Expression expected.
+tests/cases/conformance/parser/ecmascriptnext/safeNavigation/spaceInTokenError.ts(1,6): error TS1005: ':' expected.
+tests/cases/conformance/parser/ecmascriptnext/safeNavigation/superError.ts(4,14): error TS1012: Unexpected token.
+tests/cases/conformance/parser/ecmascriptnext/safeNavigation/superProperty1Error.ts(4,14): error TS1005: '.' expected.
+tests/cases/conformance/parser/ecmascriptnext/safeNavigation/superProperty2Error.ts(4,14): error TS1012: Unexpected token.
+tests/cases/conformance/parser/ecmascriptnext/safeNavigation/taggedTemplateError.ts(2,4): error TS1003: Identifier expected.
+tests/cases/conformance/parser/ecmascriptnext/safeNavigation/taggedTemplateError.ts(2,10): error TS2304: Cannot find name 'bar'.
+
+
+==== tests/cases/conformance/parser/ecmascriptnext/safeNavigation/declarations.d.ts (0 errors) ====
+    declare var x: any;
+    declare var y: any;
+    declare var f: ({
+        (): void;
+        <T>(): void;
+        new (): any;
+        new <T>(): any;
+    }) | undefined;
+    declare var o: { y: typeof f; }
+    declare class Base { x: any; }
+    declare namespace M {
+        export class y {}
+        export class z<T> {}
+    }
+==== tests/cases/conformance/parser/ecmascriptnext/safeNavigation/propertyAccessOk.ts (0 errors) ====
+    x.y
+    x?.y
+    x?.y.z
+    x.y?.z
+    x?.y?.z
+==== tests/cases/conformance/parser/ecmascriptnext/safeNavigation/elementAccessOk.ts (0 errors) ====
+    x["y"]
+    x?.["y"]
+    x?.["y"]["z"]
+    x["y"]?.["z"]
+    x?.["y"]?.["z"]
+==== tests/cases/conformance/parser/ecmascriptnext/safeNavigation/callExpressionOk.ts (0 errors) ====
+    x()
+    x?.()
+    x.y?.()
+    x["y"]?.()
+    f?.<number>()
+    o.y?.<number>()
+    o["y"]?.<number>()
+==== tests/cases/conformance/parser/ecmascriptnext/safeNavigation/newExpressionOk.ts (0 errors) ====
+    new x()
+    new x.y?.()
+    new x["y"]?.()
+    new f?.<number>()
+    new o.y?.<number>()
+    new o["y"]?.<number>()
+==== tests/cases/conformance/parser/ecmascriptnext/safeNavigation/mixedOk.ts (0 errors) ====
+    x?.y?.["z"]
+    x?.["y"]?.z
+    x?.y()
+    x?.y?.()
+    o?.y<number>()
+    o?.y?.<number>()
+    x?.["z"]()
+    x?.["z"]?.()
+    o?.["y"]<number>()
+    o?.["y"]?.<number>()
+==== tests/cases/conformance/parser/ecmascriptnext/safeNavigation/mutationOk.ts (0 errors) ====
+    x?.y = 1
+    x?.y += 1;
+    x?.y -= 1;
+    x?.y *= 1;
+    x?.y /= 1;
+    x?.y %= 1;
+    x?.y **= 1;
+    x?.y |= 1;
+    x?.y &= 1;
+    x?.y ^= 1;
+    x?.y <<= 1;
+    x?.y >>= 1;
+    x?.y >>>= 1;
+    x?.y++;
+    x?.y--;
+    ++x?.y;
+    --x?.y;
+    delete x?.y;
+    x?.["y"] = 1
+    x?.["y"] += 1;
+    x?.["y"] -= 1;
+    x?.["y"] *= 1;
+    x?.["y"] /= 1;
+    x?.["y"] %= 1;
+    x?.["y"] **= 1;
+    x?.["y"] |= 1;
+    x?.["y"] &= 1;
+    x?.["y"] ^= 1;
+    x?.["y"] <<= 1;
+    x?.["y"] >>= 1;
+    x?.["y"] >>>= 1;
+    x?.["y"]++;
+    x?.["y"]--;
+    ++x?.["y"];
+    --x?.["y"];
+    delete x?.["y"];
+==== tests/cases/conformance/parser/ecmascriptnext/safeNavigation/arrayAssignmentPatternOk.ts (0 errors) ====
+    [x?.y] = [1];
+    [x?.["y"]] = [1];
+    [...x?.y] = [1];
+    [...x?.["y"]] = [1];
+==== tests/cases/conformance/parser/ecmascriptnext/safeNavigation/objectAssignmentPatternOk.ts (0 errors) ====
+    ({ a: x?.y } = { a: 1 });
+    ({ a: x?.["y"] } = { a: 1 });
+==== tests/cases/conformance/parser/ecmascriptnext/safeNavigation/questionDotDigitIsConditionalOk.ts (0 errors) ====
+    x?.3:1;
+==== tests/cases/conformance/parser/ecmascriptnext/safeNavigation/spaceInTokenError.ts (2 errors) ====
+    x? .y
+       ~
+!!! error TS1109: Expression expected.
+         
+!!! error TS1005: ':' expected.
+==== tests/cases/conformance/parser/ecmascriptnext/safeNavigation/missingIdentifierError.ts (1 errors) ====
+    x?.
+       
+!!! error TS1003: Identifier expected.
+==== tests/cases/conformance/parser/ecmascriptnext/safeNavigation/taggedTemplateError.ts (2 errors) ====
+    // not supported for tagged templates
+    x?.`foo${bar}`
+       ~~~~~~
+!!! error TS1003: Identifier expected.
+             ~~~
+!!! error TS2304: Cannot find name 'bar'.
+==== tests/cases/conformance/parser/ecmascriptnext/safeNavigation/superError.ts (1 errors) ====
+    // not supported for super
+    void class extends Base {
+        constructor() {
+            super?.();
+                 ~~
+!!! error TS1012: Unexpected token.
+        }
+    }
+==== tests/cases/conformance/parser/ecmascriptnext/safeNavigation/superProperty1Error.ts (1 errors) ====
+    // not supported for super property
+    void class extends Base {
+        m() {
+            super?.x;
+                 ~~
+!!! error TS1005: '.' expected.
+        }
+    }
+==== tests/cases/conformance/parser/ecmascriptnext/safeNavigation/superProperty2Error.ts (1 errors) ====
+    // not supported for super property
+    void class extends Base {
+        m() {
+            super?.["x"];
+                 ~~
+!!! error TS1012: Unexpected token.
+        }
+    }
+==== tests/cases/conformance/parser/ecmascriptnext/safeNavigation/superPropertyInvocationOk.ts (0 errors) ====
+    // supported for invocation of super property
+    void class extends Base {
+        m() {
+            super.x?.();
+            super["x"]?.();
+        }
+    }
+==== tests/cases/conformance/parser/ecmascriptnext/safeNavigation/metaPropertyError.ts (1 errors) ====
+    // not supported for meta property
+    void class {
+        constructor() {
+            new?.target;
+               ~~
+!!! error TS1109: Expression expected.
+        }
+    }
+    
+==== tests/cases/conformance/parser/ecmascriptnext/safeNavigation/generalParsingOk.ts (0 errors) ====
+    // object literals
+    // - computed property names
+    void { [x?.y]: 1 }
+    void { [x?.["y"]]: 1 }
+    void { [x?.()]: 1 }
+    void { [new x?.()]: 1 }
+    // - property assignments
+    void { a: x?.y }
+    void { a: x?.["y"] }
+    void { a: x?.() }
+    void { a: new x?.() }
+    
+    // classes
+    // - computed property names
+    // void class { [x?.y] = 1 }        // legal parse, but causes a checker error
+    // void class { [x?.["y"]] = 1 }    // legal parse, but causes a checker error
+    // void class { [x?.()] = 1 }       // legal parse, but causes a checker error
+    // void class { [new f?.()] = 1 }   // legal parse, but causes a checker error
+    void class { [Symbol?.toStringTag] = "" }
+    // - property declarations
+    void class { a = x?.y }
+    void class { a = x?.["y"] }
+    void class { a = x?.() }
+    void class { a = new x?.() }
+    // - heritage clauses
+    void class extends M?.y {}
+    void class extends M?.["y"] {}
+    void class extends M?.z<number> {}
+    // - class decorators
+    @x?.y class C1 {}
+    @x?.["y"] class C2 {}
+    @x?.() class C3 {}
+    @new x?.() class C4 {}
+    // - member decorators
+    class C5 { @x?.y m() {} }
+    class C6 { @x?.["y"] m() {} } // allowed as ?.[ is not ambiguous with computed property names
+    class C7 { @x?.() m() {} }
+    class C8 { @new x?.() m () {} }
+    // - parameter decorators
+    class C9 { m(@x?.y a) {} }
+    class C10 { m(@x?.["y"] a) {} }
+    class C11 { m(@x?.() a) {} }
+    class C12 { m(@new x?.() a) {} }
+    
+    // functions
+    // - parameters
+    void function (a = x?.y) {}
+    void function (a = x?.["y"]) {}
+    void function (a = x?.()) {}
+    void function (a = new x?.()) {}
+    // - binding elements
+    //   - initializers
+    void function ({ a = x?.y }) {}
+    void function ({ a = x?.["y"] }) {}
+    void function ({ a = x?.() }) {}
+    void function ({ a = new x?.() }) {}
+    //   - computed properties
+    void function ({ [x?.y]: a }) {}
+    void function ({ [x?.["y"]]: a }) {}
+    void function ({ [x?.()]: a }) {}
+    void function ({ [new x?.()]: a }) {}
+    
+    // arrow functions
+    // - parameters
+    ((a = x?.y) => {});
+    ((a = x?.["y"]) => {});
+    ((a = x?.()) => {});
+    ((a = new x?.()) => {});
+    // - expression bodies
+    (() => x?.y);
+    (() => x?.["y"]);
+    (() => x?.());
+    (() => new x?.());
+    
+    // parenthesis
+    (x?.y);
+    
+    // comma
+    x?.y, f();
+    f(), x?.y;
+    
+    // conditional
+    x?.y ? 0 : 1
+    0 ? x?.y : 1;
+    0 ? 1 : x?.y;
+    
+    // binary
+    x?.y + 1;
+    x?.y - 1;
+    x?.y * 1;
+    x?.y / 1;
+    x?.y ** 1;
+    x?.y % 1;
+    x?.y ^ 1;
+    x?.y & 1;
+    x?.y | 1;
+    x?.y << 1;
+    x?.y >> 1;
+    x?.y >>> 1;
+    x?.y && 1;
+    x?.y || 1;
+    x?.y == 1;
+    x?.y === 1;
+    x?.y != 1;
+    x?.y !== 1;
+    x?.y < 1;
+    x?.y <= 1;
+    x?.y > 1;
+    x?.y >= 1;
+    1 + x?.y;
+    1 - x?.y;
+    1 * x?.y;
+    1 / x?.y;
+    1 ** x?.y;
+    1 % x?.y;
+    1 ^ x?.y;
+    1 & x?.y;
+    1 | x?.y;
+    1 << x?.y;
+    1 >> x?.y;
+    1 >>> x?.y;
+    1 && x?.y;
+    1 || x?.y;
+    1 == x?.y;
+    1 === x?.y;
+    1 != x?.y;
+    1 !== x?.y;
+    1 < x?.y;
+    1 <= x?.y;
+    1 > x?.y;
+    1 >= x?.y;
+    
+    // prefix unary
+    +x?.y;
+    -x?.y;
+    !x?.y;
+    ~x?.y;
+    
+    // unary
+    void x?.y;
+    typeof x?.y;
+    void function * () { yield x?.y; }
+    void async function() { await x?.y; }
+    
+    // notnull
+    x?.y!.z;
+    
+    // assertions
+    <string>x?.y;
+    x?.y as string;
+    
+    // array literals
+    [x?.y];
+    [, x?.y];
+    [...x?.y];
+    
+    // literals
+    1?.toString(); // no need for `..`
+    1.?.toString();
+    .0?.toString();
+    4e3?.toString();
+    1.e3?.toString();
+    ""?.toString();
+    ''?.toString();
+    ``?.toString();
+    /./?.toString();
+    /./g?.toString();
+    true?.toString();
+    false?.toString();
+    
+    // templates
+    `${x?.y}`;
+    
+    // variables
+    var v = x?.y;
+    var [v] = x?.y;
+    var [v = x?.y] = [1];
+    var {v} = x?.y;
+    var {v = x?.y} = {v:1};
+    var {[x?.y]: v} = null;
+    
+    // if/else if
+    if (x?.y) {}
+    if (1) {} else if (x?.y) {}
+    
+    // switch
+    switch (x?.y) {}
+    switch (1) { case x?.y: break; }
+    
+    // do/while
+    do {} while (x?.y)
+    while (x?.y) {}
+    
+    // for
+    for (x?.y; x?.y; x?.y);
+    
+    // for..in
+    for (x?.y in {});
+    
+    // for..of
+    for (x?.y of []);
+    
+    // enums
+    enum E {
+        a = x?.y
+    }
+    
+==== tests/cases/conformance/parser/ecmascriptnext/safeNavigation/exportsOk.ts (0 errors) ====
+    export default x?.y;

