diff --git a/package-lock.json b/package-lock.json
index 6e01da81c05..9f76a7acd9c 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -288,9 +288,9 @@
             }
         },
         "@octokit/core": {
-            "version": "3.3.1",
-            "resolved": "https://registry.npmjs.org/@octokit/core/-/core-3.3.1.tgz",
-            "integrity": "sha512-Dc5NNQOYjgZU5S1goN6A/E500yXOfDUFRGQB8/2Tl16AcfvS3H9PudyOe3ZNE/MaVyHPIfC0htReHMJb1tMrvw==",
+            "version": "3.3.2",
+            "resolved": "https://registry.npmjs.org/@octokit/core/-/core-3.3.2.tgz",
+            "integrity": "sha512-Jx83n4tuX/z7QtxnPsAKxXPzH3vANtKmlCB3W3vt18JbkEaBYm+C8dgAlA1FNtqNk3L21pxsKNbWkUQAhiV7ng==",
             "dev": true,
             "requires": {
                 "@octokit/auth-token": "^2.4.4",
@@ -7940,9 +7940,9 @@
             "dev": true
         },
         "uglify-js": {
-            "version": "3.13.2",
-            "resolved": "https://registry.npmjs.org/uglify-js/-/uglify-js-3.13.2.tgz",
-            "integrity": "sha512-SbMu4D2Vo95LMC/MetNaso1194M1htEA+JrqE9Hk+G2DhI+itfS9TRu9ZKeCahLDNa/J3n4MqUJ/fOHMzQpRWw==",
+            "version": "3.13.3",
+            "resolved": "https://registry.npmjs.org/uglify-js/-/uglify-js-3.13.3.tgz",
+            "integrity": "sha512-otIc7O9LyxpUcQoXzj2hL4LPWKklO6LJWoJUzNa8A17Xgi4fOeDC8FBDOLHnC/Slo1CQgsZMcM6as0M76BZaig==",
             "dev": true,
             "optional": true
         },
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index e65d3fcac91..726690dd48f 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -18274,6 +18274,11 @@ namespace ts {
                     }
                 }
                 else if (target.flags & TypeFlags.TemplateLiteral) {
+                    if (source.flags & TypeFlags.TemplateLiteral) {
+                        // Report unreliable variance for type variables referenced in template literal type placeholders.
+                        // For example, `foo-${number}` is related to `foo-${string}` even though number isn't related to string.
+                        instantiateType(source, makeFunctionTypeMapper(reportUnreliableMarkers));
+                    }
                     const result = inferTypesFromTemplateLiteralType(source, target as TemplateLiteralType);
                     if (result && every(result, (r, i) => isValidTypeForTemplateLiteralPlaceholder(r, (target as TemplateLiteralType).types[i]))) {
                         return Ternary.True;
@@ -18318,20 +18323,6 @@ namespace ts {
                         return result;
                     }
                 }
-                else if (source.flags & TypeFlags.TemplateLiteral) {
-                    if (target.flags & TypeFlags.TemplateLiteral &&
-                        (source as TemplateLiteralType).texts.length === (target as TemplateLiteralType).texts.length &&
-                        (source as TemplateLiteralType).types.length === (target as TemplateLiteralType).types.length &&
-                        every((source as TemplateLiteralType).texts, (t, i) => t === (target as TemplateLiteralType).texts[i]) &&
-                        every((instantiateType(source, makeFunctionTypeMapper(reportUnreliableMarkers)) as TemplateLiteralType).types, (t, i) => !!((target as TemplateLiteralType).types[i].flags & (TypeFlags.Any | TypeFlags.String)) || !!isRelatedTo(t, (target as TemplateLiteralType).types[i], /*reportErrors*/ false))) {
-                        return Ternary.True;
-                    }
-                    const constraint = getBaseConstraintOfType(source);
-                    if (constraint && constraint !== source && (result = isRelatedTo(constraint, target, reportErrors))) {
-                        resetErrorInfo(saveErrorInfo);
-                        return result;
-                    }
-                }
                 else if (source.flags & TypeFlags.StringMapping) {
                     if (target.flags & TypeFlags.StringMapping && (<StringMappingType>source).symbol === (<StringMappingType>target).symbol) {
                         if (result = isRelatedTo((<StringMappingType>source).type, (<StringMappingType>target).type, reportErrors)) {
@@ -27125,7 +27116,7 @@ namespace ts {
             if (isInPropertyInitializer(node)
                 && !(isAccessExpression(node) && isAccessExpression(node.expression))
                 && !isBlockScopedNameDeclaredBeforeUse(valueDeclaration, right)
-                && !isPropertyDeclaredInAncestorClass(prop)) {
+                && (compilerOptions.useDefineForClassFields || !isPropertyDeclaredInAncestorClass(prop))) {
                 diagnosticMessage = error(right, Diagnostics.Property_0_is_used_before_its_initialization, declarationName);
             }
             else if (valueDeclaration.kind === SyntaxKind.ClassDeclaration &&
@@ -35254,8 +35245,8 @@ namespace ts {
                 errorAndMaybeSuggestAwait(
                     condExpr,
                     /*maybeMissingAwait*/ true,
-                    Diagnostics.This_condition_will_always_return_0_since_the_types_1_and_2_have_no_overlap,
-                    "true", getTypeNameForErrorDisplay(type), "false");
+                    Diagnostics.This_condition_will_always_return_true_since_this_0_appears_to_always_be_defined,
+                    getTypeNameForErrorDisplay(type));
                 return;
             }
 
@@ -35288,7 +35279,7 @@ namespace ts {
             const isUsed = isBinaryExpression(condExpr.parent) && isFunctionUsedInBinaryExpressionChain(condExpr.parent, testedSymbol)
                 || body && isFunctionUsedInConditionBody(condExpr, body, testedNode, testedSymbol);
             if (!isUsed) {
-                error(location, Diagnostics.This_condition_will_always_return_true_since_the_function_is_always_defined_Did_you_mean_to_call_it_instead);
+                error(location, Diagnostics.This_condition_will_always_return_true_since_this_function_appears_to_always_be_defined_Did_you_mean_to_call_it_instead);
             }
         }
 
@@ -36572,6 +36563,7 @@ namespace ts {
             switch (name.escapedText) {
                 case "any":
                 case "unknown":
+                case "never":
                 case "number":
                 case "bigint":
                 case "boolean":
diff --git a/src/compiler/diagnosticMessages.json b/src/compiler/diagnosticMessages.json
index f7d4fcc84ee..b0d3edd52bd 100644
--- a/src/compiler/diagnosticMessages.json
+++ b/src/compiler/diagnosticMessages.json
@@ -15,7 +15,7 @@
         "category": "Error",
         "code": 1006
     },
-    "The parser expected to find a '}' to match the '{' token here.": {
+    "The parser expected to find a '{1}' to match the '{0}' token here.": {
         "category": "Error",
         "code": 1007
     },
@@ -3168,7 +3168,7 @@
         "category": "Error",
         "code": 2773
     },
-    "This condition will always return true since the function is always defined. Did you mean to call it instead?": {
+    "This condition will always return true since this function appears to always be defined. Did you mean to call it instead?": {
         "category": "Error",
         "code": 2774
     },
@@ -3276,7 +3276,7 @@
         "category": "Error",
         "code": 2800
     },
-    "This condition will always return true since the Promise is always truthy.": {
+    "This condition will always return true since this '{0}' appears to always be defined.": {
         "category": "Error",
         "code": 2801
     },
@@ -3308,6 +3308,10 @@
         "category": "Error",
         "code": 2808
     },
+    "Declaration or statement expected. This '=' follows a block of statements, so if you intended to write a destructuring assignment, you might need to wrap the the whole assignment in parentheses.": {
+        "category": "Error",
+        "code": 2809
+    },
 
     "Import declaration '{0}' is using private name '{1}'.": {
         "category": "Error",
diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index 92d6848d8a9..1d42346123b 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -1335,24 +1335,27 @@ namespace ts {
             return inContext(NodeFlags.AwaitContext);
         }
 
-        function parseErrorAtCurrentToken(message: DiagnosticMessage, arg0?: any): void {
-            parseErrorAt(scanner.getTokenPos(), scanner.getTextPos(), message, arg0);
+        function parseErrorAtCurrentToken(message: DiagnosticMessage, arg0?: any): DiagnosticWithDetachedLocation | undefined {
+            return parseErrorAt(scanner.getTokenPos(), scanner.getTextPos(), message, arg0);
         }
 
-        function parseErrorAtPosition(start: number, length: number, message: DiagnosticMessage, arg0?: any): void {
+        function parseErrorAtPosition(start: number, length: number, message: DiagnosticMessage, arg0?: any): DiagnosticWithDetachedLocation | undefined {
             // Don't report another error if it would just be at the same position as the last error.
             const lastError = lastOrUndefined(parseDiagnostics);
+            let result: DiagnosticWithDetachedLocation | undefined;
             if (!lastError || start !== lastError.start) {
-                parseDiagnostics.push(createDetachedDiagnostic(fileName, start, length, message, arg0));
+                result = createDetachedDiagnostic(fileName, start, length, message, arg0);
+                parseDiagnostics.push(result);
             }
 
             // Mark that we've encountered an error.  We'll set an appropriate bit on the next
             // node we finish so that it can't be reused incrementally.
             parseErrorBeforeNextFinishedNode = true;
+            return result;
         }
 
-        function parseErrorAt(start: number, end: number, message: DiagnosticMessage, arg0?: any): void {
-            parseErrorAtPosition(start, end - start, message, arg0);
+        function parseErrorAt(start: number, end: number, message: DiagnosticMessage, arg0?: any): DiagnosticWithDetachedLocation | undefined {
+            return parseErrorAtPosition(start, end - start, message, arg0);
         }
 
         function parseErrorAtRange(range: TextRange, message: DiagnosticMessage, arg0?: any): void {
@@ -1542,6 +1545,20 @@ namespace ts {
             return false;
         }
 
+        function parseExpectedMatchingBrackets(openKind: SyntaxKind, closeKind: SyntaxKind, openPosition: number) {
+            if (token() === closeKind) {
+                nextToken();
+                return;
+            }
+            const lastError = parseErrorAtCurrentToken(Diagnostics._0_expected, tokenToString(closeKind));
+            if (lastError) {
+                addRelatedInfo(
+                    lastError,
+                    createDetachedDiagnostic(fileName, openPosition, 1, Diagnostics.The_parser_expected_to_find_a_1_to_match_the_0_token_here, tokenToString(openKind), tokenToString(closeKind))
+                );
+            }
+        }
+
         function parseOptional(t: SyntaxKind): boolean {
             if (token() === t) {
                 nextToken();
@@ -2092,8 +2109,7 @@ namespace ts {
 
             while (!isListTerminator(kind)) {
                 if (isListElement(kind, /*inErrorRecovery*/ false)) {
-                    const element = parseListElement(kind, parseElement);
-                    list.push(element);
+                    list.push(parseListElement(kind, parseElement));
 
                     continue;
                 }
@@ -5426,10 +5442,11 @@ namespace ts {
 
         function parseArrayLiteralExpression(): ArrayLiteralExpression {
             const pos = getNodePos();
+            const openBracketPosition = scanner.getTokenPos();
             parseExpected(SyntaxKind.OpenBracketToken);
             const multiLine = scanner.hasPrecedingLineBreak();
             const elements = parseDelimitedList(ParsingContext.ArrayLiteralMembers, parseArgumentOrArrayLiteralElement);
-            parseExpected(SyntaxKind.CloseBracketToken);
+            parseExpectedMatchingBrackets(SyntaxKind.OpenBracketToken, SyntaxKind.CloseBracketToken, openBracketPosition);
             return finishNode(factory.createArrayLiteralExpression(elements, multiLine), pos);
         }
 
@@ -5498,15 +5515,7 @@ namespace ts {
             parseExpected(SyntaxKind.OpenBraceToken);
             const multiLine = scanner.hasPrecedingLineBreak();
             const properties = parseDelimitedList(ParsingContext.ObjectLiteralMembers, parseObjectLiteralElement, /*considerSemicolonAsDelimiter*/ true);
-            if (!parseExpected(SyntaxKind.CloseBraceToken)) {
-                const lastError = lastOrUndefined(parseDiagnostics);
-                if (lastError && lastError.code === Diagnostics._0_expected.code) {
-                    addRelatedInfo(
-                        lastError,
-                        createDetachedDiagnostic(fileName, openBracePosition, 1, Diagnostics.The_parser_expected_to_find_a_to_match_the_token_here)
-                    );
-                }
-            }
+            parseExpectedMatchingBrackets(SyntaxKind.OpenBraceToken, SyntaxKind.CloseBraceToken, openBracePosition);
             return finishNode(factory.createObjectLiteralExpression(properties, multiLine), pos);
         }
 
@@ -5591,16 +5600,14 @@ namespace ts {
             if (parseExpected(SyntaxKind.OpenBraceToken, diagnosticMessage) || ignoreMissingOpenBrace) {
                 const multiLine = scanner.hasPrecedingLineBreak();
                 const statements = parseList(ParsingContext.BlockStatements, parseStatement);
-                if (!parseExpected(SyntaxKind.CloseBraceToken)) {
-                    const lastError = lastOrUndefined(parseDiagnostics);
-                    if (lastError && lastError.code === Diagnostics._0_expected.code) {
-                        addRelatedInfo(
-                            lastError,
-                            createDetachedDiagnostic(fileName, openBracePosition, 1, Diagnostics.The_parser_expected_to_find_a_to_match_the_token_here)
-                        );
-                    }
+                parseExpectedMatchingBrackets(SyntaxKind.OpenBraceToken, SyntaxKind.CloseBraceToken, openBracePosition);
+                const result = finishNode(factory.createBlock(statements, multiLine), pos);
+                if (token() === SyntaxKind.EqualsToken) {
+                    parseErrorAtCurrentToken(Diagnostics.Declaration_or_statement_expected_This_follows_a_block_of_statements_so_if_you_intended_to_write_a_destructuring_assignment_you_might_need_to_wrap_the_the_whole_assignment_in_parentheses);
+                    nextToken();
                 }
-                return finishNode(factory.createBlock(statements, multiLine), pos);
+
+                return result;
             }
             else {
                 const statements = createMissingList<Statement>();
@@ -5647,9 +5654,10 @@ namespace ts {
         function parseIfStatement(): IfStatement {
             const pos = getNodePos();
             parseExpected(SyntaxKind.IfKeyword);
+            const openParenPosition = scanner.getTokenPos();
             parseExpected(SyntaxKind.OpenParenToken);
             const expression = allowInAnd(parseExpression);
-            parseExpected(SyntaxKind.CloseParenToken);
+            parseExpectedMatchingBrackets(SyntaxKind.OpenParenToken, SyntaxKind.CloseParenToken, openParenPosition);
             const thenStatement = parseStatement();
             const elseStatement = parseOptional(SyntaxKind.ElseKeyword) ? parseStatement() : undefined;
             return finishNode(factory.createIfStatement(expression, thenStatement, elseStatement), pos);
@@ -5660,9 +5668,10 @@ namespace ts {
             parseExpected(SyntaxKind.DoKeyword);
             const statement = parseStatement();
             parseExpected(SyntaxKind.WhileKeyword);
+            const openParenPosition = scanner.getTokenPos();
             parseExpected(SyntaxKind.OpenParenToken);
             const expression = allowInAnd(parseExpression);
-            parseExpected(SyntaxKind.CloseParenToken);
+            parseExpectedMatchingBrackets(SyntaxKind.OpenParenToken, SyntaxKind.CloseParenToken, openParenPosition);
 
