Ensure generated property names for methods named "new" are quoted

src/compiler/checker.ts

@@ -8213,16 +8213,17 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         function getPropertyNameNodeForSymbol(symbol: Symbol, context: NodeBuilderContext) {
             const stringNamed = !!length(symbol.declarations) && every(symbol.declarations, isStringNamed);
             const singleQuote = !!length(symbol.declarations) && every(symbol.declarations, isSingleQuotedStringNamed);
-            const fromNameType = getPropertyNameNodeForSymbolFromNameType(symbol, context, singleQuote, stringNamed);
+            const isMethod = !!(symbol.flags & SymbolFlags.Method);
+            const fromNameType = getPropertyNameNodeForSymbolFromNameType(symbol, context, singleQuote, stringNamed, isMethod);
             if (fromNameType) {
                 return fromNameType;
             }
             const rawName = unescapeLeadingUnderscores(symbol.escapedName);
-            return createPropertyNameNodeForIdentifierOrLiteral(rawName, getEmitScriptTarget(compilerOptions), singleQuote, stringNamed);
+            return createPropertyNameNodeForIdentifierOrLiteral(rawName, getEmitScriptTarget(compilerOptions), singleQuote, stringNamed, isMethod);
         }
 
         // See getNameForSymbolFromNameType for a stringy equivalent
-        function getPropertyNameNodeForSymbolFromNameType(symbol: Symbol, context: NodeBuilderContext, singleQuote?: boolean, stringNamed?: boolean) {
+        function getPropertyNameNodeForSymbolFromNameType(symbol: Symbol, context: NodeBuilderContext, singleQuote: boolean, stringNamed: boolean, isMethod: boolean) {
             const nameType = getSymbolLinks(symbol).nameType;
             if (nameType) {
                 if (nameType.flags & TypeFlags.StringOrNumberLiteral) {
@@ -8233,7 +8234,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                     if (isNumericLiteralName(name) && startsWith(name, "-")) {
                         return factory.createComputedPropertyName(factory.createPrefixUnaryExpression(SyntaxKind.MinusToken, factory.createNumericLiteral(Math.abs(+name))));
                     }
-                    return createPropertyNameNodeForIdentifierOrLiteral(name, getEmitScriptTarget(compilerOptions));
+                    return createPropertyNameNodeForIdentifierOrLiteral(name, getEmitScriptTarget(compilerOptions), singleQuote, stringNamed, isMethod);
                 }
                 if (nameType.flags & TypeFlags.UniqueESSymbol) {
                     return factory.createComputedPropertyName(symbolToExpression((nameType as UniqueESSymbolType).symbol, context, SymbolFlags.Value));

src/compiler/utilities.ts

@@ -10216,9 +10216,10 @@ export function isNumericLiteralName(name: string | __String) {
 }
 
 /** @internal */
-export function createPropertyNameNodeForIdentifierOrLiteral(name: string, target: ScriptTarget, singleQuote?: boolean, stringNamed?: boolean) {
-    return isIdentifierText(name, target) ? factory.createIdentifier(name) :
-        !stringNamed && isNumericLiteralName(name) && +name >= 0 ? factory.createNumericLiteral(+name) :
+export function createPropertyNameNodeForIdentifierOrLiteral(name: string, target: ScriptTarget, singleQuote: boolean, stringNamed: boolean, isMethod: boolean) {
+    const isMethodNamedNew = isMethod && name === "new";
+    return !isMethodNamedNew && isIdentifierText(name, target) ? factory.createIdentifier(name) :
+        !stringNamed && !isMethodNamedNew && isNumericLiteralName(name) && +name >= 0 ? factory.createNumericLiteral(+name) :
         factory.createStringLiteral(name, !!singleQuote);
 }
 

