Fxied declaration emit for JS files when module.exports is assigned a non-alias value and when it has extra type members (#56243)

Author: Andarist

src/compiler/checker.ts

@@ -8758,7 +8758,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
             });
             let addingDeclare = !bundled;
             const exportEquals = symbolTable.get(InternalSymbolName.ExportEquals);
-            if (exportEquals && symbolTable.size > 1 && exportEquals.flags & SymbolFlags.Alias) {
+            if (exportEquals && symbolTable.size > 1 && exportEquals.flags & (SymbolFlags.Alias | SymbolFlags.Module)) {
                 symbolTable = createSymbolTable();
                 // Remove extraneous elements from root symbol table (they'll be mixed back in when the target of the `export=` is looked up)
                 symbolTable.set(InternalSymbolName.ExportEquals, exportEquals);
@@ -9291,8 +9291,18 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
             }
 
             function getNamespaceMembersForSerialization(symbol: Symbol) {
-                const exports = getExportsOfSymbol(symbol);
-                return !exports ? [] : filter(arrayFrom(exports.values()), m => isNamespaceMember(m) && isIdentifierText(m.escapedName as string, ScriptTarget.ESNext));
+                let exports = arrayFrom(getExportsOfSymbol(symbol).values());
+                const merged = getMergedSymbol(symbol);
+                if (merged !== symbol) {
+                    const membersSet = new Set(exports);
+                    for (const exported of getExportsOfSymbol(merged).values()) {
+                        if (!(getSymbolFlags(resolveSymbol(exported)) & SymbolFlags.Value)) {
+                            membersSet.add(exported);
+                        }
+                    }
+                    exports = arrayFrom(membersSet);
+                }
+                return filter(exports, m => isNamespaceMember(m) && isIdentifierText(m.escapedName as string, ScriptTarget.ESNext));
             }
 
             function isTypeOnlyNamespace(symbol: Symbol) {

tests/baselines/reference/jsDeclarationEmitExportAssignedFunctionWithExtraTypedefsMembers.js

@@ -0,0 +1,35 @@
+//// [tests/cases/compiler/jsDeclarationEmitExportAssignedFunctionWithExtraTypedefsMembers.ts] ////
+
+//// [index.js]
+/**
+ * @typedef Options
+ * @property {string} opt
+ */
+
+/**
+ * @param {Options} options
+ */
+module.exports = function loader(options) {}
+
+
+//// [index.js]
+"use strict";
+/**
+ * @typedef Options
+ * @property {string} opt
+ */
+/**
+ * @param {Options} options
+ */
+module.exports = function loader(options) { };
+
+
+//// [index.d.ts]
+declare namespace _exports {
+    export { Options };
+}
+declare function _exports(options: Options): void;
+export = _exports;
+type Options = {
+    opt: string;
+};

tests/baselines/reference/jsDeclarationEmitExportAssignedFunctionWithExtraTypedefsMembers.symbols

@@ -0,0 +1,18 @@
+//// [tests/cases/compiler/jsDeclarationEmitExportAssignedFunctionWithExtraTypedefsMembers.ts] ////
+
+=== index.js ===
+/**
+ * @typedef Options
+ * @property {string} opt
+ */
+
+/**
+ * @param {Options} options
+ */
+module.exports = function loader(options) {}
+>module.exports : Symbol(module.exports, Decl(index.js, 0, 0))
+>module : Symbol(export=, Decl(index.js, 0, 0))
+>exports : Symbol(export=, Decl(index.js, 0, 0))
+>loader : Symbol(loader, Decl(index.js, 8, 16))
+>options : Symbol(options, Decl(index.js, 8, 33))
+

tests/baselines/reference/jsDeclarationEmitExportAssignedFunctionWithExtraTypedefsMembers.types

@@ -0,0 +1,20 @@
+//// [tests/cases/compiler/jsDeclarationEmitExportAssignedFunctionWithExtraTypedefsMembers.ts] ////
+
+=== index.js ===
+/**
+ * @typedef Options
+ * @property {string} opt
+ */
+
+/**
+ * @param {Options} options
+ */
+module.exports = function loader(options) {}
+>module.exports = function loader(options) {} : (options: Options) => void
+>module.exports : (options: Options) => void
+>module : { exports: (options: Options) => void; }
+>exports : (options: Options) => void
+>function loader(options) {} : (options: Options) => void
+>loader : (options: Options) => void
+>options : Options
+

tests/cases/compiler/jsDeclarationEmitExportAssignedFunctionWithExtraTypedefsMembers.ts

@@ -0,0 +1,16 @@
+// @strict: true
+// @checkJs: true
+// @declaration: true
+// @outDir: out
+
+// @filename: index.js
+
+/**
+ * @typedef Options
+ * @property {string} opt
+ */
+
+/**
+ * @param {Options} options
+ */
+module.exports = function loader(options) {}