             // From: https://mail.mozilla.org/pipermail/es-discuss/2011-August/016188.html
             // 157 min --- All allen at wirfs-brock.com CONF --- "do{;}while(false)false" prohibited in
@@ -5675,9 +5684,10 @@ namespace ts {
         function parseWhileStatement(): WhileStatement {
             const pos = getNodePos();
             parseExpected(SyntaxKind.WhileKeyword);
+            const openParenPosition = scanner.getTokenPos();
             parseExpected(SyntaxKind.OpenParenToken);
             const expression = allowInAnd(parseExpression);
-            parseExpected(SyntaxKind.CloseParenToken);
+            parseExpectedMatchingBrackets(SyntaxKind.OpenParenToken, SyntaxKind.CloseParenToken, openParenPosition);
             const statement = parseStatement();
             return finishNode(factory.createWhileStatement(expression, statement), pos);
         }
@@ -5749,9 +5759,10 @@ namespace ts {
         function parseWithStatement(): WithStatement {
             const pos = getNodePos();
             parseExpected(SyntaxKind.WithKeyword);
+            const openParenPosition = scanner.getTokenPos();
             parseExpected(SyntaxKind.OpenParenToken);
             const expression = allowInAnd(parseExpression);
-            parseExpected(SyntaxKind.CloseParenToken);
+            parseExpectedMatchingBrackets(SyntaxKind.OpenParenToken, SyntaxKind.CloseParenToken, openParenPosition);
             const statement = doInsideOfContext(NodeFlags.InWithStatement, parseStatement);
             return finishNode(factory.createWithStatement(expression, statement), pos);
         }
@@ -7973,13 +7984,9 @@ namespace ts {
                             hasChildren = true;
                             if (child.kind === SyntaxKind.JSDocTypeTag) {
                                 if (childTypeTag) {
-                                    parseErrorAtCurrentToken(Diagnostics.A_JSDoc_typedef_comment_may_not_contain_multiple_type_tags);
-                                    const lastError = lastOrUndefined(parseDiagnostics);
+                                    const lastError = parseErrorAtCurrentToken(Diagnostics.A_JSDoc_typedef_comment_may_not_contain_multiple_type_tags);
                                     if (lastError) {
-                                        addRelatedInfo(
-                                            lastError,
-                                            createDetachedDiagnostic(fileName, 0, 0, Diagnostics.The_tag_was_first_specified_here)
-                                        );
+                                        addRelatedInfo(lastError, createDetachedDiagnostic(fileName, 0, 0, Diagnostics.The_tag_was_first_specified_here));
                                     }
                                     break;
                                 }
@@ -8011,7 +8018,7 @@ namespace ts {
                     }
 
                     const typedefTag = factory.createJSDocTypedefTag(tagName, typeExpression, fullName, comment);
-                    return finishNode(typedefTag, start);
+                    return finishNode(typedefTag, start, end);
                 }
 
                 function parseJSDocTypeNameWithNamespace(nested?: boolean) {
diff --git a/src/compiler/tsbuildPublic.ts b/src/compiler/tsbuildPublic.ts
index ddebecc2e55..d642f79a124 100644
--- a/src/compiler/tsbuildPublic.ts
+++ b/src/compiler/tsbuildPublic.ts
@@ -1717,7 +1717,11 @@ namespace ts {
                 continue;
             }
             const outputs = getAllProjectOutputs(parsed, !host.useCaseSensitiveFileNames());
+            if (!outputs.length) continue;
+            const inputFileNames = new Set(parsed.fileNames.map(f => toPath(state, f)));
             for (const output of outputs) {
+                // If output name is same as input file name, do not delete and ignore the error
+                if (inputFileNames.has(toPath(state, output))) continue;
                 if (host.fileExists(output)) {
                     if (filesToDelete) {
                         filesToDelete.push(output);
diff --git a/src/harness/compilerImpl.ts b/src/harness/compilerImpl.ts
index 0d24ee4797f..badab5c6cbc 100644
--- a/src/harness/compilerImpl.ts
+++ b/src/harness/compilerImpl.ts
@@ -135,8 +135,6 @@ namespace compiler {
                     }
                 }
             }
-
-            this.diagnostics = diagnostics;
         }
 
         public get vfs(): vfs.FileSystem {
diff --git a/src/lib/es5.d.ts b/src/lib/es5.d.ts
index b8ae7ca57ef..bfa5241a84d 100644
--- a/src/lib/es5.d.ts
+++ b/src/lib/es5.d.ts
@@ -1073,7 +1073,7 @@ interface ReadonlyArray<T> {
      */
     toString(): string;
     /**
-     * Returns a string representation of an array. The elements are converted to string using their toLocalString methods.
+     * Returns a string representation of an array. The elements are converted to string using their toLocaleString methods.
      */
     toLocaleString(): string;
     /**
@@ -1207,7 +1207,7 @@ interface Array<T> {
      */
     toString(): string;
     /**
-     * Returns a string representation of an array. The elements are converted to string using their toLocalString methods.
+     * Returns a string representation of an array. The elements are converted to string using their toLocaleString methods.
      */
     toLocaleString(): string;
     /**
diff --git a/src/services/codefixes/addMissingAwait.ts b/src/services/codefixes/addMissingAwait.ts
index 1b16a33deb3..a31bf50f46e 100644
--- a/src/services/codefixes/addMissingAwait.ts
+++ b/src/services/codefixes/addMissingAwait.ts
@@ -14,6 +14,7 @@ namespace ts.codefix {
         Diagnostics.Operator_0_cannot_be_applied_to_type_1.code,
         Diagnostics.Operator_0_cannot_be_applied_to_types_1_and_2.code,
         Diagnostics.This_condition_will_always_return_0_since_the_types_1_and_2_have_no_overlap.code,
+        Diagnostics.This_condition_will_always_return_true_since_this_0_appears_to_always_be_defined.code,
         Diagnostics.Type_0_is_not_an_array_type.code,
         Diagnostics.Type_0_is_not_an_array_type_or_a_string_type.code,
         Diagnostics.Type_0_is_not_an_array_type_or_a_string_type_Use_compiler_option_downlevelIteration_to_allow_iterating_of_iterators.code,
diff --git a/src/services/codefixes/convertToEs6Module.ts b/src/services/codefixes/convertToEs6Module.ts
index 963f8923ee6..e15c507a4ef 100644
--- a/src/services/codefixes/convertToEs6Module.ts
+++ b/src/services/codefixes/convertToEs6Module.ts
@@ -436,7 +436,9 @@ namespace ts.codefix {
 
     /**
      * Convert `import x = require("x").`
-     * Also converts uses like `x.y()` to `y()` and uses a named import.
+     * Also:
+     * - Convert `x.default()` to `x()` to handle ES6 default export
+     * - Converts uses like `x.y()` to `y()` and uses a named import.
      */
     function convertSingleIdentifierImport(name: Identifier, moduleSpecifier: StringLiteralLike, checker: TypeChecker, identifiers: Identifiers, quotePreference: QuotePreference): ConvertedImports {
         const nameSymbol = checker.getSymbolAtLocation(name);
@@ -454,15 +456,23 @@ namespace ts.codefix {
 
             const { parent } = use;
             if (isPropertyAccessExpression(parent)) {
-                const { expression, name: { text: propertyName } } = parent;
-                Debug.assert(expression === use, "Didn't expect expression === use"); // Else shouldn't have been in `collectIdentifiers`
-                let idName = namedBindingsNames.get(propertyName);
-                if (idName === undefined) {
-                    idName = makeUniqueName(propertyName, identifiers);
-                    namedBindingsNames.set(propertyName, idName);
-                }
+                const { name: { text: propertyName } } = parent;
+                if (propertyName === "default") {
+                    needDefaultImport = true;
 
-                (useSitesToUnqualify ??= new Map()).set(parent, factory.createIdentifier(idName));
+                    const importDefaultName = use.getText();
+                    (useSitesToUnqualify ??= new Map()).set(parent, factory.createIdentifier(importDefaultName));
+                }
+                else {
+                    Debug.assert(parent.expression === use, "Didn't expect expression === use"); // Else shouldn't have been in `collectIdentifiers`
+                    let idName = namedBindingsNames.get(propertyName);
+                    if (idName === undefined) {
+                        idName = makeUniqueName(propertyName, identifiers);
+                        namedBindingsNames.set(propertyName, idName);
+                    }
+
+                    (useSitesToUnqualify ??= new Map()).set(parent, factory.createIdentifier(idName));
+                }
             }
             else {
                 needDefaultImport = true;
diff --git a/src/services/codefixes/fixMissingCallParentheses.ts b/src/services/codefixes/fixMissingCallParentheses.ts
index a144bc40f50..042f7b506c7 100644
--- a/src/services/codefixes/fixMissingCallParentheses.ts
+++ b/src/services/codefixes/fixMissingCallParentheses.ts
@@ -2,7 +2,7 @@
 namespace ts.codefix {
     const fixId = "fixMissingCallParentheses";
     const errorCodes = [
-        Diagnostics.This_condition_will_always_return_true_since_the_function_is_always_defined_Did_you_mean_to_call_it_instead.code,
+        Diagnostics.This_condition_will_always_return_true_since_this_function_appears_to_always_be_defined_Did_you_mean_to_call_it_instead.code,
     ];
 
     registerCodeFix({
diff --git a/src/services/utilities.ts b/src/services/utilities.ts
index d4662783d87..f398afc46c0 100644
--- a/src/services/utilities.ts
+++ b/src/services/utilities.ts
@@ -2516,8 +2516,10 @@ namespace ts {
     }
 
     /* @internal */
-    export function needsParentheses(expression: Expression) {
-        return isBinaryExpression(expression) && expression.operatorToken.kind === SyntaxKind.CommaToken || isObjectLiteralExpression(expression);
+    export function needsParentheses(expression: Expression): boolean {
+        return isBinaryExpression(expression) && expression.operatorToken.kind === SyntaxKind.CommaToken
+            || isObjectLiteralExpression(expression)
+            || isAsExpression(expression) && isObjectLiteralExpression(expression.expression);
     }
 
     export function getContextualTypeFromParent(node: Expression, checker: TypeChecker): Type | undefined {
diff --git a/src/testRunner/tsconfig.json b/src/testRunner/tsconfig.json
index 34c55d0d5da..bf372efb81c 100644
--- a/src/testRunner/tsconfig.json
+++ b/src/testRunner/tsconfig.json
@@ -113,6 +113,7 @@
         "unittests/services/textChanges.ts",
         "unittests/services/transpile.ts",
         "unittests/tsbuild/amdModulesWithOut.ts",
+        "unittests/tsbuild/clean.ts",
         "unittests/tsbuild/configFileErrors.ts",
         "unittests/tsbuild/configFileExtends.ts",
         "unittests/tsbuild/containerOnlyReferenced.ts",
diff --git a/src/testRunner/unittests/tsbuild/clean.ts b/src/testRunner/unittests/tsbuild/clean.ts
new file mode 100644
index 00000000000..90bb2985290
--- /dev/null
+++ b/src/testRunner/unittests/tsbuild/clean.ts
@@ -0,0 +1,16 @@
+namespace ts {
+    describe("unittests:: tsbuild - clean", () => {
+        verifyTsc({
+            scenario: "clean",
+            subScenario: `file name and output name clashing`,
+            commandLineArgs: ["--b", "/src/tsconfig.json", "-clean"],
+            fs: () => loadProjectFromFiles({
+                "/src/index.js": "",
+                "/src/bar.ts": "",
+                "/src/tsconfig.json": JSON.stringify({
+                    compilerOptions: { allowJs: true },
+                }),
+            }),
+        });
+    });
+}
\ No newline at end of file
diff --git a/tests/baselines/reference/assignmentLHSIsValue.errors.txt b/tests/baselines/reference/assignmentLHSIsValue.errors.txt
index 1cf07b81622..71809b4605f 100644
--- a/tests/baselines/reference/assignmentLHSIsValue.errors.txt
+++ b/tests/baselines/reference/assignmentLHSIsValue.errors.txt
@@ -13,14 +13,15 @@ tests/cases/conformance/expressions/assignmentOperator/assignmentLHSIsValue.ts(2
 tests/cases/conformance/expressions/assignmentOperator/assignmentLHSIsValue.ts(30,1): error TS2364: The left-hand side of an assignment expression must be a variable or a property access.
 tests/cases/conformance/expressions/assignmentOperator/assignmentLHSIsValue.ts(31,1): error TS2364: The left-hand side of an assignment expression must be a variable or a property access.
 tests/cases/conformance/expressions/assignmentOperator/assignmentLHSIsValue.ts(32,1): error TS2364: The left-hand side of an assignment expression must be a variable or a property access.
-tests/cases/conformance/expressions/assignmentOperator/assignmentLHSIsValue.ts(35,9): error TS1128: Declaration or statement expected.
+tests/cases/conformance/expressions/assignmentOperator/assignmentLHSIsValue.ts(35,9): error TS2809: Declaration or statement expected. This '=' follows a block of statements, so if you intended to write a destructuring assignment, you might need to wrap the the whole assignment in parentheses.
 tests/cases/conformance/expressions/assignmentOperator/assignmentLHSIsValue.ts(38,2): error TS2364: The left-hand side of an assignment expression must be a variable or a property access.
 tests/cases/conformance/expressions/assignmentOperator/assignmentLHSIsValue.ts(38,6): error TS2364: The left-hand side of an assignment expression must be a variable or a property access.
 tests/cases/conformance/expressions/assignmentOperator/assignmentLHSIsValue.ts(42,36): error TS1034: 'super' must be followed by an argument list or member access.
 tests/cases/conformance/expressions/assignmentOperator/assignmentLHSIsValue.ts(44,19): error TS1034: 'super' must be followed by an argument list or member access.
 tests/cases/conformance/expressions/assignmentOperator/assignmentLHSIsValue.ts(46,27): error TS1034: 'super' must be followed by an argument list or member access.
-tests/cases/conformance/expressions/assignmentOperator/assignmentLHSIsValue.ts(50,20): error TS1128: Declaration or statement expected.
-tests/cases/conformance/expressions/assignmentOperator/assignmentLHSIsValue.ts(51,11): error TS1005: ';' expected.
+tests/cases/conformance/expressions/assignmentOperator/assignmentLHSIsValue.ts(50,20): error TS2809: Declaration or statement expected. This '=' follows a block of statements, so if you intended to write a destructuring assignment, you might need to wrap the the whole assignment in parentheses.
+tests/cases/conformance/expressions/assignmentOperator/assignmentLHSIsValue.ts(51,11): error TS2809: Declaration or statement expected. This '=' follows a block of statements, so if you intended to write a destructuring assignment, you might need to wrap the the whole assignment in parentheses.
+tests/cases/conformance/expressions/assignmentOperator/assignmentLHSIsValue.ts(51,13): error TS1005: ';' expected.
 tests/cases/conformance/expressions/assignmentOperator/assignmentLHSIsValue.ts(54,1): error TS2364: The left-hand side of an assignment expression must be a variable or a property access.
 tests/cases/conformance/expressions/assignmentOperator/assignmentLHSIsValue.ts(57,1): error TS2364: The left-hand side of an assignment expression must be a variable or a property access.
 tests/cases/conformance/expressions/assignmentOperator/assignmentLHSIsValue.ts(58,2): error TS2631: Cannot assign to 'M' because it is a namespace.
@@ -38,7 +39,7 @@ tests/cases/conformance/expressions/assignmentOperator/assignmentLHSIsValue.ts(6
 tests/cases/conformance/expressions/assignmentOperator/assignmentLHSIsValue.ts(70,1): error TS2364: The left-hand side of an assignment expression must be a variable or a property access.
 