tests/baselines/reference/types.safeNavigation.esnext.1.symbols

@@ -0,0 +1,144 @@
+=== tests/cases/conformance/types/safeNavigation/types.safeNavigation.esnext.1.ts ===
+declare const x1: (() => number) | undefined | null;
+>x1 : Symbol(x1, Decl(types.safeNavigation.esnext.1.ts, 0, 13))
+
+declare const x2: { y: (() => number) | undefined | null; };
+>x2 : Symbol(x2, Decl(types.safeNavigation.esnext.1.ts, 1, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 1, 19))
+
+declare const x3: { y: (() => number) | undefined | null; } | undefined | null;
+>x3 : Symbol(x3, Decl(types.safeNavigation.esnext.1.ts, 2, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 2, 19))
+
+declare const x4: { y: { z: (() => number) | undefined | null; } };
+>x4 : Symbol(x4, Decl(types.safeNavigation.esnext.1.ts, 3, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 3, 19))
+>z : Symbol(z, Decl(types.safeNavigation.esnext.1.ts, 3, 24))
+
+declare const x5: { y: { z: (() => number) | undefined | null; } | undefined | null } | undefined | null;
+>x5 : Symbol(x5, Decl(types.safeNavigation.esnext.1.ts, 4, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 4, 19))
+>z : Symbol(z, Decl(types.safeNavigation.esnext.1.ts, 4, 24))
+
+declare const x6: { y: number } | undefined | null;
+>x6 : Symbol(x6, Decl(types.safeNavigation.esnext.1.ts, 5, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 5, 19))
+
+declare const x7: { y: any };
+>x7 : Symbol(x7, Decl(types.safeNavigation.esnext.1.ts, 6, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 6, 19))
+
+declare const x8: { y: { z: number } | undefined | null } | undefined | null;
+>x8 : Symbol(x8, Decl(types.safeNavigation.esnext.1.ts, 7, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 7, 19))
+>z : Symbol(z, Decl(types.safeNavigation.esnext.1.ts, 7, 24))
+
+declare const y: "y";
+>y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 8, 13))
+
+declare const z: "z";
+>z : Symbol(z, Decl(types.safeNavigation.esnext.1.ts, 9, 13))
+
+x1?.();
+>x1 : Symbol(x1, Decl(types.safeNavigation.esnext.1.ts, 0, 13))
+
+(x1)?.();
+>x1 : Symbol(x1, Decl(types.safeNavigation.esnext.1.ts, 0, 13))
+
+x2.y?.();
+>x2.y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 1, 19))
+>x2 : Symbol(x2, Decl(types.safeNavigation.esnext.1.ts, 1, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 1, 19))
+
+x2[y]?.();
+>x2 : Symbol(x2, Decl(types.safeNavigation.esnext.1.ts, 1, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 8, 13))
+
+(x2.y)?.();
+>x2.y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 1, 19))
+>x2 : Symbol(x2, Decl(types.safeNavigation.esnext.1.ts, 1, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 1, 19))
+
+(x2[y])?.();
+>x2 : Symbol(x2, Decl(types.safeNavigation.esnext.1.ts, 1, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 8, 13))
+
+x3?.y?.();
+>x3?.y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 2, 19))
+>x3 : Symbol(x3, Decl(types.safeNavigation.esnext.1.ts, 2, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 2, 19))
+
+x3?.[y]?.();
+>x3 : Symbol(x3, Decl(types.safeNavigation.esnext.1.ts, 2, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 8, 13))
+
+x4.y.z?.();
+>x4.y.z : Symbol(z, Decl(types.safeNavigation.esnext.1.ts, 3, 24))
+>x4.y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 3, 19))
+>x4 : Symbol(x4, Decl(types.safeNavigation.esnext.1.ts, 3, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 3, 19))
+>z : Symbol(z, Decl(types.safeNavigation.esnext.1.ts, 3, 24))
+
+x4.y[z]?.();
+>x4.y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 3, 19))
+>x4 : Symbol(x4, Decl(types.safeNavigation.esnext.1.ts, 3, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 3, 19))
+>z : Symbol(z, Decl(types.safeNavigation.esnext.1.ts, 9, 13))
+
+(x4.y.z)?.();
+>x4.y.z : Symbol(z, Decl(types.safeNavigation.esnext.1.ts, 3, 24))
+>x4.y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 3, 19))
+>x4 : Symbol(x4, Decl(types.safeNavigation.esnext.1.ts, 3, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 3, 19))
+>z : Symbol(z, Decl(types.safeNavigation.esnext.1.ts, 3, 24))
+
+(x4.y[z])?.();
+>x4.y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 3, 19))
+>x4 : Symbol(x4, Decl(types.safeNavigation.esnext.1.ts, 3, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 3, 19))
+>z : Symbol(z, Decl(types.safeNavigation.esnext.1.ts, 9, 13))
+
+x5?.y?.z?.();
+>x5?.y?.z : Symbol(z, Decl(types.safeNavigation.esnext.1.ts, 4, 24))
+>x5?.y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 4, 19))
+>x5 : Symbol(x5, Decl(types.safeNavigation.esnext.1.ts, 4, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 4, 19))
+>z : Symbol(z, Decl(types.safeNavigation.esnext.1.ts, 4, 24))
+
+x5?.y?.z;
+>x5?.y?.z : Symbol(z, Decl(types.safeNavigation.esnext.1.ts, 4, 24))
+>x5?.y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 4, 19))
+>x5 : Symbol(x5, Decl(types.safeNavigation.esnext.1.ts, 4, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 4, 19))
+>z : Symbol(z, Decl(types.safeNavigation.esnext.1.ts, 4, 24))
+
+x5?.[y]?.[z];
+>x5 : Symbol(x5, Decl(types.safeNavigation.esnext.1.ts, 4, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 8, 13))
+>z : Symbol(z, Decl(types.safeNavigation.esnext.1.ts, 9, 13))
+
+x6?.y = 1;
+>x6?.y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 5, 19))
+>x6 : Symbol(x6, Decl(types.safeNavigation.esnext.1.ts, 5, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 5, 19))
+
+x6?.y += 1;
+>x6?.y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 5, 19))
+>x6 : Symbol(x6, Decl(types.safeNavigation.esnext.1.ts, 5, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 5, 19))
+
+x6?.y *= 1;
+>x6?.y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 5, 19))
+>x6 : Symbol(x6, Decl(types.safeNavigation.esnext.1.ts, 5, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 5, 19))
+
+x6?.y++;
+>x6?.y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 5, 19))
+>x6 : Symbol(x6, Decl(types.safeNavigation.esnext.1.ts, 5, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 5, 19))
+
+++x6?.y;
+>x6?.y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 5, 19))
+>x6 : Symbol(x6, Decl(types.safeNavigation.esnext.1.ts, 5, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.1.ts, 5, 19))
+

