Add support for pedantic property access (#40171)

* Add support for pedantic property access

* accept baseline

* Update diag message

* Avoid pedantic

Co-authored-by: Nathan Shively-Sanders <293473+sandersn@users.noreply.github.com>

src/compiler/checker.ts

@@ -25865,6 +25865,9 @@ namespace ts {
                 }
 
                 propType = (compilerOptions.noUncheckedIndexedAccess && !isAssignmentTarget(node)) ? getUnionType([indexInfo.type, undefinedType]) : indexInfo.type;
+                if (compilerOptions.noPropertyAccessFromIndexSignature && isPropertyAccessExpression(node)) {
+                    error(node, Diagnostics.Property_0_comes_from_an_index_signature_so_it_must_be_accessed_with_0, unescapeLeadingUnderscores(right.escapedText));
+                }
             }
             else {
                 if (getDeclarationNodeFlagsFromSymbol(prop) & NodeFlags.Deprecated && isUncalledFunctionReference(node, prop)) {

src/compiler/commandLineParser.ts

@@ -635,6 +635,15 @@ namespace ts {
             category: Diagnostics.Additional_Checks,
             description: Diagnostics.Include_undefined_in_index_signature_results
         },
+        {
+            name: "noPropertyAccessFromIndexSignature",
+            type: "boolean",
+            affectsBindDiagnostics: true,
+            affectsSemanticDiagnostics: true,
+            showInSimplifiedHelpView: false,
+            category: Diagnostics.Additional_Checks,
+            description: Diagnostics.Require_undeclared_properties_from_index_signatures_to_use_element_accesses
+        },
 
         // Module Resolution
         {

src/compiler/diagnosticMessages.json

@@ -3428,6 +3428,10 @@
         "category": "Error",
         "code": 4110
     },
+    "Property '{0}' comes from an index signature, so it must be accessed with ['{0}'].": {
+        "category": "Error",
+        "code": 4111
+    },
 
     "The current host does not support the '{0}' option.": {
         "category": "Error",
@@ -4744,6 +4748,10 @@
         "category": "Error",
         "code": 6504
     },
+    "Require undeclared properties from index signatures to use element accesses.": {
+        "category": "Error",
+        "code": 6803
+    },
 
     "Include 'undefined' in index signature results": {
         "category": "Message",
@@ -5959,10 +5967,18 @@
         "category": "Message",
         "code": 95144
     },
-    "Delete all unused imports": {
+    "Use element access for '{0}'": {
         "category": "Message",
         "code": 95145
     },
+    "Use element access for all undeclared properties.": {
+        "category": "Message",
+        "code": 95146
+    },
+    "Delete all unused imports": {
+        "category": "Message",
+        "code": 95147
+    },
 
     "No value exists in scope for the shorthand property '{0}'. Either declare one or provide an initializer.": {
         "category": "Error",

src/compiler/types.ts

@@ -5784,6 +5784,7 @@ namespace ts {
         noUnusedLocals?: boolean;
         noUnusedParameters?: boolean;
         noImplicitUseStrict?: boolean;
+        noPropertyAccessFromIndexSignature?: boolean;
         assumeChangesOnlyAffectDirectDependencies?: boolean;
         noLib?: boolean;
         noResolve?: boolean;

src/services/codefixes/fixNoPropertyAccessFromIndexSignature.ts

@@ -0,0 +1,35 @@
+/* @internal */
+namespace ts.codefix {
+    const fixId = "fixNoPropertyAccessFromIndexSignature";
+    const errorCodes = [
+        Diagnostics.Property_0_comes_from_an_index_signature_so_it_must_be_accessed_with_0.code
+    ];
+
+    registerCodeFix({
+        errorCodes,
+        fixIds: [fixId],
+        getCodeActions(context) {
+            const { sourceFile, span } = context;
+            const property = getPropertyAccessExpression(sourceFile, span.start);
+            const changes = textChanges.ChangeTracker.with(context, t => doChange(t, context.sourceFile, property));
+            return [createCodeFixAction(fixId, changes, [Diagnostics.Use_element_access_for_0, property.name.text], fixId, Diagnostics.Use_element_access_for_all_undeclared_properties)];
+        },
+        getAllCodeActions: context =>
+            codeFixAll(context, errorCodes, (changes, diag) => doChange(changes, diag.file, getPropertyAccessExpression(diag.file, diag.start)))
+    });
+
+    function doChange(changes: textChanges.ChangeTracker, sourceFile: SourceFile, node: PropertyAccessExpression): void {
+        const argumentsExpression = factory.createStringLiteral(node.name.text);
+        changes.replaceNode(
+            sourceFile,
+            node,
+            isPropertyAccessChain(node) ?
+                factory.createElementAccessChain(node.expression, node.questionDotToken, argumentsExpression) :
+                factory.createElementAccessExpression(node.expression, argumentsExpression)
+        );
+    }
+
+    function getPropertyAccessExpression(sourceFile: SourceFile, pos: number): PropertyAccessExpression {
+        return cast(getTokenAtPosition(sourceFile, pos).parent, isPropertyAccessExpression);
+    }
+}

src/services/tsconfig.json

@@ -65,6 +65,7 @@
         "codefixes/convertLiteralTypeToMappedType.ts",
         "codefixes/fixClassIncorrectlyImplementsInterface.ts",
         "codefixes/importFixes.ts",
+        "codefixes/fixNoPropertyAccessFromIndexSignature.ts",
         "codefixes/fixImplicitThis.ts",
         "codefixes/fixIncorrectNamedTupleSyntax.ts",
         "codefixes/fixSpelling.ts",