 
-==== tests/cases/conformance/expressions/assignmentOperator/assignmentLHSIsValue.ts (38 errors) ====
+==== tests/cases/conformance/expressions/assignmentOperator/assignmentLHSIsValue.ts (39 errors) ====
     // expected error for all the LHS of assignments
     var value: any;
     
@@ -105,7 +106,7 @@ tests/cases/conformance/expressions/assignmentOperator/assignmentLHSIsValue.ts(7
     // object literals
     { a: 0} = value;
             ~
-!!! error TS1128: Declaration or statement expected.
+!!! error TS2809: Declaration or statement expected. This '=' follows a block of statements, so if you intended to write a destructuring assignment, you might need to wrap the the whole assignment in parentheses.
     
     // array literals
     ['', ''] = value;
@@ -132,9 +133,11 @@ tests/cases/conformance/expressions/assignmentOperator/assignmentLHSIsValue.ts(7
     // function expression
     function bar() { } = value;
                        ~
-!!! error TS1128: Declaration or statement expected.
+!!! error TS2809: Declaration or statement expected. This '=' follows a block of statements, so if you intended to write a destructuring assignment, you might need to wrap the the whole assignment in parentheses.
     () => { } = value;
               ~
+!!! error TS2809: Declaration or statement expected. This '=' follows a block of statements, so if you intended to write a destructuring assignment, you might need to wrap the the whole assignment in parentheses.
+                ~~~~~
 !!! error TS1005: ';' expected.
     
     // function calls
diff --git a/tests/baselines/reference/assignmentLHSIsValue.types b/tests/baselines/reference/assignmentLHSIsValue.types
index 82dd7f026ad..ad4905acc94 100644
--- a/tests/baselines/reference/assignmentLHSIsValue.types
+++ b/tests/baselines/reference/assignmentLHSIsValue.types
@@ -146,7 +146,7 @@ function bar() { } = value;
 >value : any
 
 () => { } = value;
->() => { } : () => void
+>() => { } = : () => void
 >value : any
 
 // function calls
diff --git a/tests/baselines/reference/completionEntryForUnionMethod.baseline b/tests/baselines/reference/completionEntryForUnionMethod.baseline
index ce000ec6ddb..858d356be23 100644
--- a/tests/baselines/reference/completionEntryForUnionMethod.baseline
+++ b/tests/baselines/reference/completionEntryForUnionMethod.baseline
@@ -223,7 +223,7 @@
           ],
           "documentation": [
             {
-              "text": "Returns a string representation of an array. The elements are converted to string using their toLocalString methods.",
+              "text": "Returns a string representation of an array. The elements are converted to string using their toLocaleString methods.",
               "kind": "text"
             }
           ]
diff --git a/tests/baselines/reference/constructorWithIncompleteTypeAnnotation.errors.txt b/tests/baselines/reference/constructorWithIncompleteTypeAnnotation.errors.txt
index c8af0683007..4e866e9e9e8 100644
--- a/tests/baselines/reference/constructorWithIncompleteTypeAnnotation.errors.txt
+++ b/tests/baselines/reference/constructorWithIncompleteTypeAnnotation.errors.txt
@@ -121,6 +121,7 @@ tests/cases/compiler/constructorWithIncompleteTypeAnnotation.ts(261,1): error TS
                     if (retValue != 0 ^=  {
                                       ~~
 !!! error TS1005: ')' expected.
+!!! related TS1007 tests/cases/compiler/constructorWithIncompleteTypeAnnotation.ts:22:20: The parser expected to find a ')' to match the '(' token here.
                                           ~
     
     
diff --git a/tests/baselines/reference/destructionAssignmentError.errors.txt b/tests/baselines/reference/destructionAssignmentError.errors.txt
new file mode 100644
index 00000000000..831f9a5fc6c
--- /dev/null
+++ b/tests/baselines/reference/destructionAssignmentError.errors.txt
@@ -0,0 +1,27 @@
+tests/cases/compiler/destructionAssignmentError.ts(6,3): error TS2695: Left side of comma operator is unused and has no side effects.
+tests/cases/compiler/destructionAssignmentError.ts(6,10): error TS2809: Declaration or statement expected. This '=' follows a block of statements, so if you intended to write a destructuring assignment, you might need to wrap the the whole assignment in parentheses.
+tests/cases/compiler/destructionAssignmentError.ts(11,3): error TS2695: Left side of comma operator is unused and has no side effects.
+tests/cases/compiler/destructionAssignmentError.ts(12,1): error TS2809: Declaration or statement expected. This '=' follows a block of statements, so if you intended to write a destructuring assignment, you might need to wrap the the whole assignment in parentheses.
+
+
+==== tests/cases/compiler/destructionAssignmentError.ts (4 errors) ====
+    declare function fn(): { a: 1, b: 2 }
+    let a: number;
+    let b: number;
+    
+    ({ a, b } = fn());
+    { a, b } = fn();
+      ~
+!!! error TS2695: Left side of comma operator is unused and has no side effects.
+             ~
+!!! error TS2809: Declaration or statement expected. This '=' follows a block of statements, so if you intended to write a destructuring assignment, you might need to wrap the the whole assignment in parentheses.
+    
+    ({ a, b } =
+    fn());
+    
+    { a, b }
+      ~
+!!! error TS2695: Left side of comma operator is unused and has no side effects.
+    = fn();
+    ~
+!!! error TS2809: Declaration or statement expected. This '=' follows a block of statements, so if you intended to write a destructuring assignment, you might need to wrap the the whole assignment in parentheses.
\ No newline at end of file
diff --git a/tests/baselines/reference/destructionAssignmentError.js b/tests/baselines/reference/destructionAssignmentError.js
new file mode 100644
index 00000000000..f188ccc1daa
--- /dev/null
+++ b/tests/baselines/reference/destructionAssignmentError.js
@@ -0,0 +1,28 @@
+//// [destructionAssignmentError.ts]
+declare function fn(): { a: 1, b: 2 }
+let a: number;
+let b: number;
+
+({ a, b } = fn());
+{ a, b } = fn();
+
+({ a, b } =
+fn());
+
+{ a, b }
+= fn();
+
+//// [destructionAssignmentError.js]
+var _a, _b;
+var a;
+var b;
+(_a = fn(), a = _a.a, b = _a.b);
+{
+    a, b;
+}
+fn();
+(_b = fn(), a = _b.a, b = _b.b);
+{
+    a, b;
+}
+fn();
diff --git a/tests/baselines/reference/destructionAssignmentError.symbols b/tests/baselines/reference/destructionAssignmentError.symbols
new file mode 100644
index 00000000000..82650703289
--- /dev/null
+++ b/tests/baselines/reference/destructionAssignmentError.symbols
@@ -0,0 +1,36 @@
+=== tests/cases/compiler/destructionAssignmentError.ts ===
+declare function fn(): { a: 1, b: 2 }
+>fn : Symbol(fn, Decl(destructionAssignmentError.ts, 0, 0))
+>a : Symbol(a, Decl(destructionAssignmentError.ts, 0, 24))
+>b : Symbol(b, Decl(destructionAssignmentError.ts, 0, 30))
+
+let a: number;
+>a : Symbol(a, Decl(destructionAssignmentError.ts, 1, 3))
+
+let b: number;
+>b : Symbol(b, Decl(destructionAssignmentError.ts, 2, 3))
+
+({ a, b } = fn());
+>a : Symbol(a, Decl(destructionAssignmentError.ts, 4, 2))
+>b : Symbol(b, Decl(destructionAssignmentError.ts, 4, 5))
+>fn : Symbol(fn, Decl(destructionAssignmentError.ts, 0, 0))
+
+{ a, b } = fn();
+>a : Symbol(a, Decl(destructionAssignmentError.ts, 1, 3))
+>b : Symbol(b, Decl(destructionAssignmentError.ts, 2, 3))
+>fn : Symbol(fn, Decl(destructionAssignmentError.ts, 0, 0))
+
+({ a, b } =
+>a : Symbol(a, Decl(destructionAssignmentError.ts, 7, 2))
+>b : Symbol(b, Decl(destructionAssignmentError.ts, 7, 5))
+
+fn());
+>fn : Symbol(fn, Decl(destructionAssignmentError.ts, 0, 0))
+
+{ a, b }
+>a : Symbol(a, Decl(destructionAssignmentError.ts, 1, 3))
+>b : Symbol(b, Decl(destructionAssignmentError.ts, 2, 3))
+
+= fn();
+>fn : Symbol(fn, Decl(destructionAssignmentError.ts, 0, 0))
+
diff --git a/tests/baselines/reference/destructionAssignmentError.types b/tests/baselines/reference/destructionAssignmentError.types
new file mode 100644
index 00000000000..94cbd3f792f
--- /dev/null
+++ b/tests/baselines/reference/destructionAssignmentError.types
@@ -0,0 +1,48 @@
+=== tests/cases/compiler/destructionAssignmentError.ts ===
+declare function fn(): { a: 1, b: 2 }
+>fn : () => {    a: 1;    b: 2;}
+>a : 1
+>b : 2
+
+let a: number;
+>a : number
+
+let b: number;
+>b : number
+
+({ a, b } = fn());
+>({ a, b } = fn()) : { a: 1; b: 2; }
+>{ a, b } = fn() : { a: 1; b: 2; }
+>{ a, b } : { a: number; b: number; }
+>a : number
+>b : number
+>fn() : { a: 1; b: 2; }
+>fn : () => { a: 1; b: 2; }
+
+{ a, b } = fn();
+>a, b : number
+>a : number
+>b : number
+>fn() : { a: 1; b: 2; }
+>fn : () => { a: 1; b: 2; }
+
+({ a, b } =
+>({ a, b } =fn()) : { a: 1; b: 2; }
+>{ a, b } =fn() : { a: 1; b: 2; }
+>{ a, b } : { a: number; b: number; }
+>a : number
+>b : number
+
+fn());
+>fn() : { a: 1; b: 2; }
+>fn : () => { a: 1; b: 2; }
+
+{ a, b }
+>a, b : number
+>a : number
+>b : number
+
+= fn();
+>fn() : { a: 1; b: 2; }
+>fn : () => { a: 1; b: 2; }
+
diff --git a/tests/baselines/reference/errorRecoveryWithDotFollowedByNamespaceKeyword.errors.txt b/tests/baselines/reference/errorRecoveryWithDotFollowedByNamespaceKeyword.errors.txt
index 3a7c89e2f41..6bac6729147 100644
--- a/tests/baselines/reference/errorRecoveryWithDotFollowedByNamespaceKeyword.errors.txt
+++ b/tests/baselines/reference/errorRecoveryWithDotFollowedByNamespaceKeyword.errors.txt
@@ -16,5 +16,4 @@ tests/cases/compiler/errorRecoveryWithDotFollowedByNamespaceKeyword.ts(9,2): err
     }
      
 !!! error TS1005: '}' expected.
-!!! related TS1007 tests/cases/compiler/errorRecoveryWithDotFollowedByNamespaceKeyword.ts:3:19: The parser expected to find a '}' to match the '{' token here.
-!!! related TS1007 tests/cases/compiler/errorRecoveryWithDotFollowedByNamespaceKeyword.ts:2:20: The parser expected to find a '}' to match the '{' token here.
\ No newline at end of file
+!!! related TS1007 tests/cases/compiler/errorRecoveryWithDotFollowedByNamespaceKeyword.ts:3:19: The parser expected to find a '}' to match the '{' token here.
\ No newline at end of file
diff --git a/tests/baselines/reference/interfacesWithPredefinedTypesAsNames.errors.txt b/tests/baselines/reference/interfacesWithPredefinedTypesAsNames.errors.txt
index 1925079095a..d6ad166fb0f 100644
--- a/tests/baselines/reference/interfacesWithPredefinedTypesAsNames.errors.txt
+++ b/tests/baselines/reference/interfacesWithPredefinedTypesAsNames.errors.txt
@@ -4,9 +4,11 @@ tests/cases/conformance/interfaces/interfaceDeclarations/interfacesWithPredefine
 tests/cases/conformance/interfaces/interfaceDeclarations/interfacesWithPredefinedTypesAsNames.ts(4,11): error TS2427: Interface name cannot be 'boolean'.
 tests/cases/conformance/interfaces/interfaceDeclarations/interfacesWithPredefinedTypesAsNames.ts(5,1): error TS2304: Cannot find name 'interface'.
 tests/cases/conformance/interfaces/interfaceDeclarations/interfacesWithPredefinedTypesAsNames.ts(5,11): error TS1005: ';' expected.
+tests/cases/conformance/interfaces/interfaceDeclarations/interfacesWithPredefinedTypesAsNames.ts(6,11): error TS2427: Interface name cannot be 'unknown'.
+tests/cases/conformance/interfaces/interfaceDeclarations/interfacesWithPredefinedTypesAsNames.ts(7,11): error TS2427: Interface name cannot be 'never'.
 
 
-==== tests/cases/conformance/interfaces/interfaceDeclarations/interfacesWithPredefinedTypesAsNames.ts (6 errors) ====
+==== tests/cases/conformance/interfaces/interfaceDeclarations/interfacesWithPredefinedTypesAsNames.ts (8 errors) ====
     interface any { }
               ~~~
 !!! error TS2427: Interface name cannot be 'any'.
@@ -23,4 +25,10 @@ tests/cases/conformance/interfaces/interfaceDeclarations/interfacesWithPredefine
     ~~~~~~~~~
 !!! error TS2304: Cannot find name 'interface'.
               ~~~~
-!!! error TS1005: ';' expected.
\ No newline at end of file
+!!! error TS1005: ';' expected.
+    interface unknown {}
+              ~~~~~~~
+!!! error TS2427: Interface name cannot be 'unknown'.
+    interface never {}
+              ~~~~~
+!!! error TS2427: Interface name cannot be 'never'.
\ No newline at end of file
diff --git a/tests/baselines/reference/interfacesWithPredefinedTypesAsNames.js b/tests/baselines/reference/interfacesWithPredefinedTypesAsNames.js
index ca186b1cef1..2bb4f0be112 100644
--- a/tests/baselines/reference/interfacesWithPredefinedTypesAsNames.js
+++ b/tests/baselines/reference/interfacesWithPredefinedTypesAsNames.js
@@ -3,7 +3,9 @@ interface any { }
 interface number { }
 interface string { }
 interface boolean { }
-interface void {}
+interface void {}
+interface unknown {}
+interface never {}
 
 //// [interfacesWithPredefinedTypesAsNames.js]
 interface;
diff --git a/tests/baselines/reference/interfacesWithPredefinedTypesAsNames.symbols b/tests/baselines/reference/interfacesWithPredefinedTypesAsNames.symbols
index f469eaba590..c79493530ea 100644
--- a/tests/baselines/reference/interfacesWithPredefinedTypesAsNames.symbols
+++ b/tests/baselines/reference/interfacesWithPredefinedTypesAsNames.symbols
@@ -12,3 +12,9 @@ interface boolean { }
 >boolean : Symbol(boolean, Decl(interfacesWithPredefinedTypesAsNames.ts, 2, 20))
 
 interface void {}
+interface unknown {}
+>unknown : Symbol(unknown, Decl(interfacesWithPredefinedTypesAsNames.ts, 4, 17))
+
+interface never {}
+>never : Symbol(never, Decl(interfacesWithPredefinedTypesAsNames.ts, 5, 20))
+
diff --git a/tests/baselines/reference/interfacesWithPredefinedTypesAsNames.types b/tests/baselines/reference/interfacesWithPredefinedTypesAsNames.types
index 9d6b22cfa48..492facdc845 100644
--- a/tests/baselines/reference/interfacesWithPredefinedTypesAsNames.types
+++ b/tests/baselines/reference/interfacesWithPredefinedTypesAsNames.types
@@ -8,3 +8,5 @@ interface void {}
 >void {} : undefined
 >{} : {}
 
+interface unknown {}
+interface never {}
diff --git a/tests/baselines/reference/jsDeclarationsParameterTagReusesInputNodeInEmit1.errors.txt b/tests/baselines/reference/jsDeclarationsParameterTagReusesInputNodeInEmit1.errors.txt
index 6d2f34fcc58..4a258fc96bd 100644
--- a/tests/baselines/reference/jsDeclarationsParameterTagReusesInputNodeInEmit1.errors.txt
+++ b/tests/baselines/reference/jsDeclarationsParameterTagReusesInputNodeInEmit1.errors.txt
@@ -18,7 +18,7 @@ tests/cases/conformance/jsdoc/declarations/file.js(6,5): error TS4084: Exported
     
 ==== tests/cases/conformance/jsdoc/declarations/file.js (3 errors) ====
     /** @typedef {import('./base')} BaseFactory */
-        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 !!! error TS4084: Exported type alias 'BaseFactory' has or is using private name 'Base' from module "tests/cases/conformance/jsdoc/declarations/base".
     /**
      * @callback BaseFactoryFactory
diff --git a/tests/baselines/reference/jsDocSignature-43394.baseline b/tests/baselines/reference/jsDocSignature-43394.baseline
new file mode 100644
index 00000000000..905b7e8bccc
--- /dev/null
+++ b/tests/baselines/reference/jsDocSignature-43394.baseline
@@ -0,0 +1,9 @@
+[
+  {
+    "marker": {
+      "fileName": "/tests/cases/fourslash/jsDocSignature-43394.ts",
+      "position": 58,
+      "name": ""
+    }
+  }
+]
\ No newline at end of file