tests/baselines/reference/types.safeNavigation.esnext.1.types

@@ -0,0 +1,188 @@
+=== tests/cases/conformance/types/safeNavigation/types.safeNavigation.esnext.1.ts ===
+declare const x1: (() => number) | undefined | null;
+>x1 : () => number
+>null : null
+
+declare const x2: { y: (() => number) | undefined | null; };
+>x2 : { y: () => number; }
+>y : () => number
+>null : null
+
+declare const x3: { y: (() => number) | undefined | null; } | undefined | null;
+>x3 : { y: () => number; }
+>y : () => number
+>null : null
+>null : null
+
+declare const x4: { y: { z: (() => number) | undefined | null; } };
+>x4 : { y: { z: () => number; }; }
+>y : { z: () => number; }
+>z : () => number
+>null : null
+
+declare const x5: { y: { z: (() => number) | undefined | null; } | undefined | null } | undefined | null;
+>x5 : { y: { z: () => number; }; }
+>y : { z: () => number; }
+>z : () => number
+>null : null
+>null : null
+>null : null
+
+declare const x6: { y: number } | undefined | null;
+>x6 : { y: number; }
+>y : number
+>null : null
+
+declare const x7: { y: any };
+>x7 : { y: any; }
+>y : any
+
+declare const x8: { y: { z: number } | undefined | null } | undefined | null;
+>x8 : { y: { z: number; }; }
+>y : { z: number; }
+>z : number
+>null : null
+>null : null
+
+declare const y: "y";
+>y : "y"
+
+declare const z: "z";
+>z : "z"
+
+x1?.();
+>x1?.() : number
+>x1 : () => number
+
+(x1)?.();
+>(x1)?.() : number
+>(x1) : () => number
+>x1 : () => number
+
+x2.y?.();
+>x2.y?.() : number
+>x2.y : () => number
+>x2 : { y: () => number; }
+>y : () => number
+
+x2[y]?.();
+>x2[y]?.() : number
+>x2[y] : () => number
+>x2 : { y: () => number; }
+>y : "y"
+
+(x2.y)?.();
+>(x2.y)?.() : number
+>(x2.y) : () => number
+>x2.y : () => number
+>x2 : { y: () => number; }
+>y : () => number
+
+(x2[y])?.();
+>(x2[y])?.() : number
+>(x2[y]) : () => number
+>x2[y] : () => number
+>x2 : { y: () => number; }
+>y : "y"
+
+x3?.y?.();
+>x3?.y?.() : number
+>x3?.y : () => number
+>x3 : { y: () => number; }
+>y : () => number
+
+x3?.[y]?.();
+>x3?.[y]?.() : number
+>x3?.[y] : () => number
+>x3 : { y: () => number; }
+>y : "y"
+
+x4.y.z?.();
+>x4.y.z?.() : number
+>x4.y.z : () => number
+>x4.y : { z: () => number; }
+>x4 : { y: { z: () => number; }; }
+>y : { z: () => number; }
+>z : () => number
+
+x4.y[z]?.();
+>x4.y[z]?.() : number
+>x4.y[z] : () => number
+>x4.y : { z: () => number; }
+>x4 : { y: { z: () => number; }; }
+>y : { z: () => number; }
+>z : "z"
+
+(x4.y.z)?.();
+>(x4.y.z)?.() : number
+>(x4.y.z) : () => number
+>x4.y.z : () => number
+>x4.y : { z: () => number; }
+>x4 : { y: { z: () => number; }; }
+>y : { z: () => number; }
+>z : () => number
+
+(x4.y[z])?.();
+>(x4.y[z])?.() : number
+>(x4.y[z]) : () => number
+>x4.y[z] : () => number
+>x4.y : { z: () => number; }
+>x4 : { y: { z: () => number; }; }
+>y : { z: () => number; }
+>z : "z"
+
+x5?.y?.z?.();
+>x5?.y?.z?.() : number
+>x5?.y?.z : () => number
+>x5?.y : { z: () => number; }
+>x5 : { y: { z: () => number; }; }
+>y : { z: () => number; }
+>z : () => number
+
+x5?.y?.z;
+>x5?.y?.z : () => number
+>x5?.y : { z: () => number; }
+>x5 : { y: { z: () => number; }; }
+>y : { z: () => number; }
+>z : () => number
+
+x5?.[y]?.[z];
+>x5?.[y]?.[z] : () => number
+>x5?.[y] : { z: () => number; }
+>x5 : { y: { z: () => number; }; }
+>y : "y"
+>z : "z"
+
+x6?.y = 1;
+>x6?.y = 1 : 1
+>x6?.y : number
+>x6 : { y: number; }
+>y : number
+>1 : 1
+
+x6?.y += 1;
+>x6?.y += 1 : number
+>x6?.y : number
+>x6 : { y: number; }
+>y : number
+>1 : 1
+
+x6?.y *= 1;
+>x6?.y *= 1 : number
+>x6?.y : number
+>x6 : { y: number; }
+>y : number
+>1 : 1
+
+x6?.y++;
+>x6?.y++ : number
+>x6?.y : number
+>x6 : { y: number; }
+>y : number
+
+++x6?.y;
+>++x6?.y : number
+>x6?.y : number
+>x6 : { y: number; }
+>y : number
+

tests/baselines/reference/types.safeNavigation.esnext.2.symbols

@@ -0,0 +1,164 @@
+=== tests/cases/conformance/types/safeNavigation/types.safeNavigation.esnext.2.ts ===
+declare const x1: (() => number) | undefined | null;
+>x1 : Symbol(x1, Decl(types.safeNavigation.esnext.2.ts, 0, 13))
+
+declare const x2: { y: (() => number) | undefined | null; };
+>x2 : Symbol(x2, Decl(types.safeNavigation.esnext.2.ts, 1, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 1, 19))
+
+declare const x3: { y: (() => number) | undefined | null; } | undefined | null;
+>x3 : Symbol(x3, Decl(types.safeNavigation.esnext.2.ts, 2, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 2, 19))
+
+declare const x4: { y: { z: (() => number) | undefined | null; } };
+>x4 : Symbol(x4, Decl(types.safeNavigation.esnext.2.ts, 3, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 3, 19))
+>z : Symbol(z, Decl(types.safeNavigation.esnext.2.ts, 3, 24))
+
+declare const x5: { y: { z: (() => number) | undefined | null; } | undefined | null } | undefined | null;
+>x5 : Symbol(x5, Decl(types.safeNavigation.esnext.2.ts, 4, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 4, 19))
+>z : Symbol(z, Decl(types.safeNavigation.esnext.2.ts, 4, 24))
+
+declare const x6: { y: number } | undefined | null;
+>x6 : Symbol(x6, Decl(types.safeNavigation.esnext.2.ts, 5, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 5, 19))
+
+declare const x7: { y: any };
+>x7 : Symbol(x7, Decl(types.safeNavigation.esnext.2.ts, 6, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 6, 19))
+
+declare const x8: { y: { z: number } | undefined | null } | undefined | null;
+>x8 : Symbol(x8, Decl(types.safeNavigation.esnext.2.ts, 7, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 7, 19))
+>z : Symbol(z, Decl(types.safeNavigation.esnext.2.ts, 7, 24))
+
+declare const y: "y";
+>y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 8, 13))
+
+declare const z: "z";
+>z : Symbol(z, Decl(types.safeNavigation.esnext.2.ts, 9, 13))
+
+const a1 = x1?.();
+>a1 : Symbol(a1, Decl(types.safeNavigation.esnext.2.ts, 11, 5))
+>x1 : Symbol(x1, Decl(types.safeNavigation.esnext.2.ts, 0, 13))
+
+const a2 = (x1)?.();
+>a2 : Symbol(a2, Decl(types.safeNavigation.esnext.2.ts, 12, 5))
+>x1 : Symbol(x1, Decl(types.safeNavigation.esnext.2.ts, 0, 13))
+
+const a3 = x2.y?.();
+>a3 : Symbol(a3, Decl(types.safeNavigation.esnext.2.ts, 14, 5))
+>x2.y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 1, 19))
+>x2 : Symbol(x2, Decl(types.safeNavigation.esnext.2.ts, 1, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 1, 19))
+
+const a4 = x2[y]?.();
+>a4 : Symbol(a4, Decl(types.safeNavigation.esnext.2.ts, 15, 5))
+>x2 : Symbol(x2, Decl(types.safeNavigation.esnext.2.ts, 1, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 8, 13))
+
+const a5 = (x2.y)?.();
+>a5 : Symbol(a5, Decl(types.safeNavigation.esnext.2.ts, 16, 5))
+>x2.y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 1, 19))
+>x2 : Symbol(x2, Decl(types.safeNavigation.esnext.2.ts, 1, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 1, 19))
+
+const a6 = (x2[y])?.();
+>a6 : Symbol(a6, Decl(types.safeNavigation.esnext.2.ts, 17, 5))
+>x2 : Symbol(x2, Decl(types.safeNavigation.esnext.2.ts, 1, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 8, 13))
+
+const a7 = x3?.y?.();
+>a7 : Symbol(a7, Decl(types.safeNavigation.esnext.2.ts, 18, 5))
+>x3?.y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 2, 19))
+>x3 : Symbol(x3, Decl(types.safeNavigation.esnext.2.ts, 2, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 2, 19))
+
+const a8 = x3?.[y]?.();
+>a8 : Symbol(a8, Decl(types.safeNavigation.esnext.2.ts, 19, 5))
+>x3 : Symbol(x3, Decl(types.safeNavigation.esnext.2.ts, 2, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 8, 13))
+
+const a9 = x4.y.z?.();
+>a9 : Symbol(a9, Decl(types.safeNavigation.esnext.2.ts, 21, 5))
+>x4.y.z : Symbol(z, Decl(types.safeNavigation.esnext.2.ts, 3, 24))
+>x4.y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 3, 19))
+>x4 : Symbol(x4, Decl(types.safeNavigation.esnext.2.ts, 3, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 3, 19))
+>z : Symbol(z, Decl(types.safeNavigation.esnext.2.ts, 3, 24))
+
+const a10 = x4.y[z]?.();
+>a10 : Symbol(a10, Decl(types.safeNavigation.esnext.2.ts, 22, 5))
+>x4.y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 3, 19))
+>x4 : Symbol(x4, Decl(types.safeNavigation.esnext.2.ts, 3, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 3, 19))
+>z : Symbol(z, Decl(types.safeNavigation.esnext.2.ts, 9, 13))
+
+const a11 = (x4.y.z)?.();
+>a11 : Symbol(a11, Decl(types.safeNavigation.esnext.2.ts, 23, 5))
+>x4.y.z : Symbol(z, Decl(types.safeNavigation.esnext.2.ts, 3, 24))
+>x4.y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 3, 19))
+>x4 : Symbol(x4, Decl(types.safeNavigation.esnext.2.ts, 3, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 3, 19))
+>z : Symbol(z, Decl(types.safeNavigation.esnext.2.ts, 3, 24))
+
+const a12 = (x4.y[z])?.();
+>a12 : Symbol(a12, Decl(types.safeNavigation.esnext.2.ts, 24, 5))
+>x4.y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 3, 19))
+>x4 : Symbol(x4, Decl(types.safeNavigation.esnext.2.ts, 3, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 3, 19))
+>z : Symbol(z, Decl(types.safeNavigation.esnext.2.ts, 9, 13))
+
+const a13 = x5?.y?.z?.();
+>a13 : Symbol(a13, Decl(types.safeNavigation.esnext.2.ts, 25, 5))
+>x5?.y?.z : Symbol(z, Decl(types.safeNavigation.esnext.2.ts, 4, 24))
+>x5?.y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 4, 19))
+>x5 : Symbol(x5, Decl(types.safeNavigation.esnext.2.ts, 4, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 4, 19))
+>z : Symbol(z, Decl(types.safeNavigation.esnext.2.ts, 4, 24))
+
+const a14 = x5?.y?.z;
+>a14 : Symbol(a14, Decl(types.safeNavigation.esnext.2.ts, 26, 5))
+>x5?.y?.z : Symbol(z, Decl(types.safeNavigation.esnext.2.ts, 4, 24))
+>x5?.y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 4, 19))
+>x5 : Symbol(x5, Decl(types.safeNavigation.esnext.2.ts, 4, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 4, 19))
+>z : Symbol(z, Decl(types.safeNavigation.esnext.2.ts, 4, 24))
+
+const a15 = x5?.[y]?.[z];
+>a15 : Symbol(a15, Decl(types.safeNavigation.esnext.2.ts, 27, 5))
+>x5 : Symbol(x5, Decl(types.safeNavigation.esnext.2.ts, 4, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 8, 13))
+>z : Symbol(z, Decl(types.safeNavigation.esnext.2.ts, 9, 13))
+
+const a16 = x6?.y = 1;
+>a16 : Symbol(a16, Decl(types.safeNavigation.esnext.2.ts, 29, 5))
+>x6?.y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 5, 19))
+>x6 : Symbol(x6, Decl(types.safeNavigation.esnext.2.ts, 5, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 5, 19))
+
+const a17 = x6?.y += 1;
+>a17 : Symbol(a17, Decl(types.safeNavigation.esnext.2.ts, 30, 5))
+>x6?.y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 5, 19))
+>x6 : Symbol(x6, Decl(types.safeNavigation.esnext.2.ts, 5, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 5, 19))
+
+const a17a = x6?.y *= 1;
+>a17a : Symbol(a17a, Decl(types.safeNavigation.esnext.2.ts, 31, 5))
+>x6?.y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 5, 19))
+>x6 : Symbol(x6, Decl(types.safeNavigation.esnext.2.ts, 5, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 5, 19))
+
+const a18 = x6?.y++;
+>a18 : Symbol(a18, Decl(types.safeNavigation.esnext.2.ts, 32, 5))
+>x6?.y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 5, 19))
+>x6 : Symbol(x6, Decl(types.safeNavigation.esnext.2.ts, 5, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 5, 19))
+
+const a19 = ++x6?.y;
+>a19 : Symbol(a19, Decl(types.safeNavigation.esnext.2.ts, 33, 5))
+>x6?.y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 5, 19))
+>x6 : Symbol(x6, Decl(types.safeNavigation.esnext.2.ts, 5, 13))
+>y : Symbol(y, Decl(types.safeNavigation.esnext.2.ts, 5, 19))
+