src/services/codefixes/fixAddMissingMember.ts

@@ -772,7 +772,8 @@ function createPropertyNameFromSymbol(symbol: Symbol, target: ScriptTarget, quot
         const prop = checker.symbolToNode(symbol, SymbolFlags.Value, /*enclosingDeclaration*/ undefined, NodeBuilderFlags.WriteComputedProps);
         if (prop && isComputedPropertyName(prop)) return prop;
     }
-    return createPropertyNameNodeForIdentifierOrLiteral(symbol.name, target, quotePreference === QuotePreference.Single);
+    // We're using these nodes as property names in an object literal; no need to quote names when not needed.
+    return createPropertyNameNodeForIdentifierOrLiteral(symbol.name, target, quotePreference === QuotePreference.Single, /*stringNamed*/ false, /*isMethod*/ false);
 }
 
 function findScope(node: Node) {

tests/baselines/reference/emitMethodCalledNew.js

@@ -0,0 +1,43 @@
+//// [tests/cases/compiler/emitMethodCalledNew.ts] ////
+
+//// [emitMethodCalledNew.ts]
+// https://github.com/microsoft/TypeScript/issues/55075
+
+export const a = {
+  new(x: number) { return x + 1 }
+}
+export const b = {
+  "new"(x: number) { return x + 1 }
+}
+export const c = {
+  ["new"](x: number) { return x + 1 }
+}
+
+
+//// [emitMethodCalledNew.js]
+"use strict";
+// https://github.com/microsoft/TypeScript/issues/55075
+var _a;
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.c = exports.b = exports.a = void 0;
+exports.a = {
+    new: function (x) { return x + 1; }
+};
+exports.b = {
+    "new": function (x) { return x + 1; }
+};
+exports.c = (_a = {},
+    _a["new"] = function (x) { return x + 1; },
+    _a);
+
+
+//// [emitMethodCalledNew.d.ts]
+export declare const a: {
+    "new"(x: number): number;
+};
+export declare const b: {
+    "new"(x: number): number;
+};
+export declare const c: {
+    "new"(x: number): number;
+};

tests/baselines/reference/emitMethodCalledNew.symbols

@@ -0,0 +1,31 @@
+//// [tests/cases/compiler/emitMethodCalledNew.ts] ////
+
+=== emitMethodCalledNew.ts ===
+// https://github.com/microsoft/TypeScript/issues/55075
+
+export const a = {
+>a : Symbol(a, Decl(emitMethodCalledNew.ts, 2, 12))
+
+  new(x: number) { return x + 1 }
+>new : Symbol(new, Decl(emitMethodCalledNew.ts, 2, 18))
+>x : Symbol(x, Decl(emitMethodCalledNew.ts, 3, 6))
+>x : Symbol(x, Decl(emitMethodCalledNew.ts, 3, 6))
+}
+export const b = {
+>b : Symbol(b, Decl(emitMethodCalledNew.ts, 5, 12))
+
+  "new"(x: number) { return x + 1 }
+>"new" : Symbol("new", Decl(emitMethodCalledNew.ts, 5, 18))
+>x : Symbol(x, Decl(emitMethodCalledNew.ts, 6, 8))
+>x : Symbol(x, Decl(emitMethodCalledNew.ts, 6, 8))
+}
+export const c = {
+>c : Symbol(c, Decl(emitMethodCalledNew.ts, 8, 12))
+
+  ["new"](x: number) { return x + 1 }
+>["new"] : Symbol(["new"], Decl(emitMethodCalledNew.ts, 8, 18))
+>"new" : Symbol(["new"], Decl(emitMethodCalledNew.ts, 8, 18))
+>x : Symbol(x, Decl(emitMethodCalledNew.ts, 9, 10))
+>x : Symbol(x, Decl(emitMethodCalledNew.ts, 9, 10))
+}
+