diff --git a/tests/baselines/reference/missingCloseBracketInArray.errors.txt b/tests/baselines/reference/missingCloseBracketInArray.errors.txt
new file mode 100644
index 00000000000..26801c02812
--- /dev/null
+++ b/tests/baselines/reference/missingCloseBracketInArray.errors.txt
@@ -0,0 +1,8 @@
+tests/cases/compiler/missingCloseBracketInArray.ts(1,48): error TS1005: ']' expected.
+
+
+==== tests/cases/compiler/missingCloseBracketInArray.ts (1 errors) ====
+    var alphas:string[] = alphas = ["1","2","3","4"
+                                                   
+!!! error TS1005: ']' expected.
+!!! related TS1007 tests/cases/compiler/missingCloseBracketInArray.ts:1:32: The parser expected to find a ']' to match the '[' token here.
\ No newline at end of file
diff --git a/tests/baselines/reference/missingCloseBracketInArray.js b/tests/baselines/reference/missingCloseBracketInArray.js
new file mode 100644
index 00000000000..cb842d1cc74
--- /dev/null
+++ b/tests/baselines/reference/missingCloseBracketInArray.js
@@ -0,0 +1,5 @@
+//// [missingCloseBracketInArray.ts]
+var alphas:string[] = alphas = ["1","2","3","4"
+
+//// [missingCloseBracketInArray.js]
+var alphas = alphas = ["1", "2", "3", "4"];
diff --git a/tests/baselines/reference/missingCloseBracketInArray.symbols b/tests/baselines/reference/missingCloseBracketInArray.symbols
new file mode 100644
index 00000000000..4d28f8945fd
--- /dev/null
+++ b/tests/baselines/reference/missingCloseBracketInArray.symbols
@@ -0,0 +1,5 @@
+=== tests/cases/compiler/missingCloseBracketInArray.ts ===
+var alphas:string[] = alphas = ["1","2","3","4"
+>alphas : Symbol(alphas, Decl(missingCloseBracketInArray.ts, 0, 3))
+>alphas : Symbol(alphas, Decl(missingCloseBracketInArray.ts, 0, 3))
+
diff --git a/tests/baselines/reference/missingCloseBracketInArray.types b/tests/baselines/reference/missingCloseBracketInArray.types
new file mode 100644
index 00000000000..557a865827c
--- /dev/null
+++ b/tests/baselines/reference/missingCloseBracketInArray.types
@@ -0,0 +1,11 @@
+=== tests/cases/compiler/missingCloseBracketInArray.ts ===
+var alphas:string[] = alphas = ["1","2","3","4"
+>alphas : string[]
+>alphas = ["1","2","3","4" : string[]
+>alphas : string[]
+>["1","2","3","4" : string[]
+>"1" : "1"
+>"2" : "2"
+>"3" : "3"
+>"4" : "4"
+
diff --git a/tests/baselines/reference/missingCloseParenStatements.errors.txt b/tests/baselines/reference/missingCloseParenStatements.errors.txt
new file mode 100644
index 00000000000..3f49d5a0366
--- /dev/null
+++ b/tests/baselines/reference/missingCloseParenStatements.errors.txt
@@ -0,0 +1,32 @@
+tests/cases/compiler/missingCloseParenStatements.ts(2,26): error TS1005: ')' expected.
+tests/cases/compiler/missingCloseParenStatements.ts(4,5): error TS1005: ')' expected.
+tests/cases/compiler/missingCloseParenStatements.ts(8,39): error TS1005: ')' expected.
+tests/cases/compiler/missingCloseParenStatements.ts(11,35): error TS1005: ')' expected.
+
+
+==== tests/cases/compiler/missingCloseParenStatements.ts (4 errors) ====
+    var a1, a2, a3 = 0;
+    if ( a1 && (a2 + a3 > 0) {
+                             ~
+!!! error TS1005: ')' expected.
+!!! related TS1007 tests/cases/compiler/missingCloseParenStatements.ts:2:4: The parser expected to find a ')' to match the '(' token here.
+        while( (a2 > 0) && a1
+        {
+        ~
+!!! error TS1005: ')' expected.
+!!! related TS1007 tests/cases/compiler/missingCloseParenStatements.ts:3:10: The parser expected to find a ')' to match the '(' token here.
+            do {
+                var i = i + 1;
+                a1 = a1 + i;
+                with ((a2 + a3 > 0) && a1 {
+                                          ~
+!!! error TS1005: ')' expected.
+!!! related TS1007 tests/cases/compiler/missingCloseParenStatements.ts:8:18: The parser expected to find a ')' to match the '(' token here.
+                    console.log(x);
+                  }
+            } while (i < 5 && (a1 > 5);
+                                      ~
+!!! error TS1005: ')' expected.
+!!! related TS1007 tests/cases/compiler/missingCloseParenStatements.ts:11:17: The parser expected to find a ')' to match the '(' token here.
+        }
+    }
\ No newline at end of file
diff --git a/tests/baselines/reference/missingCloseParenStatements.js b/tests/baselines/reference/missingCloseParenStatements.js
new file mode 100644
index 00000000000..8ba56b6b881
--- /dev/null
+++ b/tests/baselines/reference/missingCloseParenStatements.js
@@ -0,0 +1,28 @@
+//// [missingCloseParenStatements.ts]
+var a1, a2, a3 = 0;
+if ( a1 && (a2 + a3 > 0) {
+    while( (a2 > 0) && a1
+    {
+        do {
+            var i = i + 1;
+            a1 = a1 + i;
+            with ((a2 + a3 > 0) && a1 {
+                console.log(x);
+              }
+        } while (i < 5 && (a1 > 5);
+    }
+}
+
+//// [missingCloseParenStatements.js]
+var a1, a2, a3 = 0;
+if (a1 && (a2 + a3 > 0)) {
+    while ((a2 > 0) && a1) {
+        do {
+            var i = i + 1;
+            a1 = a1 + i;
+            with ((a2 + a3 > 0) && a1) {
+                console.log(x);
+            }
+        } while (i < 5 && (a1 > 5));
+    }
+}
diff --git a/tests/baselines/reference/missingCloseParenStatements.symbols b/tests/baselines/reference/missingCloseParenStatements.symbols
new file mode 100644
index 00000000000..e403570f8e8
--- /dev/null
+++ b/tests/baselines/reference/missingCloseParenStatements.symbols
@@ -0,0 +1,37 @@
+=== tests/cases/compiler/missingCloseParenStatements.ts ===
+var a1, a2, a3 = 0;
+>a1 : Symbol(a1, Decl(missingCloseParenStatements.ts, 0, 3))
+>a2 : Symbol(a2, Decl(missingCloseParenStatements.ts, 0, 7))
+>a3 : Symbol(a3, Decl(missingCloseParenStatements.ts, 0, 11))
+
+if ( a1 && (a2 + a3 > 0) {
+>a1 : Symbol(a1, Decl(missingCloseParenStatements.ts, 0, 3))
+>a2 : Symbol(a2, Decl(missingCloseParenStatements.ts, 0, 7))
+>a3 : Symbol(a3, Decl(missingCloseParenStatements.ts, 0, 11))
+
+    while( (a2 > 0) && a1
+>a2 : Symbol(a2, Decl(missingCloseParenStatements.ts, 0, 7))
+>a1 : Symbol(a1, Decl(missingCloseParenStatements.ts, 0, 3))
+    {
+        do {
+            var i = i + 1;
+>i : Symbol(i, Decl(missingCloseParenStatements.ts, 5, 15))
+>i : Symbol(i, Decl(missingCloseParenStatements.ts, 5, 15))
+
+            a1 = a1 + i;
+>a1 : Symbol(a1, Decl(missingCloseParenStatements.ts, 0, 3))
+>a1 : Symbol(a1, Decl(missingCloseParenStatements.ts, 0, 3))
+>i : Symbol(i, Decl(missingCloseParenStatements.ts, 5, 15))
+
+            with ((a2 + a3 > 0) && a1 {
+>a2 : Symbol(a2, Decl(missingCloseParenStatements.ts, 0, 7))
+>a3 : Symbol(a3, Decl(missingCloseParenStatements.ts, 0, 11))
+>a1 : Symbol(a1, Decl(missingCloseParenStatements.ts, 0, 3))
+
+                console.log(x);
+              }
+        } while (i < 5 && (a1 > 5);
+>i : Symbol(i, Decl(missingCloseParenStatements.ts, 5, 15))
+>a1 : Symbol(a1, Decl(missingCloseParenStatements.ts, 0, 3))
+    }
+}
diff --git a/tests/baselines/reference/missingCloseParenStatements.types b/tests/baselines/reference/missingCloseParenStatements.types
new file mode 100644
index 00000000000..0d1b7469f60
--- /dev/null
+++ b/tests/baselines/reference/missingCloseParenStatements.types
@@ -0,0 +1,67 @@
+=== tests/cases/compiler/missingCloseParenStatements.ts ===
+var a1, a2, a3 = 0;
+>a1 : any
+>a2 : any
+>a3 : number
+>0 : 0
+
+if ( a1 && (a2 + a3 > 0) {
+>a1 && (a2 + a3 > 0) : boolean
+>a1 : any
+>(a2 + a3 > 0) : boolean
+>a2 + a3 > 0 : boolean
+>a2 + a3 : any
+>a2 : any
+>a3 : number
+>0 : 0
+
+    while( (a2 > 0) && a1
+>(a2 > 0) && a1 : any
+>(a2 > 0) : boolean
+>a2 > 0 : boolean
+>a2 : any
+>0 : 0
+>a1 : any
+    {
+        do {
+            var i = i + 1;
+>i : any
+>i + 1 : any
+>i : any
+>1 : 1
+
+            a1 = a1 + i;
+>a1 = a1 + i : any
+>a1 : any
+>a1 + i : any
+>a1 : any
+>i : any
+
+            with ((a2 + a3 > 0) && a1 {
+>(a2 + a3 > 0) && a1 : any
+>(a2 + a3 > 0) : boolean
+>a2 + a3 > 0 : boolean
+>a2 + a3 : any
+>a2 : any
+>a3 : number
+>0 : 0
+>a1 : any
+
+                console.log(x);
+>console.log(x) : any
+>console.log : any
+>console : any
+>log : any
+>x : any
+              }
+        } while (i < 5 && (a1 > 5);
+>i < 5 && (a1 > 5) : boolean
+>i < 5 : boolean
+>i : any
+>5 : 5
+>(a1 > 5) : boolean
+>a1 > 5 : boolean
+>a1 : any
+>5 : 5
+    }
+}
diff --git a/tests/baselines/reference/nestedClassDeclaration.errors.txt b/tests/baselines/reference/nestedClassDeclaration.errors.txt
index 5540ee02437..f897c38d681 100644
--- a/tests/baselines/reference/nestedClassDeclaration.errors.txt
+++ b/tests/baselines/reference/nestedClassDeclaration.errors.txt
@@ -32,7 +32,6 @@ tests/cases/conformance/classes/nestedClassDeclaration.ts(17,1): error TS1128: D
 !!! error TS2304: Cannot find name 'C4'.
                  ~
 !!! error TS1005: ',' expected.
-!!! related TS1007 tests/cases/conformance/classes/nestedClassDeclaration.ts:14:9: The parser expected to find a '}' to match the '{' token here.
         }
     }
     ~
diff --git a/tests/baselines/reference/objectLiteralWithSemicolons4.errors.txt b/tests/baselines/reference/objectLiteralWithSemicolons4.errors.txt
index 651c0b66df7..544bddafff2 100644
--- a/tests/baselines/reference/objectLiteralWithSemicolons4.errors.txt
+++ b/tests/baselines/reference/objectLiteralWithSemicolons4.errors.txt
@@ -9,5 +9,4 @@ tests/cases/compiler/objectLiteralWithSemicolons4.ts(3,1): error TS1005: ',' exp
 !!! error TS18004: No value exists in scope for the shorthand property 'a'. Either declare one or provide an initializer.
     ;
     ~
-!!! error TS1005: ',' expected.
-!!! related TS1007 tests/cases/compiler/objectLiteralWithSemicolons4.ts:1:9: The parser expected to find a '}' to match the '{' token here.
\ No newline at end of file
+!!! error TS1005: ',' expected.
\ No newline at end of file
diff --git a/tests/baselines/reference/objectSpreadNegativeParse.errors.txt b/tests/baselines/reference/objectSpreadNegativeParse.errors.txt
index 692fb7617da..b37200c4f02 100644
--- a/tests/baselines/reference/objectSpreadNegativeParse.errors.txt
+++ b/tests/baselines/reference/objectSpreadNegativeParse.errors.txt
@@ -28,7 +28,6 @@ tests/cases/conformance/types/spread/objectSpreadNegativeParse.ts(4,20): error T
 !!! error TS2304: Cannot find name 'matchMedia'.
                                ~
 !!! error TS1005: ',' expected.
-!!! related TS1007 tests/cases/conformance/types/spread/objectSpreadNegativeParse.ts:3:10: The parser expected to find a '}' to match the '{' token here.
                                   ~
 !!! error TS1128: Declaration or statement expected.
     let o10 = { ...get x() { return 12; }};
diff --git a/tests/baselines/reference/parseErrorIncorrectReturnToken.errors.txt b/tests/baselines/reference/parseErrorIncorrectReturnToken.errors.txt
index bc43cd5b776..2cf728848e4 100644
--- a/tests/baselines/reference/parseErrorIncorrectReturnToken.errors.txt
+++ b/tests/baselines/reference/parseErrorIncorrectReturnToken.errors.txt
@@ -25,7 +25,6 @@ tests/cases/compiler/parseErrorIncorrectReturnToken.ts(12,1): error TS1128: Decl
         m(n: number) => string {
                      ~~
 !!! error TS1005: '{' expected.
-!!! related TS1007 tests/cases/compiler/parseErrorIncorrectReturnToken.ts:8:9: The parser expected to find a '}' to match the '{' token here.
                         ~~~~~~
 !!! error TS2693: 'string' only refers to a type, but is being used as a value here.
                                ~
diff --git a/tests/baselines/reference/parserErrorRecoveryIfStatement2.errors.txt b/tests/baselines/reference/parserErrorRecoveryIfStatement2.errors.txt
index 45dd9935a62..b88c48182a2 100644
--- a/tests/baselines/reference/parserErrorRecoveryIfStatement2.errors.txt
+++ b/tests/baselines/reference/parserErrorRecoveryIfStatement2.errors.txt
@@ -11,6 +11,7 @@ tests/cases/conformance/parser/ecmascript5/ErrorRecovery/IfStatements/parserErro
       }
       ~
 !!! error TS1005: ')' expected.
+!!! related TS1007 tests/cases/conformance/parser/ecmascript5/ErrorRecovery/IfStatements/parserErrorRecoveryIfStatement2.ts:3:8: The parser expected to find a ')' to match the '(' token here.
       f2() {
       }
       f3() {
diff --git a/tests/baselines/reference/parserErrorRecoveryIfStatement3.errors.txt b/tests/baselines/reference/parserErrorRecoveryIfStatement3.errors.txt
index 631cdb08a90..cfd645e5925 100644
--- a/tests/baselines/reference/parserErrorRecoveryIfStatement3.errors.txt
+++ b/tests/baselines/reference/parserErrorRecoveryIfStatement3.errors.txt
@@ -11,6 +11,7 @@ tests/cases/conformance/parser/ecmascript5/ErrorRecovery/IfStatements/parserErro
       }
       ~
 !!! error TS1005: ')' expected.
+!!! related TS1007 tests/cases/conformance/parser/ecmascript5/ErrorRecovery/IfStatements/parserErrorRecoveryIfStatement3.ts:3:8: The parser expected to find a ')' to match the '(' token here.
       f2() {
       }
       f3() {
diff --git a/tests/baselines/reference/parserFuzz1.errors.txt b/tests/baselines/reference/parserFuzz1.errors.txt
index e11d25c48fa..e90dda55244 100644
--- a/tests/baselines/reference/parserFuzz1.errors.txt
+++ b/tests/baselines/reference/parserFuzz1.errors.txt
@@ -20,5 +20,4 @@ tests/cases/conformance/parser/ecmascript5/ErrorRecovery/parserFuzz1.ts(2,15): e
         ~~~~~~
 !!! error TS1005: ';' expected.
                   
-!!! error TS1005: '{' expected.
-!!! related TS1007 tests/cases/conformance/parser/ecmascript5/ErrorRecovery/parserFuzz1.ts:1:9: The parser expected to find a '}' to match the '{' token here.
\ No newline at end of file
+!!! error TS1005: '{' expected.
\ No newline at end of file
diff --git a/tests/baselines/reference/redeclaredProperty.errors.txt b/tests/baselines/reference/redeclaredProperty.errors.txt
new file mode 100644
index 00000000000..331e5610f8d
--- /dev/null
+++ b/tests/baselines/reference/redeclaredProperty.errors.txt
@@ -0,0 +1,21 @@
+tests/cases/conformance/classes/propertyMemberDeclarations/redeclaredProperty.ts(7,12): error TS2729: Property 'b' is used before its initialization.
+
+
+==== tests/cases/conformance/classes/propertyMemberDeclarations/redeclaredProperty.ts (1 errors) ====
+    class Base {
+      b = 1;
+    }
+    
+    class Derived extends Base {
+      b;
+      d = this.b;
+               ~
+!!! error TS2729: Property 'b' is used before its initialization.
+!!! related TS2728 tests/cases/conformance/classes/propertyMemberDeclarations/redeclaredProperty.ts:6:3: 'b' is declared here.
+    
+      constructor() {
+        super();
+        this.b = 2;
+      }
+    }
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/redeclaredProperty.js b/tests/baselines/reference/redeclaredProperty.js
new file mode 100644
index 00000000000..20af007d62e
--- /dev/null
+++ b/tests/baselines/reference/redeclaredProperty.js
@@ -0,0 +1,28 @@
+//// [redeclaredProperty.ts]
+class Base {
+  b = 1;
+}
+
+class Derived extends Base {
+  b;
+  d = this.b;
+
+  constructor() {
+    super();
+    this.b = 2;
+  }
+}
+
+
+//// [redeclaredProperty.js]
+class Base {
+    b = 1;
+}
+class Derived extends Base {
+    b;
+    d = this.b;
+    constructor() {
+        super();
+        this.b = 2;
+    }
+}
diff --git a/tests/baselines/reference/redefinedPararameterProperty.errors.txt b/tests/baselines/reference/redefinedPararameterProperty.errors.txt
