fix(52061): Constructor parameters exported as type included in emitted metadata (#52138)

Author: a-tarasyuk

src/compiler/checker.ts

@@ -45812,7 +45812,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         }
         const valueSymbol = resolveEntityName(typeName, SymbolFlags.Value, /*ignoreErrors*/ true, /*dontResolveAlias*/ true, location);
         const resolvedSymbol = valueSymbol && valueSymbol.flags & SymbolFlags.Alias ? resolveAlias(valueSymbol) : valueSymbol;
-        isTypeOnly ||= !!valueSymbol?.declarations?.every(isTypeOnlyImportOrExportDeclaration);
+        isTypeOnly ||= !!(valueSymbol && getTypeOnlyAliasDeclaration(valueSymbol, SymbolFlags.Value));
 
         // Resolve the symbol as a type so that we can provide a more useful hint for the type serializer.
         const typeSymbol = resolveEntityName(typeName, SymbolFlags.Type, /*ignoreErrors*/ true, /*dontResolveAlias*/ false, location);

tests/baselines/reference/decoratorMetadataTypeOnlyExport.js

@@ -0,0 +1,47 @@
+//// [tests/cases/compiler/decoratorMetadataTypeOnlyExport.ts] ////
+
+//// [a.ts]
+class Foo {}
+export type { Foo };
+
+//// [b.ts]
+import { Foo } from "./a";
+
+const Decorator: ClassDecorator = () => undefined;
+
+@Decorator
+class Bar {
+    constructor(par: Foo) {}
+}
+
+
+//// [a.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+var Foo = /** @class */ (function () {
+    function Foo() {
+    }
+    return Foo;
+}());
+//// [b.js]
+"use strict";
+var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
+    var c = arguments.length, r = c < 3 ? target : desc === null ? desc = Object.getOwnPropertyDescriptor(target, key) : desc, d;
+    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") r = Reflect.decorate(decorators, target, key, desc);
+    else for (var i = decorators.length - 1; i >= 0; i--) if (d = decorators[i]) r = (c < 3 ? d(r) : c > 3 ? d(target, key, r) : d(target, key)) || r;
+    return c > 3 && r && Object.defineProperty(target, key, r), r;
+};
+var __metadata = (this && this.__metadata) || function (k, v) {
+    if (typeof Reflect === "object" && typeof Reflect.metadata === "function") return Reflect.metadata(k, v);
+};
+Object.defineProperty(exports, "__esModule", { value: true });
+var Decorator = function () { return undefined; };
+var Bar = /** @class */ (function () {
+    function Bar(par) {
+    }
+    Bar = __decorate([
+        Decorator,
+        __metadata("design:paramtypes", [Function])
+    ], Bar);
+    return Bar;
+}());

tests/baselines/reference/decoratorMetadataTypeOnlyExport.symbols

@@ -0,0 +1,27 @@
+=== tests/cases/compiler/a.ts ===
+class Foo {}
+>Foo : Symbol(Foo, Decl(a.ts, 0, 0))
+
+export type { Foo };
+>Foo : Symbol(Foo, Decl(a.ts, 1, 13))
+
+=== tests/cases/compiler/b.ts ===
+import { Foo } from "./a";
+>Foo : Symbol(Foo, Decl(b.ts, 0, 8))
+
+const Decorator: ClassDecorator = () => undefined;
+>Decorator : Symbol(Decorator, Decl(b.ts, 2, 5))
+>ClassDecorator : Symbol(ClassDecorator, Decl(lib.decorators.legacy.d.ts, --, --))
+>undefined : Symbol(undefined)
+
+@Decorator
+>Decorator : Symbol(Decorator, Decl(b.ts, 2, 5))
+
+class Bar {
+>Bar : Symbol(Bar, Decl(b.ts, 2, 50))
+
+    constructor(par: Foo) {}
+>par : Symbol(par, Decl(b.ts, 6, 16))
+>Foo : Symbol(Foo, Decl(b.ts, 0, 8))
+}
+

tests/baselines/reference/decoratorMetadataTypeOnlyExport.types

@@ -0,0 +1,26 @@
+=== tests/cases/compiler/a.ts ===
+class Foo {}
+>Foo : Foo
+
+export type { Foo };
+>Foo : Foo
+
+=== tests/cases/compiler/b.ts ===
+import { Foo } from "./a";
+>Foo : typeof Foo
+
+const Decorator: ClassDecorator = () => undefined;
+>Decorator : ClassDecorator
+>() => undefined : () => any
+>undefined : undefined
+
+@Decorator
+>Decorator : ClassDecorator
+
+class Bar {
+>Bar : Bar
+
+    constructor(par: Foo) {}
+>par : Foo
+}
+

tests/cases/compiler/decoratorMetadataTypeOnlyExport.ts

@@ -0,0 +1,16 @@
+// @experimentalDecorators: true
+// @emitDecoratorMetadata: true
+
+// @filename: ./a.ts
+class Foo {}
+export type { Foo };
+
+// @filename: ./b.ts
+import { Foo } from "./a";
+
+const Decorator: ClassDecorator = () => undefined;
+
+@Decorator
+class Bar {
+    constructor(par: Foo) {}
+}