Normalize reused string-literal property names to identifiers in declaration emit (#3965)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: jakebailey <5341706+jakebailey@users.noreply.github.com>

Author: Copilot

internal/checker/nodecopy.go

@@ -7,6 +7,7 @@ import (
 	"github.com/microsoft/typescript-go/internal/core"
 	"github.com/microsoft/typescript-go/internal/nodebuilder"
 	"github.com/microsoft/typescript-go/internal/printer"
+	"github.com/microsoft/typescript-go/internal/scanner"
 )
 
 func (b *NodeBuilderImpl) reuseNode(node *ast.Node) *ast.Node {
@@ -21,14 +22,34 @@ func (b *NodeBuilderImpl) tryJSTypeNodeToTypeNode(node *ast.Node) *ast.Node {
 	return b.reuseNode(node)
 }
 
-// a wrapper around `reuseNode` that handles renaming `new` to `"new"` so we don't accidentally emit constructor signatures when we don't mean to
+// a wrapper around `reuseNode` for property names. It handles renaming `new` to `"new"` so we don't
+// accidentally emit constructor signatures when we don't mean to, and normalizes string-literal
+// property names whose text is a valid identifier into identifiers, matching the behavior of
+// `createPropertyNameNodeForIdentifierOrLiteral` used when constructing fresh property name nodes
+// (so that reused names emit consistently regardless of whether their containing type was reused
+// from source or rebuilt from a type).
 func (b *NodeBuilderImpl) reuseName(node *ast.Node) *ast.Node {
 	res := b.reuseNode(node)
-	if res != nil && res.Kind == ast.KindIdentifier && node.AsIdentifier().Text == "new" {
+	if res == nil {
+		return res
+	}
+	if res.Kind == ast.KindIdentifier && node.AsIdentifier().Text == "new" {
 		str := b.f.NewStringLiteral("new", ast.TokenFlagsNone)
 		b.e.SetOriginal(str, res)
 		return b.setTextRange(str, res)
 	}
+	if res.Kind == ast.KindStringLiteral {
+		text := res.AsStringLiteral().Text
+		// Skip normalization for "new" so that reused names like `"new"(): void` on a
+		// method signature are not converted to an identifier (which would become a
+		// construct signature). This mirrors the `isMethodNamedNew` guard in
+		// createPropertyNameNodeForIdentifierOrLiteral.
+		if text != "new" && scanner.IsIdentifierText(text, core.LanguageVariantStandard) {
+			ident := b.newIdentifier(text, nil)
+			b.e.SetOriginal(ident, res)
+			return b.setTextRange(ident, res)
+		}
+	}
 	return res
 }
 

testdata/baselines/reference/compiler/declarationEmitStringNamedPropertyConsistency.js

@@ -0,0 +1,23 @@
+//// [tests/cases/compiler/declarationEmitStringNamedPropertyConsistency.ts] ////
+
+//// [declarationEmitStringNamedPropertyConsistency.ts]
+function createSlice<T>(o: T) {
+    return o
+}
+export const platformSlice = createSlice({
+    "query": {
+        "search" : "",
+        "user": ""
+    },
+});
+
+
+
+
+//// [declarationEmitStringNamedPropertyConsistency.d.ts]
+export declare const platformSlice: {
+    query: {
+        search: string;
+        user: string;
+    };
+};

testdata/baselines/reference/compiler/declarationEmitStringNamedPropertyConsistency.symbols

@@ -0,0 +1,28 @@
+//// [tests/cases/compiler/declarationEmitStringNamedPropertyConsistency.ts] ////
+
+=== declarationEmitStringNamedPropertyConsistency.ts ===
+function createSlice<T>(o: T) {
+>createSlice : Symbol(createSlice, Decl(declarationEmitStringNamedPropertyConsistency.ts, 0, 0))
+>T : Symbol(T, Decl(declarationEmitStringNamedPropertyConsistency.ts, 0, 21))
+>o : Symbol(o, Decl(declarationEmitStringNamedPropertyConsistency.ts, 0, 24))
+>T : Symbol(T, Decl(declarationEmitStringNamedPropertyConsistency.ts, 0, 21))
+
+    return o
+>o : Symbol(o, Decl(declarationEmitStringNamedPropertyConsistency.ts, 0, 24))
+}
+export const platformSlice = createSlice({
+>platformSlice : Symbol(platformSlice, Decl(declarationEmitStringNamedPropertyConsistency.ts, 3, 12))
+>createSlice : Symbol(createSlice, Decl(declarationEmitStringNamedPropertyConsistency.ts, 0, 0))
+
+    "query": {
+>"query" : Symbol("query", Decl(declarationEmitStringNamedPropertyConsistency.ts, 3, 42))
+
+        "search" : "",
+>"search" : Symbol("search", Decl(declarationEmitStringNamedPropertyConsistency.ts, 4, 14))
+
+        "user": ""
+>"user" : Symbol("user", Decl(declarationEmitStringNamedPropertyConsistency.ts, 5, 22))
+
+    },
+});
+