tests/baselines/reference/emitMethodCalledNew.types

@@ -0,0 +1,40 @@
+//// [tests/cases/compiler/emitMethodCalledNew.ts] ////
+
+=== emitMethodCalledNew.ts ===
+// https://github.com/microsoft/TypeScript/issues/55075
+
+export const a = {
+>a : { "new"(x: number): number; }
+>{  new(x: number) { return x + 1 }} : { "new"(x: number): number; }
+
+  new(x: number) { return x + 1 }
+>new : (x: number) => number
+>x : number
+>x + 1 : number
+>x : number
+>1 : 1
+}
+export const b = {
+>b : { "new"(x: number): number; }
+>{  "new"(x: number) { return x + 1 }} : { "new"(x: number): number; }
+
+  "new"(x: number) { return x + 1 }
+>"new" : (x: number) => number
+>x : number
+>x + 1 : number
+>x : number
+>1 : 1
+}
+export const c = {
+>c : { "new"(x: number): number; }
+>{  ["new"](x: number) { return x + 1 }} : { "new"(x: number): number; }
+
+  ["new"](x: number) { return x + 1 }
+>["new"] : (x: number) => number
+>"new" : "new"
+>x : number
+>x + 1 : number
+>x : number
+>1 : 1
+}
+

tests/baselines/reference/objectTypesIdentityWithConstructSignatures2.types

@@ -32,8 +32,8 @@ var a: { new(x: Date): string }
 >x : Date
 
 var b = { new(x: RegExp) { return ''; } }; // not a construct signature, function called new
->b : { new(x: RegExp): string; }
->{ new(x: RegExp) { return ''; } } : { new(x: RegExp): string; }
+>b : { "new"(x: RegExp): string; }
+>{ new(x: RegExp) { return ''; } } : { "new"(x: RegExp): string; }
 >new : (x: RegExp) => string
 >x : RegExp
 >'' : ""
@@ -89,17 +89,17 @@ function foo3(x: any) { }
 >x : any
 
 function foo4(x: typeof b);
->foo4 : { (x: typeof b): any; (x: { new(x: RegExp): string; }): any; }
->x : { new(x: RegExp): string; }
->b : { new(x: RegExp): string; }
+>foo4 : { (x: typeof b): any; (x: { "new"(x: RegExp): string; }): any; }
+>x : { "new"(x: RegExp): string; }
+>b : { "new"(x: RegExp): string; }
 
 function foo4(x: typeof b); // error
->foo4 : { (x: { new(x: RegExp): string; }): any; (x: typeof b): any; }
->x : { new(x: RegExp): string; }
->b : { new(x: RegExp): string; }
+>foo4 : { (x: { "new"(x: RegExp): string; }): any; (x: typeof b): any; }
+>x : { "new"(x: RegExp): string; }
+>b : { "new"(x: RegExp): string; }
 
 function foo4(x: any) { }
->foo4 : { (x: { new(x: RegExp): string; }): any; (x: { new(x: RegExp): string; }): any; }
+>foo4 : { (x: { "new"(x: RegExp): string; }): any; (x: { "new"(x: RegExp): string; }): any; }
 >x : any
 
 function foo8(x: B);
@@ -140,16 +140,16 @@ function foo10(x: any) { }
 >x : any
 
 function foo11(x: B);
->foo11 : { (x: B): any; (x: { new(x: RegExp): string; }): any; }
+>foo11 : { (x: B): any; (x: { "new"(x: RegExp): string; }): any; }
 >x : B
 
 function foo11(x: typeof b); // ok
 >foo11 : { (x: B): any; (x: typeof b): any; }
->x : { new(x: RegExp): string; }
->b : { new(x: RegExp): string; }
+>x : { "new"(x: RegExp): string; }
+>b : { "new"(x: RegExp): string; }
 
 function foo11(x: any) { }
->foo11 : { (x: B): any; (x: { new(x: RegExp): string; }): any; }
+>foo11 : { (x: B): any; (x: { "new"(x: RegExp): string; }): any; }
 >x : any
 
 function foo12(x: I);
@@ -190,16 +190,16 @@ function foo13(x: any) { }
 >x : any
 
 function foo14(x: I);
->foo14 : { (x: I): any; (x: { new(x: RegExp): string; }): any; }
+>foo14 : { (x: I): any; (x: { "new"(x: RegExp): string; }): any; }
 >x : I
 
