Fix 18224 (microsoft#18259)

weswigham · web-flow · commit 73eff819b589 · 2017-09-06T14:44:29.000-07:00
* Probably fix 18224

* Corrected test
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -18017,7 +18017,7 @@ namespace ts {
 
         function checkParenthesizedExpression(node: ParenthesizedExpression, checkMode?: CheckMode): Type {
             if (isInJavaScriptFile(node) && node.jsDoc) {
-                const typecasts = flatMap(node.jsDoc, doc => filter(doc.tags, tag => tag.kind === SyntaxKind.JSDocTypeTag));
+                const typecasts = flatMap(node.jsDoc, doc => filter(doc.tags, tag => tag.kind === SyntaxKind.JSDocTypeTag && !!(tag as JSDocTypeTag).typeExpression && !!(tag as JSDocTypeTag).typeExpression.type));
                 if (typecasts && typecasts.length) {
                     // We should have already issued an error if there were multiple type jsdocs
                     const cast = typecasts[0] as JSDocTypeTag;
diff --git a/tests/baselines/reference/jsdocTypecastNoTypeNoCrash.js b/tests/baselines/reference/jsdocTypecastNoTypeNoCrash.js
@@ -0,0 +1,8 @@
+//// [index.js]
+function Foo() {}
+const a = /* @type string */(Foo);
+
+
+//// [index.js]
+function Foo() { }
+var a = (Foo);
diff --git a/tests/baselines/reference/jsdocTypecastNoTypeNoCrash.symbols b/tests/baselines/reference/jsdocTypecastNoTypeNoCrash.symbols
@@ -0,0 +1,8 @@
+=== tests/cases/compiler/index.js ===
+function Foo() {}
+>Foo : Symbol(Foo, Decl(index.js, 0, 0))
+
+const a = /* @type string */(Foo);
+>a : Symbol(a, Decl(index.js, 1, 5))
+>Foo : Symbol(Foo, Decl(index.js, 0, 0))
+
diff --git a/tests/baselines/reference/jsdocTypecastNoTypeNoCrash.types b/tests/baselines/reference/jsdocTypecastNoTypeNoCrash.types
@@ -0,0 +1,9 @@
+=== tests/cases/compiler/index.js ===
+function Foo() {}
+>Foo : () => void
+
+const a = /* @type string */(Foo);
+>a : () => void
+>(Foo) : () => void
+>Foo : () => void
+
diff --git a/tests/cases/compiler/jsdocTypecastNoTypeNoCrash.ts b/tests/cases/compiler/jsdocTypecastNoTypeNoCrash.ts
@@ -0,0 +1,5 @@
+// @allowJS: true
+// @outDir: ./out
+// @filename: index.js
+function Foo() {}
+const a = /* @type string */(Foo);