tests/baselines/reference/types.safeNavigation.esnext.2.types

@@ -0,0 +1,208 @@
+=== tests/cases/conformance/types/safeNavigation/types.safeNavigation.esnext.2.ts ===
+declare const x1: (() => number) | undefined | null;
+>x1 : (() => number) | null | undefined
+>null : null
+
+declare const x2: { y: (() => number) | undefined | null; };
+>x2 : { y: (() => number) | null | undefined; }
+>y : (() => number) | null | undefined
+>null : null
+
+declare const x3: { y: (() => number) | undefined | null; } | undefined | null;
+>x3 : { y: (() => number) | null | undefined; } | null | undefined
+>y : (() => number) | null | undefined
+>null : null
+>null : null
+
+declare const x4: { y: { z: (() => number) | undefined | null; } };
+>x4 : { y: { z: (() => number) | null | undefined; }; }
+>y : { z: (() => number) | null | undefined; }
+>z : (() => number) | null | undefined
+>null : null
+
+declare const x5: { y: { z: (() => number) | undefined | null; } | undefined | null } | undefined | null;
+>x5 : { y: { z: (() => number) | null | undefined; } | null | undefined; } | null | undefined
+>y : { z: (() => number) | null | undefined; } | null | undefined
+>z : (() => number) | null | undefined
+>null : null
+>null : null
+>null : null
+
+declare const x6: { y: number } | undefined | null;
+>x6 : { y: number; } | null | undefined
+>y : number
+>null : null
+
+declare const x7: { y: any };
+>x7 : { y: any; }
+>y : any
+
+declare const x8: { y: { z: number } | undefined | null } | undefined | null;
+>x8 : { y: { z: number; } | null | undefined; } | null | undefined
+>y : { z: number; } | null | undefined
+>z : number
+>null : null
+>null : null
+
+declare const y: "y";
+>y : "y"
+
+declare const z: "z";
+>z : "z"
+
+const a1 = x1?.();
+>a1 : number | undefined
+>x1?.() : number
+>x1 : (() => number) | null | undefined
+
+const a2 = (x1)?.();
+>a2 : number | undefined
+>(x1)?.() : number
+>(x1) : (() => number) | null | undefined
+>x1 : (() => number) | null | undefined
+
+const a3 = x2.y?.();
+>a3 : number | undefined
+>x2.y?.() : number
+>x2.y : (() => number) | null | undefined
+>x2 : { y: (() => number) | null | undefined; }
+>y : (() => number) | null | undefined
+
+const a4 = x2[y]?.();
+>a4 : number | undefined
+>x2[y]?.() : number
+>x2[y] : (() => number) | null | undefined
+>x2 : { y: (() => number) | null | undefined; }
+>y : "y"
+
+const a5 = (x2.y)?.();
+>a5 : number | undefined
+>(x2.y)?.() : number
+>(x2.y) : (() => number) | null | undefined
+>x2.y : (() => number) | null | undefined
+>x2 : { y: (() => number) | null | undefined; }
+>y : (() => number) | null | undefined
+
+const a6 = (x2[y])?.();
+>a6 : number | undefined
+>(x2[y])?.() : number
+>(x2[y]) : (() => number) | null | undefined
+>x2[y] : (() => number) | null | undefined
+>x2 : { y: (() => number) | null | undefined; }
+>y : "y"
+
+const a7 = x3?.y?.();
+>a7 : number | undefined
+>x3?.y?.() : number
+>x3?.y : (() => number) | null | undefined
+>x3 : { y: (() => number) | null | undefined; } | null | undefined
+>y : (() => number) | null | undefined
+
+const a8 = x3?.[y]?.();
+>a8 : number | undefined
+>x3?.[y]?.() : number
+>x3?.[y] : (() => number) | null | undefined
+>x3 : { y: (() => number) | null | undefined; } | null | undefined
+>y : "y"
+
+const a9 = x4.y.z?.();
+>a9 : number | undefined
+>x4.y.z?.() : number
+>x4.y.z : (() => number) | null | undefined
+>x4.y : { z: (() => number) | null | undefined; }
+>x4 : { y: { z: (() => number) | null | undefined; }; }
+>y : { z: (() => number) | null | undefined; }
+>z : (() => number) | null | undefined
+
+const a10 = x4.y[z]?.();
+>a10 : number | undefined
+>x4.y[z]?.() : number
+>x4.y[z] : (() => number) | null | undefined
+>x4.y : { z: (() => number) | null | undefined; }
+>x4 : { y: { z: (() => number) | null | undefined; }; }
+>y : { z: (() => number) | null | undefined; }
+>z : "z"
+
+const a11 = (x4.y.z)?.();
+>a11 : number | undefined
+>(x4.y.z)?.() : number
+>(x4.y.z) : (() => number) | null | undefined
+>x4.y.z : (() => number) | null | undefined
+>x4.y : { z: (() => number) | null | undefined; }
+>x4 : { y: { z: (() => number) | null | undefined; }; }
+>y : { z: (() => number) | null | undefined; }
+>z : (() => number) | null | undefined
+
+const a12 = (x4.y[z])?.();
+>a12 : number | undefined
+>(x4.y[z])?.() : number
+>(x4.y[z]) : (() => number) | null | undefined
+>x4.y[z] : (() => number) | null | undefined
+>x4.y : { z: (() => number) | null | undefined; }
+>x4 : { y: { z: (() => number) | null | undefined; }; }
+>y : { z: (() => number) | null | undefined; }
+>z : "z"
+
+const a13 = x5?.y?.z?.();
+>a13 : number | undefined
+>x5?.y?.z?.() : number
+>x5?.y?.z : (() => number) | null | undefined
+>x5?.y : { z: (() => number) | null | undefined; } | null | undefined
+>x5 : { y: { z: (() => number) | null | undefined; } | null | undefined; } | null | undefined
+>y : { z: (() => number) | null | undefined; } | null | undefined
+>z : (() => number) | null | undefined
+
+const a14 = x5?.y?.z;
+>a14 : (() => number) | null | undefined
+>x5?.y?.z : (() => number) | null | undefined
+>x5?.y : { z: (() => number) | null | undefined; } | null | undefined
+>x5 : { y: { z: (() => number) | null | undefined; } | null | undefined; } | null | undefined
+>y : { z: (() => number) | null | undefined; } | null | undefined
+>z : (() => number) | null | undefined
+
+const a15 = x5?.[y]?.[z];
+>a15 : (() => number) | null | undefined
+>x5?.[y]?.[z] : (() => number) | null | undefined
+>x5?.[y] : { z: (() => number) | null | undefined; } | null | undefined
+>x5 : { y: { z: (() => number) | null | undefined; } | null | undefined; } | null | undefined
+>y : "y"
+>z : "z"
+
+const a16 = x6?.y = 1;
+>a16 : 1
+>x6?.y = 1 : 1
+>x6?.y : number | undefined
+>x6 : { y: number; } | null | undefined
+>y : number | undefined
+>1 : 1
+
+const a17 = x6?.y += 1;
+>a17 : number | undefined
+>x6?.y += 1 : number | undefined
+>x6?.y : number | undefined
+>x6 : { y: number; } | null | undefined
+>y : number | undefined
+>1 : 1
+
+const a17a = x6?.y *= 1;
+>a17a : number | undefined
+>x6?.y *= 1 : number | undefined
+>x6?.y : number | undefined
+>x6 : { y: number; } | null | undefined
+>y : number | undefined
+>1 : 1
+
+const a18 = x6?.y++;
+>a18 : number | undefined
+>x6?.y++ : number | undefined
+>x6?.y : number | undefined
+>x6 : { y: number; } | null | undefined
+>y : number | undefined
+
+const a19 = ++x6?.y;
+>a19 : number | undefined
+>++x6?.y : number | undefined
+>x6?.y : number | undefined
+>x6 : { y: number; } | null | undefined
+>y : number | undefined
+

tests/cases/conformance/emitter/es2015/safeNavigation/emitter.safeNavigation.es2015.ts