 function foo14(x: typeof b); // ok
 >foo14 : { (x: I): any; (x: typeof b): any; }
->x : { new(x: RegExp): string; }
->b : { new(x: RegExp): string; }
+>x : { "new"(x: RegExp): string; }
+>b : { "new"(x: RegExp): string; }
 
 function foo14(x: any) { }
->foo14 : { (x: I): any; (x: { new(x: RegExp): string; }): any; }
+>foo14 : { (x: I): any; (x: { "new"(x: RegExp): string; }): any; }
 >x : any
 
 function foo15(x: I2<string>);

tests/baselines/reference/objectTypesIdentityWithConstructSignaturesDifferingParamCounts.types

@@ -35,8 +35,8 @@ var a: { new(x: string, y: string): string }
 >y : string
 
 var b = { new(x: string) { return ''; } }; // not a construct signature, function called new
->b : { new(x: string): string; }
->{ new(x: string) { return ''; } } : { new(x: string): string; }
+>b : { "new"(x: string): string; }
+>{ new(x: string) { return ''; } } : { "new"(x: string): string; }
 >new : (x: string) => string
 >x : string
 >'' : ""
@@ -92,17 +92,17 @@ function foo3(x: any) { }
 >x : any
 
 function foo4(x: typeof b);
->foo4 : { (x: typeof b): any; (x: { new(x: string): string; }): any; }
->x : { new(x: string): string; }
->b : { new(x: string): string; }
+>foo4 : { (x: typeof b): any; (x: { "new"(x: string): string; }): any; }
+>x : { "new"(x: string): string; }
+>b : { "new"(x: string): string; }
 
 function foo4(x: typeof b); // error
->foo4 : { (x: { new(x: string): string; }): any; (x: typeof b): any; }
->x : { new(x: string): string; }
->b : { new(x: string): string; }
+>foo4 : { (x: { "new"(x: string): string; }): any; (x: typeof b): any; }
+>x : { "new"(x: string): string; }
+>b : { "new"(x: string): string; }
 
 function foo4(x: any) { }
->foo4 : { (x: { new(x: string): string; }): any; (x: { new(x: string): string; }): any; }
+>foo4 : { (x: { "new"(x: string): string; }): any; (x: { "new"(x: string): string; }): any; }
 >x : any
 
 function foo8(x: B);
@@ -143,16 +143,16 @@ function foo10(x: any) { }
 >x : any
 
 function foo11(x: B);
->foo11 : { (x: B): any; (x: { new(x: string): string; }): any; }
+>foo11 : { (x: B): any; (x: { "new"(x: string): string; }): any; }
 >x : B
 
 function foo11(x: typeof b); // ok
 >foo11 : { (x: B): any; (x: typeof b): any; }
->x : { new(x: string): string; }
->b : { new(x: string): string; }
+>x : { "new"(x: string): string; }
+>b : { "new"(x: string): string; }
 
 function foo11(x: any) { }
->foo11 : { (x: B): any; (x: { new(x: string): string; }): any; }
+>foo11 : { (x: B): any; (x: { "new"(x: string): string; }): any; }
 >x : any
 
 function foo12(x: I);
@@ -193,16 +193,16 @@ function foo13(x: any) { }
 >x : any
 
 function foo14(x: I);
->foo14 : { (x: I): any; (x: { new(x: string): string; }): any; }
+>foo14 : { (x: I): any; (x: { "new"(x: string): string; }): any; }
 >x : I
 
 function foo14(x: typeof b); // ok
 >foo14 : { (x: I): any; (x: typeof b): any; }
->x : { new(x: string): string; }
->b : { new(x: string): string; }
+>x : { "new"(x: string): string; }
+>b : { "new"(x: string): string; }
 
 function foo14(x: any) { }
->foo14 : { (x: I): any; (x: { new(x: string): string; }): any; }
+>foo14 : { (x: I): any; (x: { "new"(x: string): string; }): any; }
 >x : any
 
 function foo15(x: I2<string>);