From 557a34e897dbabdcf567cfea343c9443112fdaea Mon Sep 17 00:00:00 2001
From: Wesley Wigham <wwigham@gmail.com>
Date: Thu, 19 Apr 2018 10:28:30 -0700
Subject: [PATCH] Visit typedef type expressions so they contribute to
 referenced-ness (#23525)

---
 src/compiler/checker.ts                       |  6 ++++
 .../checkJsTypeDefNoUnusedLocalMarked.symbols | 27 ++++++++++++++++
 .../checkJsTypeDefNoUnusedLocalMarked.types   | 32 +++++++++++++++++++
 .../checkJsTypeDefNoUnusedLocalMarked.ts      | 20 ++++++++++++
 4 files changed, 85 insertions(+)
 create mode 100644 tests/baselines/reference/checkJsTypeDefNoUnusedLocalMarked.symbols
 create mode 100644 tests/baselines/reference/checkJsTypeDefNoUnusedLocalMarked.types
 create mode 100644 tests/cases/compiler/checkJsTypeDefNoUnusedLocalMarked.ts

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index f497ba82e4..62cff0b1ce 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -21865,6 +21865,11 @@ namespace ts {
                 // If the node had `@property` tags, `typeExpression` would have been set to the first property tag.
                 error(node.name, Diagnostics.JSDoc_typedef_tag_should_either_have_a_type_annotation_or_be_followed_by_property_or_member_tags);
             }
+
+            if (node.name) {
+                checkTypeNameIsReserved(node.name, Diagnostics.Type_alias_name_cannot_be_0);
+            }
+            checkSourceElement(node.typeExpression);
         }
 
         function checkJSDocParameterTag(node: JSDocParameterTag) {
@@ -24765,6 +24770,7 @@ namespace ts {
                 case SyntaxKind.JSDocNullableType:
                 case SyntaxKind.JSDocAllType:
                 case SyntaxKind.JSDocUnknownType:
+                case SyntaxKind.JSDocTypeLiteral:
                     checkJSDocTypeIsInJsFile(node);
                     forEachChild(node, checkSourceElement);
                     return;
diff --git a/tests/baselines/reference/checkJsTypeDefNoUnusedLocalMarked.symbols b/tests/baselines/reference/checkJsTypeDefNoUnusedLocalMarked.symbols
new file mode 100644
index 0000000000..6826881b83
--- /dev/null
+++ b/tests/baselines/reference/checkJsTypeDefNoUnusedLocalMarked.symbols
@@ -0,0 +1,27 @@
+=== tests/cases/compiler/file.ts ===
+class Foo {
+>Foo : Symbol(Foo, Decl(file.ts, 0, 0))
+
+    x: number;
+>x : Symbol(Foo.x, Decl(file.ts, 0, 11))
+}
+
+declare global {
+>global : Symbol(global, Decl(file.ts, 2, 1))
+
+    var module: any; // Just here to remove unrelated error from test
+>module : Symbol(module, Decl(file.ts, 5, 7))
+}
+
+export = Foo;
+>Foo : Symbol(Foo, Decl(file.ts, 0, 0))
+
+=== tests/cases/compiler/something.js ===
+/** @typedef {typeof import("./file")} Foo */
+
+/** @typedef {(foo: Foo) => string} FooFun */
+
+module.exports = /** @type {FooFun} */(void 0);
+>module : Symbol(export=, Decl(something.js, 0, 0))
+>exports : Symbol(export=, Decl(something.js, 0, 0))
+
diff --git a/tests/baselines/reference/checkJsTypeDefNoUnusedLocalMarked.types b/tests/baselines/reference/checkJsTypeDefNoUnusedLocalMarked.types
new file mode 100644
index 0000000000..1428cce142
--- /dev/null
+++ b/tests/baselines/reference/checkJsTypeDefNoUnusedLocalMarked.types
@@ -0,0 +1,32 @@
+=== tests/cases/compiler/file.ts ===
+class Foo {
+>Foo : Foo
+
+    x: number;
+>x : number
+}
+
+declare global {
+>global : typeof global
+
+    var module: any; // Just here to remove unrelated error from test
+>module : any
+}
+
+export = Foo;
+>Foo : Foo
+
+=== tests/cases/compiler/something.js ===
+/** @typedef {typeof import("./file")} Foo */
+
+/** @typedef {(foo: Foo) => string} FooFun */
+
+module.exports = /** @type {FooFun} */(void 0);
+>module.exports = /** @type {FooFun} */(void 0) : (foo: typeof Foo) => string
+>module.exports : any
+>module : any
+>exports : any
+>(void 0) : (foo: typeof Foo) => string
+>void 0 : undefined
+>0 : 0
+
diff --git a/tests/cases/compiler/checkJsTypeDefNoUnusedLocalMarked.ts b/tests/cases/compiler/checkJsTypeDefNoUnusedLocalMarked.ts
new file mode 100644
index 0000000000..559e0ee725
--- /dev/null
+++ b/tests/cases/compiler/checkJsTypeDefNoUnusedLocalMarked.ts
@@ -0,0 +1,20 @@
+// @allowJs: true
+// @checkJs: true
+// @noEmit: true
+// @noUnusedLocals: true
+// @filename: file.ts
+class Foo {
+    x: number;
+}
+
+declare global {
+    var module: any; // Just here to remove unrelated error from test
+}
+
+export = Foo;
+// @filename: something.js
+/** @typedef {typeof import("./file")} Foo */
+
+/** @typedef {(foo: Foo) => string} FooFun */
+
+module.exports = /** @type {FooFun} */(void 0);
\ No newline at end of file