@@ -0,0 +1,323 @@
+// @target: es2015
+// @lib: esnext
+// @module: commonjs
+// @experimentalDecorators: true
+// @filename: declarations.d.ts
+declare var x: any;
+declare var y: any;
+declare var f: ({
+    (): void;
+    <T>(): void;
+    new (): any;
+    new <T>(): any;
+}) | undefined;
+declare var o: { y: typeof f; }
+declare class Base { x(): any; }
+declare namespace M {
+    export class y {}
+    export class z<T> {}
+}
+// @filename: propertyAccessOk.ts
+x.y
+x?.y
+x?.y.z
+x.y?.z
+x?.y?.z
+// @filename: elementAccessOk.ts
+x["y"]
+x?.["y"]
+x?.["y"]["z"]
+x["y"]?.["z"]
+x?.["y"]?.["z"]
+// @filename: callExpressionOk.ts
+x()
+x?.()
+x.y?.()
+x["y"]?.()
+f?.<number>()
+o.y?.<number>()
+o["y"]?.<number>()
+// @filename: newExpressionOk.ts
+new x()
+new x.y?.()
+new x["y"]?.()
+new f?.<number>()
+new o.y?.<number>()
+new o["y"]?.<number>()
+// @filename: mixedOk.ts
+x?.y?.["z"]
+x?.["y"]?.z
+x?.y()
+x?.y?.()
+o?.y<number>()
+o?.y?.<number>()
+x?.["z"]()
+x?.["z"]?.()
+o?.["y"]<number>()
+o?.["y"]?.<number>()
+// @filename: mutationOk.ts
+x?.y = 1
+x?.y += 1;
+x?.y -= 1;
+x?.y *= 1;
+x?.y /= 1;
+x?.y %= 1;
+x?.y **= 1;
+x?.y |= 1;
+x?.y &= 1;
+x?.y ^= 1;
+x?.y <<= 1;
+x?.y >>= 1;
+x?.y >>>= 1;
+x?.y++;
+x?.y--;
+++x?.y;
+--x?.y;
+delete x?.y;
+x?.["y"] = 1
+x?.["y"] += 1;
+x?.["y"] -= 1;
+x?.["y"] *= 1;
+x?.["y"] /= 1;
+x?.["y"] %= 1;
+x?.["y"] **= 1;
+x?.["y"] |= 1;
+x?.["y"] &= 1;
+x?.["y"] ^= 1;
+x?.["y"] <<= 1;
+x?.["y"] >>= 1;
+x?.["y"] >>>= 1;
+x?.["y"]++;
+x?.["y"]--;
+++x?.["y"];
+--x?.["y"];
+delete x?.["y"];
+// @filename: arrayAssignmentPatternOk.ts
+[x?.y] = [1];
+[x?.["y"]] = [1];
+[...x?.y] = [1];
+[...x?.["y"]] = [1];
+// @filename: objectAssignmentPatternOk.ts
+({ a: x?.y } = { a: 1 });
+({ a: x?.["y"] } = { a: 1 });
+// @filename: questionDotDigitIsConditionalOk.ts
+x?.3:1;
+// @filename: superPropertyInvocationOk.ts
+// supported for invocation of super property
+void class extends Base {
+    m() {
+        super.x?.();
+        super["x"]?.();
+    }
+}
+
+// @filename: generalParsingOk.ts
+// object literals
+// - computed property names
+void { [x?.y]: 1 }
+void { [x?.["y"]]: 1 }
+void { [x?.()]: 1 }
+void { [new x?.()]: 1 }
+// - property assignments
+void { a: x?.y }
+void { a: x?.["y"] }
+void { a: x?.() }
+void { a: new x?.() }
+
+// classes
+// - computed property names
+// void class { [x?.y] = 1 }        // legal parse, but causes a checker error
+// void class { [x?.["y"]] = 1 }    // legal parse, but causes a checker error
+// void class { [x?.()] = 1 }       // legal parse, but causes a checker error
+// void class { [new f?.()] = 1 }   // legal parse, but causes a checker error
+void class { [Symbol?.toStringTag] = "" }
+// - property declarations
+void class { a = x?.y }
+void class { a = x?.["y"] }
+void class { a = x?.() }
+void class { a = new x?.() }
+// - heritage clauses
+void class extends M?.y {}
+void class extends M?.["y"] {}
+void class extends M?.z<number> {}
+// - class decorators
+@x?.y class C1 {}
+@x?.["y"] class C2 {}
+@x?.() class C3 {}
+@new x?.() class C4 {}
+// - member decorators
+class C5 { @x?.y m() {} }
+class C6 { @x?.["y"] m() {} } // allowed as ?.[ is not ambiguous with computed property names
+class C7 { @x?.() m() {} }
+class C8 { @new x?.() m () {} }
+// - parameter decorators
+class C9 { m(@x?.y a) {} }
+class C10 { m(@x?.["y"] a) {} }
+class C11 { m(@x?.() a) {} }
+class C12 { m(@new x?.() a) {} }
+
+// functions
+// - parameters
+void function (a = x?.y) {}
+void function (a = x?.["y"]) {}
+void function (a = x?.()) {}
+void function (a = new x?.()) {}
+// - binding elements
+//   - initializers
+void function ({ a = x?.y }) {}
+void function ({ a = x?.["y"] }) {}
+void function ({ a = x?.() }) {}
+void function ({ a = new x?.() }) {}
+//   - computed properties
+void function ({ [x?.y]: a }) {}
+void function ({ [x?.["y"]]: a }) {}
+void function ({ [x?.()]: a }) {}
+void function ({ [new x?.()]: a }) {}
+
+// arrow functions
+// - parameters
+((a = x?.y) => {});
+((a = x?.["y"]) => {});
+((a = x?.()) => {});
+((a = new x?.()) => {});
+// - expression bodies
+(() => x?.y);
+(() => x?.["y"]);
+(() => x?.());
+(() => new x?.());
+
+// parenthesis
+(x?.y);
+
+// comma
+x?.y, f();
+f(), x?.y;
+
+// conditional
+x?.y ? 0 : 1
+0 ? x?.y : 1;
+0 ? 1 : x?.y;
+
+// binary
+x?.y + 1;
+x?.y - 1;
+x?.y * 1;
+x?.y / 1;
+x?.y ** 1;
+x?.y % 1;
+x?.y ^ 1;
+x?.y & 1;
+x?.y | 1;
+x?.y << 1;
+x?.y >> 1;
+x?.y >>> 1;
+x?.y && 1;
+x?.y || 1;
+x?.y == 1;
+x?.y === 1;
+x?.y != 1;
+x?.y !== 1;
+x?.y < 1;
+x?.y <= 1;
+x?.y > 1;
+x?.y >= 1;
+1 + x?.y;
+1 - x?.y;
+1 * x?.y;
+1 / x?.y;
+1 ** x?.y;
+1 % x?.y;
+1 ^ x?.y;
+1 & x?.y;
+1 | x?.y;
+1 << x?.y;
+1 >> x?.y;
+1 >>> x?.y;
+1 && x?.y;
+1 || x?.y;
+1 == x?.y;
+1 === x?.y;
+1 != x?.y;
+1 !== x?.y;
+1 < x?.y;
+1 <= x?.y;
+1 > x?.y;
+1 >= x?.y;
+
+// prefix unary
++x?.y;
+-x?.y;
+!x?.y;
+~x?.y;
+
+// unary
+void x?.y;
+typeof x?.y;
+void function * () { yield x?.y; }
+void async function() { await x?.y; }
+
+// notnull
+x?.y!.z;
+
+// assertions
+<string>x?.y;
+x?.y as string;
+
+// array literals
+[x?.y];
+[, x?.y];
+[...x?.y];
+
+// literals
+1?.toString(); // no need for `..`
+1.?.toString();
+.0?.toString();
+4e3?.toString();
+1.e3?.toString();
+""?.toString();
+''?.toString();
+``?.toString();
+/./?.toString();
+/./g?.toString();
+true?.toString();
+false?.toString();
+
+// templates
+`${x?.y}`;
+
+// variables
+var v = x?.y;
+var [v] = x?.y;
+var [v = x?.y] = [1];
+var {v} = x?.y;
+var {v = x?.y} = {v:1};
+var {[x?.y]: v} = null;
+
+// if/else if
+if (x?.y) {}
+if (1) {} else if (x?.y) {}
+
+// switch
+switch (x?.y) {}
+switch (1) { case x?.y: break; }
+
+// do/while
+do {} while (x?.y)
+while (x?.y) {}
+
+// for
+for (x?.y; x?.y; x?.y);
+
+// for..in
+for (x?.y in {});
+
+// for..of
+for (x?.y of []);
+
+// enums
+enum E {
+    a = x?.y
+}
+
+// @filename: exportsOk.ts
+export default x?.y;

tests/cases/conformance/emitter/es3/safeNavigation/emitter.safeNavigation.es3.ts

@@ -0,0 +1,322 @@
+// @target: es3
+// @lib: esnext
+// @module: commonjs
+// @experimentalDecorators: true
+// @filename: declarations.d.ts
+declare var x: any;
+declare var y: any;
+declare var f: ({
+    (): void;
+    <T>(): void;
+    new (): any;
+    new <T>(): any;
+}) | undefined;
+declare var o: { y: typeof f; }
+declare class Base { x(): any; }
+declare namespace M {
+    export class y {}
+    export class z<T> {}
+}
+// @filename: propertyAccessOk.ts
+x.y
+x?.y
+x?.y.z
+x.y?.z
+x?.y?.z
+// @filename: elementAccessOk.ts
+x["y"]
+x?.["y"]
+x?.["y"]["z"]
+x["y"]?.["z"]
+x?.["y"]?.["z"]
+// @filename: callExpressionOk.ts
+x()
+x?.()
+x.y?.()
+x["y"]?.()
+f?.<number>()
+o.y?.<number>()
+o["y"]?.<number>()
+// @filename: newExpressionOk.ts
+new x()
+new x.y?.()
+new x["y"]?.()
+new f?.<number>()
+new o.y?.<number>()
+new o["y"]?.<number>()
+// @filename: mixedOk.ts
+x?.y?.["z"]
+x?.["y"]?.z
+x?.y()
+x?.y?.()
+o?.y<number>()
+o?.y?.<number>()
+x?.["z"]()
+x?.["z"]?.()
+o?.["y"]<number>()
+o?.["y"]?.<number>()
+// @filename: mutationOk.ts
+x?.y = 1
+x?.y += 1;
+x?.y -= 1;
+x?.y *= 1;
+x?.y /= 1;
+x?.y %= 1;
+x?.y **= 1;
+x?.y |= 1;
+x?.y &= 1;
+x?.y ^= 1;
+x?.y <<= 1;
+x?.y >>= 1;
+x?.y >>>= 1;
+x?.y++;
+x?.y--;
+++x?.y;
+--x?.y;
+delete x?.y;
+x?.["y"] = 1
+x?.["y"] += 1;
+x?.["y"] -= 1;
+x?.["y"] *= 1;
+x?.["y"] /= 1;
+x?.["y"] %= 1;
+x?.["y"] **= 1;
+x?.["y"] |= 1;
+x?.["y"] &= 1;
+x?.["y"] ^= 1;
+x?.["y"] <<= 1;
+x?.["y"] >>= 1;
+x?.["y"] >>>= 1;
+x?.["y"]++;
+x?.["y"]--;
+++x?.["y"];
+--x?.["y"];
+delete x?.["y"];
+// @filename: arrayAssignmentPatternOk.ts
+[x?.y] = [1];
+[x?.["y"]] = [1];
+[...x?.y] = [1];
+[...x?.["y"]] = [1];
+// @filename: objectAssignmentPatternOk.ts
+({ a: x?.y } = { a: 1 });
+({ a: x?.["y"] } = { a: 1 });
+// @filename: questionDotDigitIsConditionalOk.ts
+x?.3:1;
+// @filename: superPropertyInvocationOk.ts
+// supported for invocation of super property
+void class extends Base {
+    m() {
+        super.x?.();
+    }
+}
+
+// @filename: generalParsingOk.ts
+// object literals
+// - computed property names
+void { [x?.y]: 1 }
+void { [x?.["y"]]: 1 }
+void { [x?.()]: 1 }
+void { [new x?.()]: 1 }
+// - property assignments
+void { a: x?.y }
+void { a: x?.["y"] }
+void { a: x?.() }
+void { a: new x?.() }
+
+// classes
+// - computed property names
+// void class { [x?.y] = 1 }        // legal parse, but causes a checker error
+// void class { [x?.["y"]] = 1 }    // legal parse, but causes a checker error
+// void class { [x?.()] = 1 }       // legal parse, but causes a checker error
+// void class { [new f?.()] = 1 }   // legal parse, but causes a checker error
+void class { [Symbol?.toStringTag] = "" }
+// - property declarations
+void class { a = x?.y }
+void class { a = x?.["y"] }
+void class { a = x?.() }
+void class { a = new x?.() }
+// - heritage clauses
+void class extends M?.y {}
+void class extends M?.["y"] {}
+void class extends M?.z<number> {}
+// - class decorators
+@x?.y class C1 {}
+@x?.["y"] class C2 {}
+@x?.() class C3 {}
+@new x?.() class C4 {}
+// - member decorators
+class C5 { @x?.y m() {} }
+class C6 { @x?.["y"] m() {} } // allowed as ?.[ is not ambiguous with computed property names
+class C7 { @x?.() m() {} }
+class C8 { @new x?.() m () {} }
+// - parameter decorators
+class C9 { m(@x?.y a) {} }
+class C10 { m(@x?.["y"] a) {} }
+class C11 { m(@x?.() a) {} }
+class C12 { m(@new x?.() a) {} }
+
+// functions
+// - parameters
+void function (a = x?.y) {}
+void function (a = x?.["y"]) {}
+void function (a = x?.()) {}
+void function (a = new x?.()) {}
+// - binding elements
+//   - initializers
+void function ({ a = x?.y }) {}
+void function ({ a = x?.["y"] }) {}
+void function ({ a = x?.() }) {}
+void function ({ a = new x?.() }) {}
+//   - computed properties
+void function ({ [x?.y]: a }) {}
+void function ({ [x?.["y"]]: a }) {}
+void function ({ [x?.()]: a }) {}
+void function ({ [new x?.()]: a }) {}
+
+// arrow functions
+// - parameters
+((a = x?.y) => {});
+((a = x?.["y"]) => {});
+((a = x?.()) => {});
+((a = new x?.()) => {});
+// - expression bodies
+(() => x?.y);
+(() => x?.["y"]);
+(() => x?.());
+(() => new x?.());
+
+// parenthesis
+(x?.y);
+
+// comma
+x?.y, f();
+f(), x?.y;
+
+// conditional
+x?.y ? 0 : 1
+0 ? x?.y : 1;
+0 ? 1 : x?.y;
+
+// binary
+x?.y + 1;
+x?.y - 1;
+x?.y * 1;
+x?.y / 1;
+x?.y ** 1;
+x?.y % 1;
+x?.y ^ 1;
+x?.y & 1;
+x?.y | 1;
+x?.y << 1;
+x?.y >> 1;
+x?.y >>> 1;
+x?.y && 1;
+x?.y || 1;
+x?.y == 1;
+x?.y === 1;
+x?.y != 1;
+x?.y !== 1;
+x?.y < 1;
+x?.y <= 1;
+x?.y > 1;
+x?.y >= 1;
+1 + x?.y;
+1 - x?.y;
+1 * x?.y;
+1 / x?.y;
+1 ** x?.y;
+1 % x?.y;
+1 ^ x?.y;
+1 & x?.y;
+1 | x?.y;
+1 << x?.y;
+1 >> x?.y;
+1 >>> x?.y;
+1 && x?.y;
+1 || x?.y;
+1 == x?.y;
+1 === x?.y;
+1 != x?.y;
+1 !== x?.y;
+1 < x?.y;
+1 <= x?.y;
+1 > x?.y;
+1 >= x?.y;
+
+// prefix unary
++x?.y;
+-x?.y;
+!x?.y;
+~x?.y;
+
+// unary
+void x?.y;
+typeof x?.y;
+void function * () { yield x?.y; }
+void async function() { await x?.y; }
+
+// notnull
+x?.y!.z;
+
+// assertions
+<string>x?.y;
+x?.y as string;
+
+// array literals
+[x?.y];
+[, x?.y];
+[...x?.y];
+
+// literals
+1?.toString(); // no need for `..`
+1.?.toString();
+.0?.toString();
+4e3?.toString();
+1.e3?.toString();
+""?.toString();
+''?.toString();
+``?.toString();
+/./?.toString();
+/./g?.toString();
+true?.toString();
+false?.toString();
+
+// templates
+`${x?.y}`;
+
+// variables
+var v = x?.y;
+var [v] = x?.y;
+var [v = x?.y] = [1];
+var {v} = x?.y;
+var {v = x?.y} = {v:1};
+var {[x?.y]: v} = null;
+
+// if/else if
+if (x?.y) {}
+if (1) {} else if (x?.y) {}
+
+// switch
+switch (x?.y) {}
+switch (1) { case x?.y: break; }
+
+// do/while
+do {} while (x?.y)
+while (x?.y) {}
+
+// for
+for (x?.y; x?.y; x?.y);
+
+// for..in
+for (x?.y in {});
+
+// for..of
+for (x?.y of []);
+
+// enums
+enum E {
+    a = x?.y
+}
+
+// @filename: exportsOk.ts
+export default x?.y;