new file mode 100644
index 00000000000..65763261152
--- /dev/null
+++ b/tests/baselines/reference/redefinedPararameterProperty.errors.txt
@@ -0,0 +1,19 @@
+tests/cases/conformance/classes/propertyMemberDeclarations/redefinedPararameterProperty.ts(6,14): error TS2729: Property 'a' is used before its initialization.
+
+
+==== tests/cases/conformance/classes/propertyMemberDeclarations/redefinedPararameterProperty.ts (1 errors) ====
+    class Base {
+        a = 1;
+      }
+      
+      class Derived extends Base {
+        b = this.a /*undefined*/;
+                 ~
+!!! error TS2729: Property 'a' is used before its initialization.
+!!! related TS2728 tests/cases/conformance/classes/propertyMemberDeclarations/redefinedPararameterProperty.ts:8:17: 'a' is declared here.
+      
+        constructor(public a: number) {
+            super();
+        }
+      }
+      
\ No newline at end of file
diff --git a/tests/baselines/reference/redefinedPararameterProperty.js b/tests/baselines/reference/redefinedPararameterProperty.js
new file mode 100644
index 00000000000..8ad9b5facc0
--- /dev/null
+++ b/tests/baselines/reference/redefinedPararameterProperty.js
@@ -0,0 +1,26 @@
+//// [redefinedPararameterProperty.ts]
+class Base {
+    a = 1;
+  }
+  
+  class Derived extends Base {
+    b = this.a /*undefined*/;
+  
+    constructor(public a: number) {
+        super();
+    }
+  }
+  
+
+//// [redefinedPararameterProperty.js]
+class Base {
+    a = 1;
+}
+class Derived extends Base {
+    a;
+    b = this.a /*undefined*/;
+    constructor(a) {
+        super();
+        this.a = a;
+    }
+}
diff --git a/tests/baselines/reference/redefinedPararameterProperty.symbols b/tests/baselines/reference/redefinedPararameterProperty.symbols
new file mode 100644
index 00000000000..5e05041f539
--- /dev/null
+++ b/tests/baselines/reference/redefinedPararameterProperty.symbols
@@ -0,0 +1,3 @@
+=== tests/cases/conformance/classes/propertyMemberDeclarations/redefinedPararameterProperty.ts ===
+
+No type information for this code.
\ No newline at end of file
diff --git a/tests/baselines/reference/redefinedPararameterProperty.types b/tests/baselines/reference/redefinedPararameterProperty.types
new file mode 100644
index 00000000000..5e05041f539
--- /dev/null
+++ b/tests/baselines/reference/redefinedPararameterProperty.types
@@ -0,0 +1,3 @@
+=== tests/cases/conformance/classes/propertyMemberDeclarations/redefinedPararameterProperty.ts ===
+
+No type information for this code.
\ No newline at end of file
diff --git a/tests/baselines/reference/reservedWords2.errors.txt b/tests/baselines/reference/reservedWords2.errors.txt
index 599010b4368..6ecb9471631 100644
--- a/tests/baselines/reference/reservedWords2.errors.txt
+++ b/tests/baselines/reference/reservedWords2.errors.txt
@@ -45,6 +45,7 @@ tests/cases/compiler/reservedWords2.ts(12,17): error TS1138: Parameter declarati
 !!! error TS2580: Cannot find name 'require'. Do you need to install type definitions for node? Try `npm i --save-dev @types/node`.
                                   ~
 !!! error TS1005: ')' expected.
+!!! related TS1007 tests/cases/compiler/reservedWords2.ts:1:14: The parser expected to find a ')' to match the '(' token here.
     import * as  while from "foo"
                
 !!! error TS2300: Duplicate identifier '(Missing)'.
@@ -58,6 +59,7 @@ tests/cases/compiler/reservedWords2.ts(12,17): error TS1138: Parameter declarati
 !!! error TS2304: Cannot find name 'from'.
                             ~~~~~
 !!! error TS1005: ')' expected.
+!!! related TS1007 tests/cases/compiler/reservedWords2.ts:2:20: The parser expected to find a ')' to match the '(' token here.
     
     var typeof = 10;
         ~~~~~~
diff --git a/tests/baselines/reference/templateLiteralTypes2.errors.txt b/tests/baselines/reference/templateLiteralTypes2.errors.txt
index 662b6704d63..7e9308d47e6 100644
--- a/tests/baselines/reference/templateLiteralTypes2.errors.txt
+++ b/tests/baselines/reference/templateLiteralTypes2.errors.txt
@@ -1,13 +1,9 @@
 tests/cases/conformance/types/literal/templateLiteralTypes2.ts(23,11): error TS2322: Type 'string' is not assignable to type '`abc${string}`'.
 tests/cases/conformance/types/literal/templateLiteralTypes2.ts(29,11): error TS2322: Type 'string' is not assignable to type '`foo${string}` | `bar${string}`'.
 tests/cases/conformance/types/literal/templateLiteralTypes2.ts(32,11): error TS2322: Type 'string' is not assignable to type '`foo${string}` | `bar${string}` | `baz${string}`'.
-tests/cases/conformance/types/literal/templateLiteralTypes2.ts(67,9): error TS2322: Type '`foo${number}`' is not assignable to type 'String'.
-tests/cases/conformance/types/literal/templateLiteralTypes2.ts(68,9): error TS2322: Type '`foo${number}`' is not assignable to type 'Object'.
-tests/cases/conformance/types/literal/templateLiteralTypes2.ts(69,9): error TS2322: Type '`foo${number}`' is not assignable to type '{}'.
-tests/cases/conformance/types/literal/templateLiteralTypes2.ts(70,9): error TS2322: Type '`foo${number}`' is not assignable to type '{ length: number; }'.
 
 
-==== tests/cases/conformance/types/literal/templateLiteralTypes2.ts (7 errors) ====
+==== tests/cases/conformance/types/literal/templateLiteralTypes2.ts (3 errors) ====
     function ft1<T extends string>(s: string, n: number, u: 'foo' | 'bar' | 'baz', t: T) {
         const c1 = `abc${s}`;  // `abc${string}`
         const c2 = `abc${n}`;  // `abc${number}`
@@ -81,17 +77,9 @@ tests/cases/conformance/types/literal/templateLiteralTypes2.ts(70,9): error TS23
     function ft14(t: `foo${number}`) {
         let x1: string = t;
         let x2: String = t;
-            ~~
-!!! error TS2322: Type '`foo${number}`' is not assignable to type 'String'.
         let x3: Object = t;
-            ~~
-!!! error TS2322: Type '`foo${number}`' is not assignable to type 'Object'.
         let x4: {} = t;
-            ~~
-!!! error TS2322: Type '`foo${number}`' is not assignable to type '{}'.
         let x6: { length: number } = t;
-            ~~
-!!! error TS2322: Type '`foo${number}`' is not assignable to type '{ length: number; }'.
     }
     
     declare function g1<T>(x: T): T;
@@ -134,4 +122,10 @@ tests/cases/conformance/types/literal/templateLiteralTypes2.ts(70,9): error TS23
     function getCardTitle(title: string): `test-${string}` {
         return `test-${title}`;
     }
+    
+    // Repro from #43424
+    
+    const interpolatedStyle = { rotate: 12 };
+    function C2(transform: "-moz-initial" | (string & {})) { return 12; }
+    C2(`rotate(${interpolatedStyle.rotate}dig)`);
     
\ No newline at end of file
diff --git a/tests/baselines/reference/templateLiteralTypes2.js b/tests/baselines/reference/templateLiteralTypes2.js
index 87be2dbe4fa..37c101be269 100644
--- a/tests/baselines/reference/templateLiteralTypes2.js
+++ b/tests/baselines/reference/templateLiteralTypes2.js
@@ -111,6 +111,12 @@ const pixelStringWithTemplate: PixelValueType = `${pixelValue}px`;
 function getCardTitle(title: string): `test-${string}` {
     return `test-${title}`;
 }
+
+// Repro from #43424
+
+const interpolatedStyle = { rotate: 12 };
+function C2(transform: "-moz-initial" | (string & {})) { return 12; }
+C2(`rotate(${interpolatedStyle.rotate}dig)`);
 
 
 //// [templateLiteralTypes2.js]
@@ -194,6 +200,10 @@ var pixelStringWithTemplate = pixelValue + "px";
 function getCardTitle(title) {
     return "test-" + title;
 }
+// Repro from #43424
+var interpolatedStyle = { rotate: 12 };
+function C2(transform) { return 12; }
+C2("rotate(" + interpolatedStyle.rotate + "dig)");
 
 
 //// [templateLiteralTypes2.d.ts]
@@ -225,3 +235,7 @@ declare type PixelValueType = `${number}px`;
 declare const pixelString: PixelValueType;
 declare const pixelStringWithTemplate: PixelValueType;
 declare function getCardTitle(title: string): `test-${string}`;
+declare const interpolatedStyle: {
+    rotate: number;
+};
+declare function C2(transform: "-moz-initial" | (string & {})): number;
diff --git a/tests/baselines/reference/templateLiteralTypes2.symbols b/tests/baselines/reference/templateLiteralTypes2.symbols
index 6348ebce7f9..4ac9d428a06 100644
--- a/tests/baselines/reference/templateLiteralTypes2.symbols
+++ b/tests/baselines/reference/templateLiteralTypes2.symbols
@@ -361,3 +361,19 @@ function getCardTitle(title: string): `test-${string}` {
 >title : Symbol(title, Decl(templateLiteralTypes2.ts, 109, 22))
 }
 
+// Repro from #43424
+
+const interpolatedStyle = { rotate: 12 };
+>interpolatedStyle : Symbol(interpolatedStyle, Decl(templateLiteralTypes2.ts, 115, 5))
+>rotate : Symbol(rotate, Decl(templateLiteralTypes2.ts, 115, 27))
+
+function C2(transform: "-moz-initial" | (string & {})) { return 12; }
+>C2 : Symbol(C2, Decl(templateLiteralTypes2.ts, 115, 41))
+>transform : Symbol(transform, Decl(templateLiteralTypes2.ts, 116, 12))
+
+C2(`rotate(${interpolatedStyle.rotate}dig)`);
+>C2 : Symbol(C2, Decl(templateLiteralTypes2.ts, 115, 41))
+>interpolatedStyle.rotate : Symbol(rotate, Decl(templateLiteralTypes2.ts, 115, 27))
+>interpolatedStyle : Symbol(interpolatedStyle, Decl(templateLiteralTypes2.ts, 115, 5))
+>rotate : Symbol(rotate, Decl(templateLiteralTypes2.ts, 115, 27))
+
diff --git a/tests/baselines/reference/templateLiteralTypes2.types b/tests/baselines/reference/templateLiteralTypes2.types
index 274e3eb4f0b..24096c9d782 100644
--- a/tests/baselines/reference/templateLiteralTypes2.types
+++ b/tests/baselines/reference/templateLiteralTypes2.types
@@ -392,3 +392,24 @@ function getCardTitle(title: string): `test-${string}` {
 >title : string
 }
 
+// Repro from #43424
+
+const interpolatedStyle = { rotate: 12 };
+>interpolatedStyle : { rotate: number; }
+>{ rotate: 12 } : { rotate: number; }
+>rotate : number
+>12 : 12
+
+function C2(transform: "-moz-initial" | (string & {})) { return 12; }
+>C2 : (transform: "-moz-initial" | (string & {})) => number
+>transform : (string & {}) | "-moz-initial"
+>12 : 12
+
+C2(`rotate(${interpolatedStyle.rotate}dig)`);
+>C2(`rotate(${interpolatedStyle.rotate}dig)`) : number
+>C2 : (transform: (string & {}) | "-moz-initial") => number
+>`rotate(${interpolatedStyle.rotate}dig)` : `rotate(${number}dig)`
+>interpolatedStyle.rotate : number
+>interpolatedStyle : { rotate: number; }
+>rotate : number
+
diff --git a/tests/baselines/reference/truthinessCallExpressionCoercion.errors.txt b/tests/baselines/reference/truthinessCallExpressionCoercion.errors.txt
index 0e0b2c98404..132738e4ac1 100644
--- a/tests/baselines/reference/truthinessCallExpressionCoercion.errors.txt
+++ b/tests/baselines/reference/truthinessCallExpressionCoercion.errors.txt
@@ -1,17 +1,17 @@
-tests/cases/compiler/truthinessCallExpressionCoercion.ts(2,9): error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
-tests/cases/compiler/truthinessCallExpressionCoercion.ts(18,9): error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
-tests/cases/compiler/truthinessCallExpressionCoercion.ts(36,9): error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
-tests/cases/compiler/truthinessCallExpressionCoercion.ts(50,9): error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
-tests/cases/compiler/truthinessCallExpressionCoercion.ts(66,13): error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
-tests/cases/compiler/truthinessCallExpressionCoercion.ts(76,9): error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
-tests/cases/compiler/truthinessCallExpressionCoercion.ts(82,9): error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
+tests/cases/compiler/truthinessCallExpressionCoercion.ts(2,9): error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
+tests/cases/compiler/truthinessCallExpressionCoercion.ts(18,9): error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
+tests/cases/compiler/truthinessCallExpressionCoercion.ts(36,9): error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
+tests/cases/compiler/truthinessCallExpressionCoercion.ts(50,9): error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
+tests/cases/compiler/truthinessCallExpressionCoercion.ts(66,13): error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
+tests/cases/compiler/truthinessCallExpressionCoercion.ts(76,9): error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
+tests/cases/compiler/truthinessCallExpressionCoercion.ts(82,9): error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
 
 
 ==== tests/cases/compiler/truthinessCallExpressionCoercion.ts (7 errors) ====
     function onlyErrorsWhenTestingNonNullableFunctionType(required: () => boolean, optional?: () => boolean) {
         if (required) { // error
             ~~~~~~~~
-!!! error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
+!!! error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
         }
     
         if (optional) { // ok
@@ -29,7 +29,7 @@ tests/cases/compiler/truthinessCallExpressionCoercion.ts(82,9): error TS2774: Th
     
         if (test) { // error
             ~~~~
-!!! error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
+!!! error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
             console.log('test');
         }
         
@@ -49,7 +49,7 @@ tests/cases/compiler/truthinessCallExpressionCoercion.ts(82,9): error TS2774: Th
         
         if (test) { // error
             ~~~~
-!!! error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
+!!! error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
             [() => null].forEach(test => {
                 test();
             });
@@ -65,7 +65,7 @@ tests/cases/compiler/truthinessCallExpressionCoercion.ts(82,9): error TS2774: Th
     
         if (x.foo.bar) { // error
             ~~~~~~~~~
-!!! error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
+!!! error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
         }
     
         if (x.foo.bar) { // ok
@@ -83,7 +83,7 @@ tests/cases/compiler/truthinessCallExpressionCoercion.ts(82,9): error TS2774: Th
         test() {
             if (this.isUser) { // error
                 ~~~~~~~~~~~
-!!! error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
+!!! error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
             }
     
             if (this.maybeIsUser) { // ok
@@ -95,7 +95,7 @@ tests/cases/compiler/truthinessCallExpressionCoercion.ts(82,9): error TS2774: Th
     function A(stats: StatsBase<any>) {
         if (stats.isDirectory) { // err
             ~~~~~~~~~~~~~~~~~
-!!! error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
+!!! error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
             console.log(`[Directory] ${stats.ctime}`)
         }
     }
@@ -103,7 +103,7 @@ tests/cases/compiler/truthinessCallExpressionCoercion.ts(82,9): error TS2774: Th
     function B(a: Nested, b: Nested) {
         if (a.stats.isDirectory) { // err
             ~~~~~~~~~~~~~~~~~~~
-!!! error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
+!!! error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
             b.stats.isDirectory(); 
         }
         if (a.stats.isDirectory) { // ok