testdata/baselines/reference/compiler/declarationEmitStringNamedPropertyConsistency.types

@@ -0,0 +1,31 @@
+//// [tests/cases/compiler/declarationEmitStringNamedPropertyConsistency.ts] ////
+
+=== declarationEmitStringNamedPropertyConsistency.ts ===
+function createSlice<T>(o: T) {
+>createSlice : <T>(o: T) => T
+>o : T
+
+    return o
+>o : T
+}
+export const platformSlice = createSlice({
+>platformSlice : { query: { search: string; user: string; }; }
+>createSlice({    "query": {        "search" : "",        "user": ""    },}) : { query: { search: string; user: string; }; }
+>createSlice : <T>(o: T) => T
+>{    "query": {        "search" : "",        "user": ""    },} : { query: { search: string; user: string; }; }
+
+    "query": {
+>"query" : { search: string; user: string; }
+>{        "search" : "",        "user": ""    } : { search: string; user: string; }
+
+        "search" : "",
+>"search" : string
+>"" : ""
+
+        "user": ""
+>"user" : string
+>"" : ""
+
+    },
+});
+

testdata/baselines/reference/submodule/compiler/escapedReservedCompilerNamedIdentifier.js

@@ -69,7 +69,7 @@ var b5 = o5["_proto__"];
 //// [escapedReservedCompilerNamedIdentifier.d.ts]
 declare var __proto__: number;
 declare var o: {
-    "__proto__": number;
+    __proto__: number;
 };
 declare var b: number;
 declare var o1: {
@@ -78,7 +78,7 @@ declare var o1: {
 declare var b1: number;
 declare var ___proto__: number;
 declare var o2: {
-    "___proto__": number;
+    ___proto__: number;
 };
 declare var b2: number;
 declare var o3: {
@@ -87,7 +87,7 @@ declare var o3: {
 declare var b3: number;
 declare var _proto__: number;
 declare var o4: {
-    "_proto__": number;
+    _proto__: number;
 };
 declare var b4: number;
 declare var o5: {

testdata/baselines/reference/submodule/conformance/jsDeclarationsPackageJson(target=es2015).types

@@ -2,17 +2,17 @@
 
 === index.js ===
 const j = require("./package.json");
->j : { name: string; version: string; description: string; main: string; bin: { "cli": string; }; engines: { "node": string; }; scripts: { "scriptname": string; }; devDependencies: { "@ns/dep": string; }; dependencies: { "dep": string; }; repository: string; keywords: string[]; author: string; license: string; homepage: string; config: { "o": string[]; }; }
->require("./package.json") : { name: string; version: string; description: string; main: string; bin: { "cli": string; }; engines: { "node": string; }; scripts: { "scriptname": string; }; devDependencies: { "@ns/dep": string; }; dependencies: { "dep": string; }; repository: string; keywords: string[]; author: string; license: string; homepage: string; config: { "o": string[]; }; }
+>j : { name: string; version: string; description: string; main: string; bin: { cli: string; }; engines: { node: string; }; scripts: { scriptname: string; }; devDependencies: { "@ns/dep": string; }; dependencies: { dep: string; }; repository: string; keywords: string[]; author: string; license: string; homepage: string; config: { o: string[]; }; }
+>require("./package.json") : { name: string; version: string; description: string; main: string; bin: { cli: string; }; engines: { node: string; }; scripts: { scriptname: string; }; devDependencies: { "@ns/dep": string; }; dependencies: { dep: string; }; repository: string; keywords: string[]; author: string; license: string; homepage: string; config: { o: string[]; }; }
 >require : any
 >"./package.json" : "./package.json"
 