tests/cases/conformance/emitter/es5/safeNavigation/emitter.safeNavigation.es5.ts

@@ -0,0 +1,322 @@
+// @target: es5
+// @lib: esnext
+// @module: commonjs
+// @experimentalDecorators: true
+// @filename: declarations.d.ts
+declare var x: any;
+declare var y: any;
+declare var f: ({
+    (): void;
+    <T>(): void;
+    new (): any;
+    new <T>(): any;
+}) | undefined;
+declare var o: { y: typeof f; }
+declare class Base { x(): any; }
+declare namespace M {
+    export class y {}
+    export class z<T> {}
+}
+// @filename: propertyAccessOk.ts
+x.y
+x?.y
+x?.y.z
+x.y?.z
+x?.y?.z
+// @filename: elementAccessOk.ts
+x["y"]
+x?.["y"]
+x?.["y"]["z"]
+x["y"]?.["z"]
+x?.["y"]?.["z"]
+// @filename: callExpressionOk.ts
+x()
+x?.()
+x.y?.()
+x["y"]?.()
+f?.<number>()
+o.y?.<number>()
+o["y"]?.<number>()
+// @filename: newExpressionOk.ts
+new x()
+new x.y?.()
+new x["y"]?.()
+new f?.<number>()
+new o.y?.<number>()
+new o["y"]?.<number>()
+// @filename: mixedOk.ts
+x?.y?.["z"]
+x?.["y"]?.z
+x?.y()
+x?.y?.()
+o?.y<number>()
+o?.y?.<number>()
+x?.["z"]()
+x?.["z"]?.()
+o?.["y"]<number>()
+o?.["y"]?.<number>()
+// @filename: mutationOk.ts
+x?.y = 1
+x?.y += 1;
+x?.y -= 1;
+x?.y *= 1;
+x?.y /= 1;
+x?.y %= 1;
+x?.y **= 1;
+x?.y |= 1;
+x?.y &= 1;
+x?.y ^= 1;
+x?.y <<= 1;
+x?.y >>= 1;
+x?.y >>>= 1;
+x?.y++;
+x?.y--;
+++x?.y;
+--x?.y;
+delete x?.y;
+x?.["y"] = 1
+x?.["y"] += 1;
+x?.["y"] -= 1;
+x?.["y"] *= 1;
+x?.["y"] /= 1;
+x?.["y"] %= 1;
+x?.["y"] **= 1;
+x?.["y"] |= 1;
+x?.["y"] &= 1;
+x?.["y"] ^= 1;
+x?.["y"] <<= 1;
+x?.["y"] >>= 1;
+x?.["y"] >>>= 1;
+x?.["y"]++;
+x?.["y"]--;
+++x?.["y"];
+--x?.["y"];
+delete x?.["y"];
+// @filename: arrayAssignmentPatternOk.ts
+[x?.y] = [1];
+[x?.["y"]] = [1];
+[...x?.y] = [1];
+[...x?.["y"]] = [1];
+// @filename: objectAssignmentPatternOk.ts
+({ a: x?.y } = { a: 1 });
+({ a: x?.["y"] } = { a: 1 });
+// @filename: questionDotDigitIsConditionalOk.ts
+x?.3:1;
+// @filename: superPropertyInvocationOk.ts
+// supported for invocation of super property
+void class extends Base {
+    m() {
+        super.x?.();
+    }
+}
+
+// @filename: generalParsingOk.ts
+// object literals
+// - computed property names
+void { [x?.y]: 1 }
+void { [x?.["y"]]: 1 }
+void { [x?.()]: 1 }
+void { [new x?.()]: 1 }
+// - property assignments
+void { a: x?.y }
+void { a: x?.["y"] }
+void { a: x?.() }
+void { a: new x?.() }
+
+// classes
+// - computed property names
+// void class { [x?.y] = 1 }        // legal parse, but causes a checker error
+// void class { [x?.["y"]] = 1 }    // legal parse, but causes a checker error
+// void class { [x?.()] = 1 }       // legal parse, but causes a checker error
+// void class { [new f?.()] = 1 }   // legal parse, but causes a checker error
+void class { [Symbol?.toStringTag] = "" }
+// - property declarations
+void class { a = x?.y }
+void class { a = x?.["y"] }
+void class { a = x?.() }
+void class { a = new x?.() }
+// - heritage clauses
+void class extends M?.y {}
+void class extends M?.["y"] {}
+void class extends M?.z<number> {}
+// - class decorators
+@x?.y class C1 {}
+@x?.["y"] class C2 {}
+@x?.() class C3 {}
+@new x?.() class C4 {}
+// - member decorators
+class C5 { @x?.y m() {} }
+class C6 { @x?.["y"] m() {} } // allowed as ?.[ is not ambiguous with computed property names
+class C7 { @x?.() m() {} }
+class C8 { @new x?.() m () {} }
+// - parameter decorators
+class C9 { m(@x?.y a) {} }
+class C10 { m(@x?.["y"] a) {} }
+class C11 { m(@x?.() a) {} }
+class C12 { m(@new x?.() a) {} }
+
+// functions
+// - parameters
+void function (a = x?.y) {}
+void function (a = x?.["y"]) {}
+void function (a = x?.()) {}
+void function (a = new x?.()) {}
+// - binding elements
+//   - initializers
+void function ({ a = x?.y }) {}
+void function ({ a = x?.["y"] }) {}
+void function ({ a = x?.() }) {}
+void function ({ a = new x?.() }) {}
+//   - computed properties
+void function ({ [x?.y]: a }) {}
+void function ({ [x?.["y"]]: a }) {}
+void function ({ [x?.()]: a }) {}
+void function ({ [new x?.()]: a }) {}
+
+// arrow functions
+// - parameters
+((a = x?.y) => {});
+((a = x?.["y"]) => {});
+((a = x?.()) => {});
+((a = new x?.()) => {});
+// - expression bodies
+(() => x?.y);
+(() => x?.["y"]);
+(() => x?.());
+(() => new x?.());
+
+// parenthesis
+(x?.y);
+
+// comma
+x?.y, f();
+f(), x?.y;
+
+// conditional
+x?.y ? 0 : 1
+0 ? x?.y : 1;
+0 ? 1 : x?.y;
+
+// binary
+x?.y + 1;
+x?.y - 1;
+x?.y * 1;
+x?.y / 1;
+x?.y ** 1;
+x?.y % 1;
+x?.y ^ 1;
+x?.y & 1;
+x?.y | 1;
+x?.y << 1;
+x?.y >> 1;
+x?.y >>> 1;
+x?.y && 1;
+x?.y || 1;
+x?.y == 1;
+x?.y === 1;
+x?.y != 1;
+x?.y !== 1;
+x?.y < 1;
+x?.y <= 1;
+x?.y > 1;
+x?.y >= 1;
+1 + x?.y;
+1 - x?.y;
+1 * x?.y;
+1 / x?.y;
+1 ** x?.y;
+1 % x?.y;
+1 ^ x?.y;
+1 & x?.y;
+1 | x?.y;
+1 << x?.y;
+1 >> x?.y;
+1 >>> x?.y;
+1 && x?.y;
+1 || x?.y;
+1 == x?.y;
+1 === x?.y;
+1 != x?.y;
+1 !== x?.y;
+1 < x?.y;
+1 <= x?.y;
+1 > x?.y;
+1 >= x?.y;
+
+// prefix unary
++x?.y;
+-x?.y;
+!x?.y;
+~x?.y;
+
+// unary
+void x?.y;
+typeof x?.y;
+void function * () { yield x?.y; }
+void async function() { await x?.y; }
+
+// notnull
+x?.y!.z;
+
+// assertions
+<string>x?.y;
+x?.y as string;
+
+// array literals
+[x?.y];
+[, x?.y];
+[...x?.y];
+
+// literals
+1?.toString(); // no need for `..`
+1.?.toString();
+.0?.toString();
+4e3?.toString();
+1.e3?.toString();
+""?.toString();
+''?.toString();
+``?.toString();
+/./?.toString();
+/./g?.toString();
+true?.toString();
+false?.toString();
+
+// templates
+`${x?.y}`;
+
+// variables
+var v = x?.y;
+var [v] = x?.y;
+var [v = x?.y] = [1];
+var {v} = x?.y;
+var {v = x?.y} = {v:1};
+var {[x?.y]: v} = null;
+
+// if/else if
+if (x?.y) {}
+if (1) {} else if (x?.y) {}
+
+// switch
+switch (x?.y) {}
+switch (1) { case x?.y: break; }
+
+// do/while
+do {} while (x?.y)
+while (x?.y) {}
+
+// for
+for (x?.y; x?.y; x?.y);
+
+// for..in
+for (x?.y in {});
+
+// for..of
+for (x?.y of []);
+
+// enums
+enum E {
+    a = x?.y
+}
+
+// @filename: exportsOk.ts
+export default x?.y;

tests/cases/conformance/emitter/esnext/safeNavigation/emitter.safeNavigation.esnext.ts