diff --git a/tests/baselines/reference/truthinessCallExpressionCoercion1.errors.txt b/tests/baselines/reference/truthinessCallExpressionCoercion1.errors.txt
index ed7ba0a5709..4c041935cde 100644
--- a/tests/baselines/reference/truthinessCallExpressionCoercion1.errors.txt
+++ b/tests/baselines/reference/truthinessCallExpressionCoercion1.errors.txt
@@ -1,8 +1,8 @@
-tests/cases/compiler/truthinessCallExpressionCoercion1.ts(3,5): error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
-tests/cases/compiler/truthinessCallExpressionCoercion1.ts(19,5): error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
-tests/cases/compiler/truthinessCallExpressionCoercion1.ts(33,5): error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
-tests/cases/compiler/truthinessCallExpressionCoercion1.ts(46,5): error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
-tests/cases/compiler/truthinessCallExpressionCoercion1.ts(76,9): error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
+tests/cases/compiler/truthinessCallExpressionCoercion1.ts(3,5): error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
+tests/cases/compiler/truthinessCallExpressionCoercion1.ts(19,5): error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
+tests/cases/compiler/truthinessCallExpressionCoercion1.ts(33,5): error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
+tests/cases/compiler/truthinessCallExpressionCoercion1.ts(46,5): error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
+tests/cases/compiler/truthinessCallExpressionCoercion1.ts(76,9): error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
 
 
 ==== tests/cases/compiler/truthinessCallExpressionCoercion1.ts (5 errors) ====
@@ -10,7 +10,7 @@ tests/cases/compiler/truthinessCallExpressionCoercion1.ts(76,9): error TS2774: T
         // error
         required ? console.log('required') : undefined;
         ~~~~~~~~
-!!! error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
+!!! error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
     
         // ok
         optional ? console.log('optional') : undefined;
@@ -28,7 +28,7 @@ tests/cases/compiler/truthinessCallExpressionCoercion1.ts(76,9): error TS2774: T
         // error
         test ? console.log('test') : undefined;
         ~~~~
-!!! error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
+!!! error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
     
         // ok
         test ? console.log(test) : undefined;
@@ -44,7 +44,7 @@ tests/cases/compiler/truthinessCallExpressionCoercion1.ts(76,9): error TS2774: T
         // error
         test
         ~~~~
-!!! error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
+!!! error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
             ? [() => null].forEach(test => { test() })
             : undefined;
     }
@@ -59,7 +59,7 @@ tests/cases/compiler/truthinessCallExpressionCoercion1.ts(76,9): error TS2774: T
         // error
         x.foo.bar ? console.log('x.foo.bar') : undefined;
         ~~~~~~~~~
-!!! error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
+!!! error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
     
         // ok
         x.foo.bar ? x.foo.bar : undefined;
@@ -91,7 +91,7 @@ tests/cases/compiler/truthinessCallExpressionCoercion1.ts(76,9): error TS2774: T
             // error
             this.isUser ? console.log('this.isUser') : undefined;
             ~~~~~~~~~~~
-!!! error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
+!!! error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
     
             // ok
             this.maybeIsUser ? console.log('this.maybeIsUser') : undefined;
diff --git a/tests/baselines/reference/truthinessCallExpressionCoercion2.errors.txt b/tests/baselines/reference/truthinessCallExpressionCoercion2.errors.txt
index 6582157de84..d744718a8de 100644
--- a/tests/baselines/reference/truthinessCallExpressionCoercion2.errors.txt
+++ b/tests/baselines/reference/truthinessCallExpressionCoercion2.errors.txt
@@ -1,14 +1,14 @@
-tests/cases/compiler/truthinessCallExpressionCoercion2.ts(11,5): error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
-tests/cases/compiler/truthinessCallExpressionCoercion2.ts(14,10): error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
-tests/cases/compiler/truthinessCallExpressionCoercion2.ts(41,18): error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
-tests/cases/compiler/truthinessCallExpressionCoercion2.ts(44,9): error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
-tests/cases/compiler/truthinessCallExpressionCoercion2.ts(48,11): error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
-tests/cases/compiler/truthinessCallExpressionCoercion2.ts(65,46): error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
-tests/cases/compiler/truthinessCallExpressionCoercion2.ts(76,5): error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
-tests/cases/compiler/truthinessCallExpressionCoercion2.ts(79,10): error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
-tests/cases/compiler/truthinessCallExpressionCoercion2.ts(99,5): error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
-tests/cases/compiler/truthinessCallExpressionCoercion2.ts(109,9): error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
-tests/cases/compiler/truthinessCallExpressionCoercion2.ts(112,14): error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
+tests/cases/compiler/truthinessCallExpressionCoercion2.ts(11,5): error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
+tests/cases/compiler/truthinessCallExpressionCoercion2.ts(14,10): error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
+tests/cases/compiler/truthinessCallExpressionCoercion2.ts(41,18): error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
+tests/cases/compiler/truthinessCallExpressionCoercion2.ts(44,9): error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
+tests/cases/compiler/truthinessCallExpressionCoercion2.ts(48,11): error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
+tests/cases/compiler/truthinessCallExpressionCoercion2.ts(65,46): error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
+tests/cases/compiler/truthinessCallExpressionCoercion2.ts(76,5): error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
+tests/cases/compiler/truthinessCallExpressionCoercion2.ts(79,10): error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
+tests/cases/compiler/truthinessCallExpressionCoercion2.ts(99,5): error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
+tests/cases/compiler/truthinessCallExpressionCoercion2.ts(109,9): error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
+tests/cases/compiler/truthinessCallExpressionCoercion2.ts(112,14): error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
 
 
 ==== tests/cases/compiler/truthinessCallExpressionCoercion2.ts (11 errors) ====
@@ -24,12 +24,12 @@ tests/cases/compiler/truthinessCallExpressionCoercion2.ts(112,14): error TS2774:
         // error
         required1 && console.log('required');
         ~~~~~~~~~
-!!! error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
+!!! error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
     
         // error
         1 && required1 && console.log('required');
              ~~~~~~~~~
-!!! error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
+!!! error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
     
         // ok
         required1 && required1();
@@ -58,18 +58,18 @@ tests/cases/compiler/truthinessCallExpressionCoercion2.ts(112,14): error TS2774:
         // error
         required1 && required2 && required1() && console.log('foo');
                      ~~~~~~~~~
-!!! error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
+!!! error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
     
         // error
         if (required1 && b) {
             ~~~~~~~~~
-!!! error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
+!!! error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
         }
     
         // error
         if (((required1 && b))) {
               ~~~~~~~~~
-!!! error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
+!!! error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
         }
     
         // ok
@@ -88,7 +88,7 @@ tests/cases/compiler/truthinessCallExpressionCoercion2.ts(112,14): error TS2774:
         typeof window !== 'undefined' && window.console &&
             ((window.console as any).firebug || (window.console.exception && window.console.table));
                                                  ~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
+!!! error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
     }
     
     function checksPropertyAccess() {
@@ -101,12 +101,12 @@ tests/cases/compiler/truthinessCallExpressionCoercion2.ts(112,14): error TS2774:
         // error
         x.foo.bar && console.log('x.foo.bar');
         ~~~~~~~~~
-!!! error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
+!!! error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
     
         // error
         1 && x.foo.bar && console.log('x.foo.bar');
              ~~~~~~~~~
-!!! error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
+!!! error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
     
         // ok
         x.foo.bar && x.foo.bar();
@@ -128,7 +128,7 @@ tests/cases/compiler/truthinessCallExpressionCoercion2.ts(112,14): error TS2774:
         // error
         x1.a.b.c && x2.a.b.c();
         ~~~~~~~~
-!!! error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
+!!! error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
     }
     
     class Foo {
@@ -140,12 +140,12 @@ tests/cases/compiler/truthinessCallExpressionCoercion2.ts(112,14): error TS2774:
             // error
             this.required && console.log('required');
             ~~~~~~~~~~~~~
-!!! error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
+!!! error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
     
             // error
             1 && this.required && console.log('required');
                  ~~~~~~~~~~~~~
-!!! error TS2774: This condition will always return true since the function is always defined. Did you mean to call it instead?
+!!! error TS2774: This condition will always return true since this function appears to always be defined. Did you mean to call it instead?
     
             // ok
             this.required && this.required();
diff --git a/tests/baselines/reference/truthinessPromiseCoercion.errors.txt b/tests/baselines/reference/truthinessPromiseCoercion.errors.txt
index a7b7afff1f6..aaba8031475 100644
--- a/tests/baselines/reference/truthinessPromiseCoercion.errors.txt
+++ b/tests/baselines/reference/truthinessPromiseCoercion.errors.txt
@@ -1,5 +1,5 @@
-tests/cases/compiler/truthinessPromiseCoercion.ts(5,9): error TS2367: This condition will always return 'true' since the types 'Promise<number>' and 'false' have no overlap.
-tests/cases/compiler/truthinessPromiseCoercion.ts(9,5): error TS2367: This condition will always return 'true' since the types 'Promise<number>' and 'false' have no overlap.
+tests/cases/compiler/truthinessPromiseCoercion.ts(5,9): error TS2801: This condition will always return true since this 'Promise<number>' appears to always be defined.
+tests/cases/compiler/truthinessPromiseCoercion.ts(9,5): error TS2801: This condition will always return true since this 'Promise<number>' appears to always be defined.
 
 
 ==== tests/cases/compiler/truthinessPromiseCoercion.ts (2 errors) ====
@@ -9,14 +9,14 @@ tests/cases/compiler/truthinessPromiseCoercion.ts(9,5): error TS2367: This condi
     async function f() {
         if (p) {} // err
             ~
-!!! error TS2367: This condition will always return 'true' since the types 'Promise<number>' and 'false' have no overlap.
+!!! error TS2801: This condition will always return true since this 'Promise<number>' appears to always be defined.
 !!! related TS2773 tests/cases/compiler/truthinessPromiseCoercion.ts:5:9: Did you forget to use 'await'?
         if (!!p) {} // no err
         if (p2) {} // no err
     
         p ? f.arguments : f.arguments;
         ~
-!!! error TS2367: This condition will always return 'true' since the types 'Promise<number>' and 'false' have no overlap.
+!!! error TS2801: This condition will always return true since this 'Promise<number>' appears to always be defined.
 !!! related TS2773 tests/cases/compiler/truthinessPromiseCoercion.ts:9:5: Did you forget to use 'await'?
         !!p ? f.arguments : f.arguments;
         p2 ? f.arguments : f.arguments;
diff --git a/tests/baselines/reference/tsbuild/clean/initial-build/file-name-and-output-name-clashing.js b/tests/baselines/reference/tsbuild/clean/initial-build/file-name-and-output-name-clashing.js
new file mode 100644
index 00000000000..e8cecc75d8c
--- /dev/null
+++ b/tests/baselines/reference/tsbuild/clean/initial-build/file-name-and-output-name-clashing.js
@@ -0,0 +1,20 @@
+Input::
+//// [/lib/lib.d.ts]
+
+
+//// [/src/bar.ts]
+
+
+//// [/src/index.js]
+
+
+//// [/src/tsconfig.json]
+{"compilerOptions":{"allowJs":true}}
+
+
+
+Output::
+/lib/tsc --b /src/tsconfig.json -clean
+exitCode:: ExitStatus.Success
+
+
diff --git a/tests/baselines/reference/tsbuild/noEmitOnError/initial-build/syntax-errors-with-incremental.js b/tests/baselines/reference/tsbuild/noEmitOnError/initial-build/syntax-errors-with-incremental.js
index e6fd723a287..43e04e41056 100644
--- a/tests/baselines/reference/tsbuild/noEmitOnError/initial-build/syntax-errors-with-incremental.js
+++ b/tests/baselines/reference/tsbuild/noEmitOnError/initial-build/syntax-errors-with-incremental.js
@@ -47,11 +47,6 @@ Output::
 4 ;
   ~
 
-  src/src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 
 Found 1 error.
 
@@ -81,11 +76,6 @@ Output::
 4 ;
   ~
 
-  src/src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 
 Found 1 error.
 
diff --git a/tests/baselines/reference/tsbuild/noEmitOnError/initial-build/syntax-errors.js b/tests/baselines/reference/tsbuild/noEmitOnError/initial-build/syntax-errors.js
index 4c55b9ce60f..e9ea12ea0d3 100644
--- a/tests/baselines/reference/tsbuild/noEmitOnError/initial-build/syntax-errors.js
+++ b/tests/baselines/reference/tsbuild/noEmitOnError/initial-build/syntax-errors.js
@@ -47,11 +47,6 @@ Output::
 4 ;
   ~
 
-  src/src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 
 Found 1 error.
 
@@ -81,11 +76,6 @@ Output::
 4 ;
   ~
 
-  src/src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 
 Found 1 error.
 
diff --git a/tests/baselines/reference/tsbuild/watchMode/noEmitOnError/does-not-emit-any-files-on-error-with-incremental.js b/tests/baselines/reference/tsbuild/watchMode/noEmitOnError/does-not-emit-any-files-on-error-with-incremental.js
index a05c649643c..8ad612bca9b 100644
--- a/tests/baselines/reference/tsbuild/watchMode/noEmitOnError/does-not-emit-any-files-on-error-with-incremental.js
+++ b/tests/baselines/reference/tsbuild/watchMode/noEmitOnError/does-not-emit-any-files-on-error-with-incremental.js
@@ -56,11 +56,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:35 AM] Found 1 error. Watching for file changes.
 
 