 module.exports = j;
->module.exports = j : { name: string; version: string; description: string; main: string; bin: { "cli": string; }; engines: { "node": string; }; scripts: { "scriptname": string; }; devDependencies: { "@ns/dep": string; }; dependencies: { "dep": string; }; repository: string; keywords: string[]; author: string; license: string; homepage: string; config: { "o": string[]; }; }
->module.exports : { name: string; version: string; description: string; main: string; bin: { "cli": string; }; engines: { "node": string; }; scripts: { "scriptname": string; }; devDependencies: { "@ns/dep": string; }; dependencies: { "dep": string; }; repository: string; keywords: string[]; author: string; license: string; homepage: string; config: { "o": string[]; }; }
->module : { exports: { name: string; version: string; description: string; main: string; bin: { "cli": string; }; engines: { "node": string; }; scripts: { "scriptname": string; }; devDependencies: { "@ns/dep": string; }; dependencies: { "dep": string; }; repository: string; keywords: string[]; author: string; license: string; homepage: string; config: { "o": string[]; }; }; }
->exports : { name: string; version: string; description: string; main: string; bin: { "cli": string; }; engines: { "node": string; }; scripts: { "scriptname": string; }; devDependencies: { "@ns/dep": string; }; dependencies: { "dep": string; }; repository: string; keywords: string[]; author: string; license: string; homepage: string; config: { "o": string[]; }; }
->j : { name: string; version: string; description: string; main: string; bin: { "cli": string; }; engines: { "node": string; }; scripts: { "scriptname": string; }; devDependencies: { "@ns/dep": string; }; dependencies: { "dep": string; }; repository: string; keywords: string[]; author: string; license: string; homepage: string; config: { "o": string[]; }; }
+>module.exports = j : { name: string; version: string; description: string; main: string; bin: { cli: string; }; engines: { node: string; }; scripts: { scriptname: string; }; devDependencies: { "@ns/dep": string; }; dependencies: { dep: string; }; repository: string; keywords: string[]; author: string; license: string; homepage: string; config: { o: string[]; }; }
+>module.exports : { name: string; version: string; description: string; main: string; bin: { cli: string; }; engines: { node: string; }; scripts: { scriptname: string; }; devDependencies: { "@ns/dep": string; }; dependencies: { dep: string; }; repository: string; keywords: string[]; author: string; license: string; homepage: string; config: { o: string[]; }; }
+>module : { exports: { name: string; version: string; description: string; main: string; bin: { cli: string; }; engines: { node: string; }; scripts: { scriptname: string; }; devDependencies: { "@ns/dep": string; }; dependencies: { dep: string; }; repository: string; keywords: string[]; author: string; license: string; homepage: string; config: { o: string[]; }; }; }
+>exports : { name: string; version: string; description: string; main: string; bin: { cli: string; }; engines: { node: string; }; scripts: { scriptname: string; }; devDependencies: { "@ns/dep": string; }; dependencies: { dep: string; }; repository: string; keywords: string[]; author: string; license: string; homepage: string; config: { o: string[]; }; }
+>j : { name: string; version: string; description: string; main: string; bin: { cli: string; }; engines: { node: string; }; scripts: { scriptname: string; }; devDependencies: { "@ns/dep": string; }; dependencies: { dep: string; }; repository: string; keywords: string[]; author: string; license: string; homepage: string; config: { o: string[]; }; }
 
 === package.json ===
 {

testdata/baselines/reference/submodule/conformance/jsDeclarationsPackageJson(target=es2015).types.diff

@@ -1247,9 +1247,6 @@ compiler/defaultDeclarationEmitShadowedNamedCorrectly.js.diff
 compiler/es5ExportEqualsDts(target=es2015).js.diff
 compiler/declarationEmitNameConflicts.js.diff
 
-## Properties with __proto__-like names now quoted in declaration emit (it's quoted in the originating sourcefile)
-compiler/escapedReservedCompilerNamedIdentifier.js.diff
-
 ## Nested /*elided*/ type annotation comments removed at deeper nesting levels (`/*elided*/` comments are internal artifacts with no semantic meaning)
 ## Declaration emit no longer preserves elided comments in nested class expressions
 compiler/emitClassExpressionInDeclarationFile.js.diff

testdata/baselines/reference/submoduleAccepted/compiler/escapedReservedCompilerNamedIdentifier.js.diff

@@ -0,0 +1,12 @@
+// @declaration: true
+// @emitDeclarationOnly: true
+
+function createSlice<T>(o: T) {
+    return o
+}
+export const platformSlice = createSlice({
+    "query": {
+        "search" : "",
+        "user": ""
+    },
+});