@@ -0,0 +1,323 @@
+// @target: esnext
+// @lib: esnext
+// @module: commonjs
+// @experimentalDecorators: true
+// @filename: declarations.d.ts
+declare var x: any;
+declare var y: any;
+declare var f: ({
+    (): void;
+    <T>(): void;
+    new (): any;
+    new <T>(): any;
+}) | undefined;
+declare var o: { y: typeof f; }
+declare class Base { x(): any; }
+declare namespace M {
+    export class y {}
+    export class z<T> {}
+}
+// @filename: propertyAccessOk.ts
+x.y
+x?.y
+x?.y.z
+x.y?.z
+x?.y?.z
+// @filename: elementAccessOk.ts
+x["y"]
+x?.["y"]
+x?.["y"]["z"]
+x["y"]?.["z"]
+x?.["y"]?.["z"]
+// @filename: callExpressionOk.ts
+x()
+x?.()
+x.y?.()
+x["y"]?.()
+f?.<number>()
+o.y?.<number>()
+o["y"]?.<number>()
+// @filename: newExpressionOk.ts
+new x()
+new x.y?.()
+new x["y"]?.()
+new f?.<number>()
+new o.y?.<number>()
+new o["y"]?.<number>()
+// @filename: mixedOk.ts
+x?.y?.["z"]
+x?.["y"]?.z
+x?.y()
+x?.y?.()
+o?.y<number>()
+o?.y?.<number>()
+x?.["z"]()
+x?.["z"]?.()
+o?.["y"]<number>()
+o?.["y"]?.<number>()
+// @filename: mutationOk.ts
+x?.y = 1
+x?.y += 1;
+x?.y -= 1;
+x?.y *= 1;
+x?.y /= 1;
+x?.y %= 1;
+x?.y **= 1;
+x?.y |= 1;
+x?.y &= 1;
+x?.y ^= 1;
+x?.y <<= 1;
+x?.y >>= 1;
+x?.y >>>= 1;
+x?.y++;
+x?.y--;
+++x?.y;
+--x?.y;
+delete x?.y;
+x?.["y"] = 1
+x?.["y"] += 1;
+x?.["y"] -= 1;
+x?.["y"] *= 1;
+x?.["y"] /= 1;
+x?.["y"] %= 1;
+x?.["y"] **= 1;
+x?.["y"] |= 1;
+x?.["y"] &= 1;
+x?.["y"] ^= 1;
+x?.["y"] <<= 1;
+x?.["y"] >>= 1;
+x?.["y"] >>>= 1;
+x?.["y"]++;
+x?.["y"]--;
+++x?.["y"];
+--x?.["y"];
+delete x?.["y"];
+// @filename: arrayAssignmentPatternOk.ts
+[x?.y] = [1];
+[x?.["y"]] = [1];
+[...x?.y] = [1];
+[...x?.["y"]] = [1];
+// @filename: objectAssignmentPatternOk.ts
+({ a: x?.y } = { a: 1 });
+({ a: x?.["y"] } = { a: 1 });
+// @filename: questionDotDigitIsConditionalOk.ts
+x?.3:1;
+// @filename: superPropertyInvocationOk.ts
+// supported for invocation of super property
+void class extends Base {
+    m() {
+        super.x?.();
+        super["x"]?.();
+    }
+}
+
+// @filename: generalParsingOk.ts
+// object literals
+// - computed property names
+void { [x?.y]: 1 }
+void { [x?.["y"]]: 1 }
+void { [x?.()]: 1 }
+void { [new x?.()]: 1 }
+// - property assignments
+void { a: x?.y }
+void { a: x?.["y"] }
+void { a: x?.() }
+void { a: new x?.() }
+
+// classes
+// - computed property names
+// void class { [x?.y] = 1 }        // legal parse, but causes a checker error
+// void class { [x?.["y"]] = 1 }    // legal parse, but causes a checker error
+// void class { [x?.()] = 1 }       // legal parse, but causes a checker error
+// void class { [new f?.()] = 1 }   // legal parse, but causes a checker error
+void class { [Symbol?.toStringTag] = "" }
+// - property declarations
+void class { a = x?.y }
+void class { a = x?.["y"] }
+void class { a = x?.() }
+void class { a = new x?.() }
+// - heritage clauses
+void class extends M?.y {}
+void class extends M?.["y"] {}
+void class extends M?.z<number> {}
+// - class decorators
+@x?.y class C1 {}
+@x?.["y"] class C2 {}
+@x?.() class C3 {}
+@new x?.() class C4 {}
+// - member decorators
+class C5 { @x?.y m() {} }
+class C6 { @x?.["y"] m() {} } // allowed as ?.[ is not ambiguous with computed property names
+class C7 { @x?.() m() {} }
+class C8 { @new x?.() m () {} }
+// - parameter decorators
+class C9 { m(@x?.y a) {} }
+class C10 { m(@x?.["y"] a) {} }
+class C11 { m(@x?.() a) {} }
+class C12 { m(@new x?.() a) {} }
+
+// functions
+// - parameters
+void function (a = x?.y) {}
+void function (a = x?.["y"]) {}
+void function (a = x?.()) {}
+void function (a = new x?.()) {}
+// - binding elements
+//   - initializers
+void function ({ a = x?.y }) {}
+void function ({ a = x?.["y"] }) {}
+void function ({ a = x?.() }) {}
+void function ({ a = new x?.() }) {}
+//   - computed properties
+void function ({ [x?.y]: a }) {}
+void function ({ [x?.["y"]]: a }) {}
+void function ({ [x?.()]: a }) {}
+void function ({ [new x?.()]: a }) {}
+
+// arrow functions
+// - parameters
+((a = x?.y) => {});
+((a = x?.["y"]) => {});
+((a = x?.()) => {});
+((a = new x?.()) => {});
+// - expression bodies
+(() => x?.y);
+(() => x?.["y"]);
+(() => x?.());
+(() => new x?.());
+
+// parenthesis
+(x?.y);
+
+// comma
+x?.y, f();
+f(), x?.y;
+
+// conditional
+x?.y ? 0 : 1
+0 ? x?.y : 1;
+0 ? 1 : x?.y;
+
+// binary
+x?.y + 1;
+x?.y - 1;
+x?.y * 1;
+x?.y / 1;
+x?.y ** 1;
+x?.y % 1;
+x?.y ^ 1;
+x?.y & 1;
+x?.y | 1;
+x?.y << 1;
+x?.y >> 1;
+x?.y >>> 1;
+x?.y && 1;
+x?.y || 1;
+x?.y == 1;
+x?.y === 1;
+x?.y != 1;
+x?.y !== 1;
+x?.y < 1;
+x?.y <= 1;
+x?.y > 1;
+x?.y >= 1;
+1 + x?.y;
+1 - x?.y;
+1 * x?.y;
+1 / x?.y;
+1 ** x?.y;
+1 % x?.y;
+1 ^ x?.y;
+1 & x?.y;
+1 | x?.y;
+1 << x?.y;
+1 >> x?.y;
+1 >>> x?.y;
+1 && x?.y;
+1 || x?.y;
+1 == x?.y;
+1 === x?.y;
+1 != x?.y;
+1 !== x?.y;
+1 < x?.y;
+1 <= x?.y;
+1 > x?.y;
+1 >= x?.y;
+
+// prefix unary
++x?.y;
+-x?.y;
+!x?.y;
+~x?.y;
+
+// unary
+void x?.y;
+typeof x?.y;
+void function * () { yield x?.y; }
+void async function() { await x?.y; }
+
+// notnull
+x?.y!.z;
+
+// assertions
+<string>x?.y;
+x?.y as string;
+
+// array literals
+[x?.y];
+[, x?.y];
+[...x?.y];
+
+// literals
+1?.toString(); // no need for `..`
+1.?.toString();
+.0?.toString();
+4e3?.toString();
+1.e3?.toString();
+""?.toString();
+''?.toString();
+``?.toString();
+/./?.toString();
+/./g?.toString();
+true?.toString();
+false?.toString();
+
+// templates
+`${x?.y}`;
+
+// variables
+var v = x?.y;
+var [v] = x?.y;
+var [v = x?.y] = [1];
+var {v} = x?.y;
+var {v = x?.y} = {v:1};
+var {[x?.y]: v} = null;
+
+// if/else if
+if (x?.y) {}
+if (1) {} else if (x?.y) {}
+
+// switch
+switch (x?.y) {}
+switch (1) { case x?.y: break; }
+
+// do/while
+do {} while (x?.y)
+while (x?.y) {}
+
+// for
+for (x?.y; x?.y; x?.y);
+
+// for..in
+for (x?.y in {});
+
+// for..of
+for (x?.y of []);
+
+// enums
+enum E {
+    a = x?.y
+}
+
+// @filename: exportsOk.ts
+export default x?.y;

tests/cases/conformance/parser/ecmascriptnext/safeNavigation/parser.safeNavigation.esnext.ts