@@ -113,11 +108,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:42 AM] Found 1 error. Watching for file changes.
 
 
diff --git a/tests/baselines/reference/tsbuild/watchMode/noEmitOnError/does-not-emit-any-files-on-error.js b/tests/baselines/reference/tsbuild/watchMode/noEmitOnError/does-not-emit-any-files-on-error.js
index 3e563e8f609..6af8477219c 100644
--- a/tests/baselines/reference/tsbuild/watchMode/noEmitOnError/does-not-emit-any-files-on-error.js
+++ b/tests/baselines/reference/tsbuild/watchMode/noEmitOnError/does-not-emit-any-files-on-error.js
@@ -56,11 +56,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:35 AM] Found 1 error. Watching for file changes.
 
 
@@ -113,11 +108,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:42 AM] Found 1 error. Watching for file changes.
 
 
diff --git a/tests/baselines/reference/tsc/incremental/initial-build/with-noEmitOnError-syntax-errors.js b/tests/baselines/reference/tsc/incremental/initial-build/with-noEmitOnError-syntax-errors.js
index c539e3763b4..61a42c07f86 100644
--- a/tests/baselines/reference/tsc/incremental/initial-build/with-noEmitOnError-syntax-errors.js
+++ b/tests/baselines/reference/tsc/incremental/initial-build/with-noEmitOnError-syntax-errors.js
@@ -47,11 +47,6 @@ Output::
 4 ;
   ~
 
-  src/src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 
 Found 1 error.
 
@@ -166,11 +161,6 @@ Output::
 4 ;
   ~
 
-  src/src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 
 Found 1 error.
 
diff --git a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/assumeChangesOnlyAffectDirectDependencies/with-noEmitOnError-with-incremental.js b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/assumeChangesOnlyAffectDirectDependencies/with-noEmitOnError-with-incremental.js
index 682a68af31e..97c07812515 100644
--- a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/assumeChangesOnlyAffectDirectDependencies/with-noEmitOnError-with-incremental.js
+++ b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/assumeChangesOnlyAffectDirectDependencies/with-noEmitOnError-with-incremental.js
@@ -43,11 +43,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:37 AM] Found 1 error. Watching for file changes.
 
 
@@ -186,11 +181,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:44 AM] Found 1 error. Watching for file changes.
 
 
diff --git a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/assumeChangesOnlyAffectDirectDependencies/with-noEmitOnError.js b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/assumeChangesOnlyAffectDirectDependencies/with-noEmitOnError.js
index 17c877f6ac1..16681988e8f 100644
--- a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/assumeChangesOnlyAffectDirectDependencies/with-noEmitOnError.js
+++ b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/assumeChangesOnlyAffectDirectDependencies/with-noEmitOnError.js
@@ -43,11 +43,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:32 AM] Found 1 error. Watching for file changes.
 
 
@@ -104,11 +99,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:37 AM] Found 1 error. Watching for file changes.
 
 
diff --git a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/assumeChangesOnlyAffectDirectDependenciesAndD/with-noEmitOnError-with-incremental.js b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/assumeChangesOnlyAffectDirectDependenciesAndD/with-noEmitOnError-with-incremental.js
index 0e63864873c..9b41d9d0913 100644
--- a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/assumeChangesOnlyAffectDirectDependenciesAndD/with-noEmitOnError-with-incremental.js
+++ b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/assumeChangesOnlyAffectDirectDependenciesAndD/with-noEmitOnError-with-incremental.js
@@ -43,11 +43,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:37 AM] Found 1 error. Watching for file changes.
 
 
@@ -187,11 +182,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:44 AM] Found 1 error. Watching for file changes.
 
 
diff --git a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/assumeChangesOnlyAffectDirectDependenciesAndD/with-noEmitOnError.js b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/assumeChangesOnlyAffectDirectDependenciesAndD/with-noEmitOnError.js
index 9c9b6f756c1..bae815eebeb 100644
--- a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/assumeChangesOnlyAffectDirectDependenciesAndD/with-noEmitOnError.js
+++ b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/assumeChangesOnlyAffectDirectDependenciesAndD/with-noEmitOnError.js
@@ -43,11 +43,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:32 AM] Found 1 error. Watching for file changes.
 
 
@@ -104,11 +99,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:37 AM] Found 1 error. Watching for file changes.
 
 
diff --git a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/default/with-noEmitOnError-with-incremental.js b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/default/with-noEmitOnError-with-incremental.js
index 46b48bf4ce5..3994e240983 100644
--- a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/default/with-noEmitOnError-with-incremental.js
+++ b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/default/with-noEmitOnError-with-incremental.js
@@ -49,11 +49,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:37 AM] Found 1 error. Watching for file changes.
 
 
@@ -191,11 +186,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:44 AM] Found 1 error. Watching for file changes.
 
 
diff --git a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/default/with-noEmitOnError.js b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/default/with-noEmitOnError.js
index fbb7a7ed574..da78efc9fba 100644
--- a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/default/with-noEmitOnError.js
+++ b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/default/with-noEmitOnError.js
@@ -49,11 +49,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:32 AM] Found 1 error. Watching for file changes.
 
 
@@ -110,11 +105,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:37 AM] Found 1 error. Watching for file changes.
 
 
diff --git a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/defaultAndD/with-noEmitOnError-with-incremental.js b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/defaultAndD/with-noEmitOnError-with-incremental.js
index ba168ab833f..95da55bc583 100644
--- a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/defaultAndD/with-noEmitOnError-with-incremental.js
+++ b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/defaultAndD/with-noEmitOnError-with-incremental.js
@@ -43,11 +43,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:37 AM] Found 1 error. Watching for file changes.
 
 
@@ -186,11 +181,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:44 AM] Found 1 error. Watching for file changes.
 
 
diff --git a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/defaultAndD/with-noEmitOnError.js b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/defaultAndD/with-noEmitOnError.js
index 442f3d18610..3c0a5fcd89b 100644
--- a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/defaultAndD/with-noEmitOnError.js
+++ b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/defaultAndD/with-noEmitOnError.js
@@ -43,11 +43,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:32 AM] Found 1 error. Watching for file changes.
 
 
@@ -104,11 +99,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:37 AM] Found 1 error. Watching for file changes.
 
 
diff --git a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/assumeChangesOnlyAffectDirectDependencies/with-noEmitOnError-with-incremental.js b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/assumeChangesOnlyAffectDirectDependencies/with-noEmitOnError-with-incremental.js
index 13cfbf7708d..eaea5f602e6 100644
--- a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/assumeChangesOnlyAffectDirectDependencies/with-noEmitOnError-with-incremental.js
+++ b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/assumeChangesOnlyAffectDirectDependencies/with-noEmitOnError-with-incremental.js
@@ -43,11 +43,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:37 AM] Found 1 error. Watching for file changes.
 
 
@@ -186,11 +181,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:44 AM] Found 1 error. Watching for file changes.
 
 
diff --git a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/assumeChangesOnlyAffectDirectDependencies/with-noEmitOnError.js b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/assumeChangesOnlyAffectDirectDependencies/with-noEmitOnError.js
index 4a82b0f24e5..105964812e7 100644
--- a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/assumeChangesOnlyAffectDirectDependencies/with-noEmitOnError.js
+++ b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/assumeChangesOnlyAffectDirectDependencies/with-noEmitOnError.js
@@ -43,11 +43,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:37 AM] Found 1 error. Watching for file changes.
 
 
@@ -186,11 +181,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:44 AM] Found 1 error. Watching for file changes.
 
 
diff --git a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/assumeChangesOnlyAffectDirectDependenciesAndD/with-noEmitOnError-with-incremental.js b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/assumeChangesOnlyAffectDirectDependenciesAndD/with-noEmitOnError-with-incremental.js
index 101a14226d2..874eff425a3 100644
--- a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/assumeChangesOnlyAffectDirectDependenciesAndD/with-noEmitOnError-with-incremental.js
+++ b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/assumeChangesOnlyAffectDirectDependenciesAndD/with-noEmitOnError-with-incremental.js
@@ -43,11 +43,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:37 AM] Found 1 error. Watching for file changes.
 
 
@@ -187,11 +182,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:44 AM] Found 1 error. Watching for file changes.
 
 
diff --git a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/assumeChangesOnlyAffectDirectDependenciesAndD/with-noEmitOnError.js b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/assumeChangesOnlyAffectDirectDependenciesAndD/with-noEmitOnError.js
index c90e071624b..bc6607b8d53 100644
--- a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/assumeChangesOnlyAffectDirectDependenciesAndD/with-noEmitOnError.js
+++ b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/assumeChangesOnlyAffectDirectDependenciesAndD/with-noEmitOnError.js
@@ -43,11 +43,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:37 AM] Found 1 error. Watching for file changes.
 
 
@@ -187,11 +182,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:44 AM] Found 1 error. Watching for file changes.
 
 
diff --git a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/default/with-noEmitOnError-with-incremental.js b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/default/with-noEmitOnError-with-incremental.js
index 73fb8a3f99e..1f04fa2e666 100644
--- a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/default/with-noEmitOnError-with-incremental.js
+++ b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/default/with-noEmitOnError-with-incremental.js
@@ -49,11 +49,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:37 AM] Found 1 error. Watching for file changes.
 
 
@@ -191,11 +186,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:44 AM] Found 1 error. Watching for file changes.
 
 
diff --git a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/default/with-noEmitOnError.js b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/default/with-noEmitOnError.js
index 928db04fad6..8d6647dbc4d 100644
--- a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/default/with-noEmitOnError.js
+++ b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/default/with-noEmitOnError.js
@@ -49,11 +49,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:37 AM] Found 1 error. Watching for file changes.
 
 
@@ -191,11 +186,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:44 AM] Found 1 error. Watching for file changes.
 
 
diff --git a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/defaultAndD/with-noEmitOnError-with-incremental.js b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/defaultAndD/with-noEmitOnError-with-incremental.js
index e2394ec3152..29b3348f4df 100644
--- a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/defaultAndD/with-noEmitOnError-with-incremental.js
+++ b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/defaultAndD/with-noEmitOnError-with-incremental.js
@@ -43,11 +43,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:37 AM] Found 1 error. Watching for file changes.
 
 
@@ -186,11 +181,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:44 AM] Found 1 error. Watching for file changes.
 
 
diff --git a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/defaultAndD/with-noEmitOnError.js b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/defaultAndD/with-noEmitOnError.js
index accbfbc36e4..0a5da71c0d0 100644
--- a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/defaultAndD/with-noEmitOnError.js
+++ b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/defaultAndD/with-noEmitOnError.js
@@ -43,11 +43,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:37 AM] Found 1 error. Watching for file changes.
 
 
@@ -186,11 +181,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:44 AM] Found 1 error. Watching for file changes.
 
 
diff --git a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/isolatedModules/with-noEmitOnError-with-incremental.js b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/isolatedModules/with-noEmitOnError-with-incremental.js
index 22e73f151f5..ea636a1de95 100644
--- a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/isolatedModules/with-noEmitOnError-with-incremental.js
+++ b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/isolatedModules/with-noEmitOnError-with-incremental.js
@@ -43,11 +43,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:37 AM] Found 1 error. Watching for file changes.
 
 
@@ -186,11 +181,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:44 AM] Found 1 error. Watching for file changes.
 
 
diff --git a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/isolatedModules/with-noEmitOnError.js b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/isolatedModules/with-noEmitOnError.js
index 59fc6a820f0..62bccd4b4e1 100644
--- a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/isolatedModules/with-noEmitOnError.js
+++ b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/isolatedModules/with-noEmitOnError.js
@@ -43,11 +43,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:37 AM] Found 1 error. Watching for file changes.
 
 
@@ -186,11 +181,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:44 AM] Found 1 error. Watching for file changes.
 
 
diff --git a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/isolatedModulesAndD/with-noEmitOnError-with-incremental.js b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/isolatedModulesAndD/with-noEmitOnError-with-incremental.js
index ea3425d143d..ebda20c91cd 100644
--- a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/isolatedModulesAndD/with-noEmitOnError-with-incremental.js
+++ b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/isolatedModulesAndD/with-noEmitOnError-with-incremental.js
@@ -43,11 +43,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:37 AM] Found 1 error. Watching for file changes.
 
 
@@ -187,11 +182,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:44 AM] Found 1 error. Watching for file changes.
 
 
diff --git a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/isolatedModulesAndD/with-noEmitOnError.js b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/isolatedModulesAndD/with-noEmitOnError.js
index ddff239e3c9..81d203d04cd 100644
--- a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/isolatedModulesAndD/with-noEmitOnError.js
+++ b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/incremental/isolatedModulesAndD/with-noEmitOnError.js
@@ -43,11 +43,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:37 AM] Found 1 error. Watching for file changes.
 
 
@@ -187,11 +182,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:44 AM] Found 1 error. Watching for file changes.
 
 
diff --git a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/isolatedModules/with-noEmitOnError-with-incremental.js b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/isolatedModules/with-noEmitOnError-with-incremental.js
index daf7e2b9e0f..18759a8a9c6 100644
--- a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/isolatedModules/with-noEmitOnError-with-incremental.js
+++ b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/isolatedModules/with-noEmitOnError-with-incremental.js
@@ -43,11 +43,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:37 AM] Found 1 error. Watching for file changes.
 
 
@@ -186,11 +181,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:44 AM] Found 1 error. Watching for file changes.
 
 
diff --git a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/isolatedModules/with-noEmitOnError.js b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/isolatedModules/with-noEmitOnError.js
index 4093ad48302..48c8bcb5bd3 100644
--- a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/isolatedModules/with-noEmitOnError.js
+++ b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/isolatedModules/with-noEmitOnError.js
@@ -43,11 +43,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:32 AM] Found 1 error. Watching for file changes.
 
 
@@ -104,11 +99,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:37 AM] Found 1 error. Watching for file changes.
 
 
diff --git a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/isolatedModulesAndD/with-noEmitOnError-with-incremental.js b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/isolatedModulesAndD/with-noEmitOnError-with-incremental.js
index b6323d2ed80..27bfca04dbd 100644
--- a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/isolatedModulesAndD/with-noEmitOnError-with-incremental.js
+++ b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/isolatedModulesAndD/with-noEmitOnError-with-incremental.js
@@ -43,11 +43,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:37 AM] Found 1 error. Watching for file changes.
 
 
@@ -187,11 +182,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:44 AM] Found 1 error. Watching for file changes.
 
 
diff --git a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/isolatedModulesAndD/with-noEmitOnError.js b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/isolatedModulesAndD/with-noEmitOnError.js
index 659ad657153..0969d50832b 100644
--- a/tests/baselines/reference/tscWatch/emitAndErrorUpdates/isolatedModulesAndD/with-noEmitOnError.js
+++ b/tests/baselines/reference/tscWatch/emitAndErrorUpdates/isolatedModulesAndD/with-noEmitOnError.js
@@ -43,11 +43,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:32 AM] Found 1 error. Watching for file changes.
 
 
@@ -104,11 +99,6 @@ Output::
 4 ;
   ~
 
-  src/main.ts:2:11
-    2 const a = {
-                ~
-    The parser expected to find a '}' to match the '{' token here.
-
 [12:00:37 AM] Found 1 error. Watching for file changes.
 
 
diff --git a/tests/baselines/reference/typeAssertions.errors.txt b/tests/baselines/reference/typeAssertions.errors.txt
index 9d10ec17fe9..cf132a12d02 100644
--- a/tests/baselines/reference/typeAssertions.errors.txt
+++ b/tests/baselines/reference/typeAssertions.errors.txt
@@ -93,6 +93,7 @@ tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts(48,50): err
 !!! error TS2304: Cannot find name 'is'.
                     ~~~~~~
 !!! error TS1005: ')' expected.
+!!! related TS1007 tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts:44:3: The parser expected to find a ')' to match the '(' token here.
                     ~~~~~~
 !!! error TS2693: 'string' only refers to a type, but is being used as a value here.
                                                    ~
@@ -108,6 +109,7 @@ tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts(48,50): err
 !!! error TS2749: 'numOrStr' refers to a value, but is being used as a type here. Did you mean 'typeof numOrStr'?
                                             ~~
 !!! error TS1005: ')' expected.
+!!! related TS1007 tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts:48:3: The parser expected to find a ')' to match the '(' token here.
                                             ~~
 !!! error TS2304: Cannot find name 'is'.
                                                ~~~~~~
diff --git a/tests/cases/compiler/destructionAssignmentError.ts b/tests/cases/compiler/destructionAssignmentError.ts
new file mode 100644
index 00000000000..6845391d659
--- /dev/null
+++ b/tests/cases/compiler/destructionAssignmentError.ts
@@ -0,0 +1,12 @@
+declare function fn(): { a: 1, b: 2 }
+let a: number;
+let b: number;
+
+({ a, b } = fn());
+{ a, b } = fn();
+
+({ a, b } =
+fn());
+
+{ a, b }
+= fn();
\ No newline at end of file
diff --git a/tests/cases/compiler/missingCloseBracketInArray.ts b/tests/cases/compiler/missingCloseBracketInArray.ts
new file mode 100644
index 00000000000..cb99f0d2277
--- /dev/null
+++ b/tests/cases/compiler/missingCloseBracketInArray.ts
@@ -0,0 +1 @@
+var alphas:string[] = alphas = ["1","2","3","4"
\ No newline at end of file
diff --git a/tests/cases/compiler/missingCloseParenStatements.ts b/tests/cases/compiler/missingCloseParenStatements.ts
new file mode 100644
index 00000000000..7ff34bdae6a
--- /dev/null
+++ b/tests/cases/compiler/missingCloseParenStatements.ts
@@ -0,0 +1,13 @@
+var a1, a2, a3 = 0;
+if ( a1 && (a2 + a3 > 0) {
+    while( (a2 > 0) && a1
+    {
+        do {
+            var i = i + 1;
+            a1 = a1 + i;
+            with ((a2 + a3 > 0) && a1 {
+                console.log(x);
+              }
+        } while (i < 5 && (a1 > 5);
+    }
+}
\ No newline at end of file
diff --git a/tests/cases/conformance/classes/propertyMemberDeclarations/redeclaredProperty.ts b/tests/cases/conformance/classes/propertyMemberDeclarations/redeclaredProperty.ts
new file mode 100644
index 00000000000..4080146e028
--- /dev/null
+++ b/tests/cases/conformance/classes/propertyMemberDeclarations/redeclaredProperty.ts
@@ -0,0 +1,17 @@
+// @noTypesAndSymbols: true
+// @strictNullChecks: true
+// @target: esnext
+// @useDefineForClassFields: true
+class Base {
+  b = 1;
+}
+
+class Derived extends Base {
+  b;
+  d = this.b;
+
+  constructor() {
+    super();
+    this.b = 2;
+  }
+}
diff --git a/tests/cases/conformance/classes/propertyMemberDeclarations/redefinedPararameterProperty.ts b/tests/cases/conformance/classes/propertyMemberDeclarations/redefinedPararameterProperty.ts
new file mode 100644
index 00000000000..02eabfbfcfa
--- /dev/null
+++ b/tests/cases/conformance/classes/propertyMemberDeclarations/redefinedPararameterProperty.ts
@@ -0,0 +1,16 @@
+// @noTypesAndSymbols: true
+// @strictNullChecks: true
+// @target: esnext
+// @useDefineForClassFields: true
+class Base {
+    a = 1;
+  }
+  
+  class Derived extends Base {
+    b = this.a /*undefined*/;
+  
+    constructor(public a: number) {
+        super();
+    }
+  }
+  
\ No newline at end of file
diff --git a/tests/cases/conformance/interfaces/interfaceDeclarations/interfacesWithPredefinedTypesAsNames.ts b/tests/cases/conformance/interfaces/interfaceDeclarations/interfacesWithPredefinedTypesAsNames.ts
index 56bbaa62e36..edd53d2cdfc 100644
--- a/tests/cases/conformance/interfaces/interfaceDeclarations/interfacesWithPredefinedTypesAsNames.ts
+++ b/tests/cases/conformance/interfaces/interfaceDeclarations/interfacesWithPredefinedTypesAsNames.ts
@@ -2,4 +2,6 @@ interface any { }
 interface number { }
 interface string { }
 interface boolean { }
-interface void {}
\ No newline at end of file
+interface void {}
+interface unknown {}
+interface never {}
\ No newline at end of file
diff --git a/tests/cases/conformance/parser/ecmascript5/ErrorRecovery/ArrayLiteralExpressions/parserErrorRecoveryArrayLiteralExpression3.ts b/tests/cases/conformance/parser/ecmascript5/ErrorRecovery/ArrayLiteralExpressions/parserErrorRecoveryArrayLiteralExpression3.ts
index 58df0691d8e..18ed3b5ef5a 100644
--- a/tests/cases/conformance/parser/ecmascript5/ErrorRecovery/ArrayLiteralExpressions/parserErrorRecoveryArrayLiteralExpression3.ts
+++ b/tests/cases/conformance/parser/ecmascript5/ErrorRecovery/ArrayLiteralExpressions/parserErrorRecoveryArrayLiteralExpression3.ts
@@ -1,2 +1 @@
-
 var texCoords = [2, 2, 0.5000001192092895, 0.8749999 ; 403953552, 0.5000001192092895, 0.8749999403953552];
diff --git a/tests/cases/conformance/types/literal/templateLiteralTypes2.ts b/tests/cases/conformance/types/literal/templateLiteralTypes2.ts
index 75ab1485a05..5e51c5b30b2 100644
--- a/tests/cases/conformance/types/literal/templateLiteralTypes2.ts
+++ b/tests/cases/conformance/types/literal/templateLiteralTypes2.ts
@@ -113,3 +113,9 @@ const pixelStringWithTemplate: PixelValueType = `${pixelValue}px`;
 function getCardTitle(title: string): `test-${string}` {
     return `test-${title}`;
 }
+
+// Repro from #43424
+
+const interpolatedStyle = { rotate: 12 };
+function C2(transform: "-moz-initial" | (string & {})) { return 12; }
+C2(`rotate(${interpolatedStyle.rotate}dig)`);
diff --git a/tests/cases/fourslash/findAllRefsJsDocTypeDef_js.ts b/tests/cases/fourslash/findAllRefsJsDocTypeDef_js.ts
index 844c2532775..fb3cdf5bc33 100644
--- a/tests/cases/fourslash/findAllRefsJsDocTypeDef_js.ts
+++ b/tests/cases/fourslash/findAllRefsJsDocTypeDef_js.ts
@@ -5,7 +5,7 @@
 // @allowJs: true
 
 // @Filename: /a.js
-/////** [|@typedef {number} [|{| "isWriteAccess": true, "isDefinition": true, "contextRangeIndex": 0 |}T|] |]*/
+/////** [|@typedef {number} [|{| "isWriteAccess": true, "isDefinition": true, "contextRangeIndex": 0 |}T|]|] */
 ////
 /////**
 //// * @return {[|T|]}
diff --git a/tests/cases/fourslash/findAllRefsTypedef_importType.ts b/tests/cases/fourslash/findAllRefsTypedef_importType.ts
index f84632d729d..4816406d518 100644
--- a/tests/cases/fourslash/findAllRefsTypedef_importType.ts
+++ b/tests/cases/fourslash/findAllRefsTypedef_importType.ts
@@ -4,7 +4,7 @@
 
 // @Filename: /a.js
 ////module.exports = 0;
-/////** [|@typedef {number} [|{| "isWriteAccess": true, "isDefinition": true, "contextRangeIndex": 0 |}Foo|] |]*/
+/////** [|@typedef {number} [|{| "isWriteAccess": true, "isDefinition": true, "contextRangeIndex": 0 |}Foo|]|] */
 ////const dummy = 0;
 
 // @Filename: /b.js
diff --git a/tests/cases/fourslash/jsDocSignature-43394.ts b/tests/cases/fourslash/jsDocSignature-43394.ts
new file mode 100644
index 00000000000..3091c8e5a4b
--- /dev/null
+++ b/tests/cases/fourslash/jsDocSignature-43394.ts
@@ -0,0 +1,9 @@
+///<reference path="fourslash.ts" />
+
+/////**
+//// * @typedef {Object} Foo
+//// * @property {number} ...
+//// * /**/@typedef {number} Bar
+//// */
+
+verify.baselineSignatureHelp();
diff --git a/tests/cases/fourslash/jsdocTypedefTagSemanticMeaning0.ts b/tests/cases/fourslash/jsdocTypedefTagSemanticMeaning0.ts
index 4d4bb63058f..44156116d2f 100644
--- a/tests/cases/fourslash/jsdocTypedefTagSemanticMeaning0.ts
+++ b/tests/cases/fourslash/jsdocTypedefTagSemanticMeaning0.ts
@@ -3,7 +3,7 @@
 // @allowJs: true
 // @Filename: a.js
 
-/////** [|@typedef {number} [|{| "isWriteAccess": true, "isDefinition": true, "contextRangeIndex": 0 |}T|] |]*/
+/////** [|@typedef {number} [|{| "isWriteAccess": true, "isDefinition": true, "contextRangeIndex": 0 |}T|]|] */
 
 ////[|const [|{| "isWriteAccess": true, "isDefinition": true, "contextRangeIndex": 2 |}T|] = 1;|]
 
diff --git a/tests/cases/fourslash/refactorAddOrRemoveBracesToArrowFunction29.ts b/tests/cases/fourslash/refactorAddOrRemoveBracesToArrowFunction29.ts
new file mode 100644
index 00000000000..b189082832e
--- /dev/null
+++ b/tests/cases/fourslash/refactorAddOrRemoveBracesToArrowFunction29.ts
@@ -0,0 +1,13 @@
+/// <reference path='fourslash.ts' />
+
+////const a = /*a*/()/*b*/ => {
+////    return {} as {}
+////};
+
+goTo.select("a", "b");
+edit.applyRefactor({
+    refactorName: "Add or remove braces in an arrow function",
+    actionName: "Remove braces from arrow function",
+    actionDescription: "Remove braces from arrow function",
+    newContent: `const a = () => ({} as {});`,
+});
diff --git a/tests/cases/fourslash/refactorAddOrRemoveBracesToArrowFunction30.ts b/tests/cases/fourslash/refactorAddOrRemoveBracesToArrowFunction30.ts
new file mode 100644
index 00000000000..0cef0c3c7fe
--- /dev/null
+++ b/tests/cases/fourslash/refactorAddOrRemoveBracesToArrowFunction30.ts
@@ -0,0 +1,13 @@
+/// <reference path='fourslash.ts' />
+
+////const a = /*a*/()/*b*/ => {
+////    return {} as object
+////};
+
+goTo.select("a", "b");
+edit.applyRefactor({
+    refactorName: "Add or remove braces in an arrow function",
+    actionName: "Remove braces from arrow function",
+    actionDescription: "Remove braces from arrow function",
+    newContent: `const a = () => ({} as object);`,
+});
diff --git a/tests/cases/fourslash/refactorConvertToEs6Module_import_es6DefaultImport.ts b/tests/cases/fourslash/refactorConvertToEs6Module_import_es6DefaultImport.ts
new file mode 100644
index 00000000000..9fe26a24010
--- /dev/null
+++ b/tests/cases/fourslash/refactorConvertToEs6Module_import_es6DefaultImport.ts
@@ -0,0 +1,19 @@
+/// <reference path='fourslash.ts' />
+
+// @allowJs: true
+// @target: esnext
+
+// @Filename: /a.js
+////const x = require('x');
+////x.default();
+////const y = require('y').default;
+////y();
+
+verify.codeFix({
+    description: "Convert to ES6 module",
+    newFileContent:
+`import x from 'x';
+x();
+import y from 'y';
+y();`,
+});
diff --git a/tests/cases/fourslash/server/jsdocTypedefTagRename02.ts b/tests/cases/fourslash/server/jsdocTypedefTagRename02.ts
index 45bfd871aea..30c99deb0a8 100644
--- a/tests/cases/fourslash/server/jsdocTypedefTagRename02.ts
+++ b/tests/cases/fourslash/server/jsdocTypedefTagRename02.ts
@@ -3,7 +3,7 @@
 // @allowNonTsExtensions: true
 // @Filename: jsDocTypedef_form2.js
 ////
-//// /** [|@typedef {(string | number)} [|{| "contextRangeIndex": 0 |}NumberLike|] |]*/
+//// /** [|@typedef {(string | number)} [|{| "contextRangeIndex": 0 |}NumberLike|]|] */
 ////
 //// /** @type {[|NumberLike|]} */
 //// var numberLike;