@@ -0,0 +1,359 @@
+// @target: esnext
+// @lib: esnext
+// @noEmit: true
+// @module: commonjs
+// @experimentalDecorators: true
+// @filename: declarations.d.ts
+declare var x: any;
+declare var y: any;
+declare var f: ({
+    (): void;
+    <T>(): void;
+    new (): any;
+    new <T>(): any;
+}) | undefined;
+declare var o: { y: typeof f; }
+declare class Base { x: any; }
+declare namespace M {
+    export class y {}
+    export class z<T> {}
+}
+// @filename: propertyAccessOk.ts
+x.y
+x?.y
+x?.y.z
+x.y?.z
+x?.y?.z
+// @filename: elementAccessOk.ts
+x["y"]
+x?.["y"]
+x?.["y"]["z"]
+x["y"]?.["z"]
+x?.["y"]?.["z"]
+// @filename: callExpressionOk.ts
+x()
+x?.()
+x.y?.()
+x["y"]?.()
+f?.<number>()
+o.y?.<number>()
+o["y"]?.<number>()
+// @filename: newExpressionOk.ts
+new x()
+new x.y?.()
+new x["y"]?.()
+new f?.<number>()
+new o.y?.<number>()
+new o["y"]?.<number>()
+// @filename: mixedOk.ts
+x?.y?.["z"]
+x?.["y"]?.z
+x?.y()
+x?.y?.()
+o?.y<number>()
+o?.y?.<number>()
+x?.["z"]()
+x?.["z"]?.()
+o?.["y"]<number>()
+o?.["y"]?.<number>()
+// @filename: mutationOk.ts
+x?.y = 1
+x?.y += 1;
+x?.y -= 1;
+x?.y *= 1;
+x?.y /= 1;
+x?.y %= 1;
+x?.y **= 1;
+x?.y |= 1;
+x?.y &= 1;
+x?.y ^= 1;
+x?.y <<= 1;
+x?.y >>= 1;
+x?.y >>>= 1;
+x?.y++;
+x?.y--;
+++x?.y;
+--x?.y;
+delete x?.y;
+x?.["y"] = 1
+x?.["y"] += 1;
+x?.["y"] -= 1;
+x?.["y"] *= 1;
+x?.["y"] /= 1;
+x?.["y"] %= 1;
+x?.["y"] **= 1;
+x?.["y"] |= 1;
+x?.["y"] &= 1;
+x?.["y"] ^= 1;
+x?.["y"] <<= 1;
+x?.["y"] >>= 1;
+x?.["y"] >>>= 1;
+x?.["y"]++;
+x?.["y"]--;
+++x?.["y"];
+--x?.["y"];
+delete x?.["y"];
+// @filename: arrayAssignmentPatternOk.ts
+[x?.y] = [1];
+[x?.["y"]] = [1];
+[...x?.y] = [1];
+[...x?.["y"]] = [1];
+// @filename: objectAssignmentPatternOk.ts
+({ a: x?.y } = { a: 1 });
+({ a: x?.["y"] } = { a: 1 });
+// @filename: questionDotDigitIsConditionalOk.ts
+x?.3:1;
+// @filename: spaceInTokenError.ts
+x? .y
+// @filename: missingIdentifierError.ts
+x?.
+// @filename: taggedTemplateError.ts
+// not supported for tagged templates
+x?.`foo${bar}`
+// @filename: superError.ts
+// not supported for super
+void class extends Base {
+    constructor() {
+        super?.();
+    }
+}
+// @filename: superProperty1Error.ts
+// not supported for super property
+void class extends Base {
+    m() {
+        super?.x;
+    }
+}
+// @filename: superProperty2Error.ts
+// not supported for super property
+void class extends Base {
+    m() {
+        super?.["x"];
+    }
+}
+// @filename: superPropertyInvocationOk.ts
+// supported for invocation of super property
+void class extends Base {
+    m() {
+        super.x?.();
+        super["x"]?.();
+    }
+}
+// @filename: metaPropertyError.ts
+// not supported for meta property
+void class {
+    constructor() {
+        new?.target;
+    }
+}
+
+// @filename: generalParsingOk.ts
+// object literals
+// - computed property names
+void { [x?.y]: 1 }
+void { [x?.["y"]]: 1 }
+void { [x?.()]: 1 }
+void { [new x?.()]: 1 }
+// - property assignments
+void { a: x?.y }
+void { a: x?.["y"] }
+void { a: x?.() }
+void { a: new x?.() }
+
+// classes
+// - computed property names
+// void class { [x?.y] = 1 }        // legal parse, but causes a checker error
+// void class { [x?.["y"]] = 1 }    // legal parse, but causes a checker error
+// void class { [x?.()] = 1 }       // legal parse, but causes a checker error
+// void class { [new f?.()] = 1 }   // legal parse, but causes a checker error
+void class { [Symbol?.toStringTag] = "" }
+// - property declarations
+void class { a = x?.y }
+void class { a = x?.["y"] }
+void class { a = x?.() }
+void class { a = new x?.() }
+// - heritage clauses
+void class extends M?.y {}
+void class extends M?.["y"] {}
+void class extends M?.z<number> {}
+// - class decorators
+@x?.y class C1 {}
+@x?.["y"] class C2 {}
+@x?.() class C3 {}
+@new x?.() class C4 {}
+// - member decorators
+class C5 { @x?.y m() {} }
+class C6 { @x?.["y"] m() {} } // allowed as ?.[ is not ambiguous with computed property names
+class C7 { @x?.() m() {} }
+class C8 { @new x?.() m () {} }
+// - parameter decorators
+class C9 { m(@x?.y a) {} }
+class C10 { m(@x?.["y"] a) {} }
+class C11 { m(@x?.() a) {} }
+class C12 { m(@new x?.() a) {} }
+
+// functions
+// - parameters
+void function (a = x?.y) {}
+void function (a = x?.["y"]) {}
+void function (a = x?.()) {}
+void function (a = new x?.()) {}
+// - binding elements
+//   - initializers
+void function ({ a = x?.y }) {}
+void function ({ a = x?.["y"] }) {}
+void function ({ a = x?.() }) {}
+void function ({ a = new x?.() }) {}
+//   - computed properties
+void function ({ [x?.y]: a }) {}
+void function ({ [x?.["y"]]: a }) {}
+void function ({ [x?.()]: a }) {}
+void function ({ [new x?.()]: a }) {}
+
+// arrow functions
+// - parameters
+((a = x?.y) => {});
+((a = x?.["y"]) => {});
+((a = x?.()) => {});
+((a = new x?.()) => {});
+// - expression bodies
+(() => x?.y);
+(() => x?.["y"]);
+(() => x?.());
+(() => new x?.());
+
+// parenthesis
+(x?.y);
+
+// comma
+x?.y, f();
+f(), x?.y;
+
+// conditional
+x?.y ? 0 : 1
+0 ? x?.y : 1;
+0 ? 1 : x?.y;
+
+// binary
+x?.y + 1;
+x?.y - 1;
+x?.y * 1;
+x?.y / 1;
+x?.y ** 1;
+x?.y % 1;
+x?.y ^ 1;
+x?.y & 1;
+x?.y | 1;
+x?.y << 1;
+x?.y >> 1;
+x?.y >>> 1;
+x?.y && 1;
+x?.y || 1;
+x?.y == 1;
+x?.y === 1;
+x?.y != 1;
+x?.y !== 1;
+x?.y < 1;
+x?.y <= 1;
+x?.y > 1;
+x?.y >= 1;
+1 + x?.y;
+1 - x?.y;
+1 * x?.y;
+1 / x?.y;
+1 ** x?.y;
+1 % x?.y;
+1 ^ x?.y;
+1 & x?.y;
+1 | x?.y;
+1 << x?.y;
+1 >> x?.y;
+1 >>> x?.y;
+1 && x?.y;
+1 || x?.y;
+1 == x?.y;
+1 === x?.y;
+1 != x?.y;
+1 !== x?.y;
+1 < x?.y;
+1 <= x?.y;
+1 > x?.y;
+1 >= x?.y;
+
+// prefix unary
++x?.y;
+-x?.y;
+!x?.y;
+~x?.y;
+
+// unary
+void x?.y;
+typeof x?.y;
+void function * () { yield x?.y; }
+void async function() { await x?.y; }
+
+// notnull
+x?.y!.z;
+
+// assertions
+<string>x?.y;
+x?.y as string;
+
+// array literals
+[x?.y];
+[, x?.y];
+[...x?.y];
+
+// literals
+1?.toString(); // no need for `..`
+1.?.toString();
+.0?.toString();
+4e3?.toString();
+1.e3?.toString();
+""?.toString();
+''?.toString();
+``?.toString();
+/./?.toString();
+/./g?.toString();
+true?.toString();
+false?.toString();
+
+// templates
+`${x?.y}`;
+
+// variables
+var v = x?.y;
+var [v] = x?.y;
+var [v = x?.y] = [1];
+var {v} = x?.y;
+var {v = x?.y} = {v:1};
+var {[x?.y]: v} = null;
+
+// if/else if
+if (x?.y) {}
+if (1) {} else if (x?.y) {}
+
+// switch
+switch (x?.y) {}
+switch (1) { case x?.y: break; }
+
+// do/while
+do {} while (x?.y)
+while (x?.y) {}
+
+// for
+for (x?.y; x?.y; x?.y);
+
+// for..in
+for (x?.y in {});
+
+// for..of
+for (x?.y of []);
+
+// enums
+enum E {
+    a = x?.y
+}
+
+// @filename: exportsOk.ts
+export default x?.y;

tests/cases/conformance/types/safeNavigation/types.safeNavigation.esnext.1.ts

@@ -0,0 +1,39 @@
+// @target: esnext
+// @lib: esnext
+// @noEmit: true
+// @module: commonjs
+// @strictNullChecks: false
+declare const x1: (() => number) | undefined | null;
+declare const x2: { y: (() => number) | undefined | null; };
+declare const x3: { y: (() => number) | undefined | null; } | undefined | null;
+declare const x4: { y: { z: (() => number) | undefined | null; } };
+declare const x5: { y: { z: (() => number) | undefined | null; } | undefined | null } | undefined | null;
+declare const x6: { y: number } | undefined | null;
+declare const x7: { y: any };
+declare const x8: { y: { z: number } | undefined | null } | undefined | null;
+declare const y: "y";
+declare const z: "z";
+
+x1?.();
+(x1)?.();
+
+x2.y?.();
+x2[y]?.();
+(x2.y)?.();
+(x2[y])?.();
+x3?.y?.();
+x3?.[y]?.();
+
+x4.y.z?.();
+x4.y[z]?.();
+(x4.y.z)?.();
+(x4.y[z])?.();
+x5?.y?.z?.();
+x5?.y?.z;
+x5?.[y]?.[z];
+
+x6?.y = 1;
+x6?.y += 1;
+x6?.y *= 1;
+x6?.y++;
+++x6?.y;

tests/cases/conformance/types/safeNavigation/types.safeNavigation.esnext.2.ts

@@ -0,0 +1,39 @@
+// @target: esnext
+// @lib: esnext
+// @noEmit: true
+// @module: commonjs
+// @strictNullChecks: true
+declare const x1: (() => number) | undefined | null;
+declare const x2: { y: (() => number) | undefined | null; };
+declare const x3: { y: (() => number) | undefined | null; } | undefined | null;
+declare const x4: { y: { z: (() => number) | undefined | null; } };
+declare const x5: { y: { z: (() => number) | undefined | null; } | undefined | null } | undefined | null;
+declare const x6: { y: number } | undefined | null;
+declare const x7: { y: any };
+declare const x8: { y: { z: number } | undefined | null } | undefined | null;
+declare const y: "y";
+declare const z: "z";
+
+const a1 = x1?.();
+const a2 = (x1)?.();
+
+const a3 = x2.y?.();
+const a4 = x2[y]?.();
+const a5 = (x2.y)?.();
+const a6 = (x2[y])?.();
+const a7 = x3?.y?.();
+const a8 = x3?.[y]?.();
+
+const a9 = x4.y.z?.();
+const a10 = x4.y[z]?.();
+const a11 = (x4.y.z)?.();
+const a12 = (x4.y[z])?.();
+const a13 = x5?.y?.z?.();
+const a14 = x5?.y?.z;
+const a15 = x5?.[y]?.[z];
+
+const a16 = x6?.y = 1;
+const a17 = x6?.y += 1;
+const a17a = x6?.y *= 1;
+const a18 = x6?.y++;
+const a19 = ++x6?.y;