don't skip jsdoc type assertions

src/compiler/checker.ts

@@ -45645,7 +45645,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         const functionFlags = getFunctionFlags(container);
         const unwrappedReturnType = unwrapReturnType(returnType, functionFlags) ?? returnType;
         if (expr) {
-            const unwrappedExpr = skipParentheses(expr);
+            const unwrappedExpr = skipParentheses(expr, /*excludeJSDocTypeAssertions*/ true);
             if (isConditionalExpression(unwrappedExpr)) {
                 return checkConditionalReturnExpression(container, returnType, node, unwrappedExpr);
             }

tests/baselines/reference/dependentReturnType7.symbols

@@ -0,0 +1,34 @@
+//// [tests/cases/compiler/dependentReturnType7.ts] ////
+
+=== file.js ===
+/** @type {Map<string, string>} */
+const sources = new Map();
+>sources : Symbol(sources, Decl(file.js, 1, 5))
+>Map : Symbol(Map, Decl(lib.es2015.collection.d.ts, --, --), Decl(lib.es2015.collection.d.ts, --, --), Decl(lib.es2015.iterable.d.ts, --, --), Decl(lib.es2015.symbol.wellknown.d.ts, --, --))
+
+/**
+
+ * @param {string=} type the type of source that should be generated
+ * @returns {String}
+ */
+function source(type = "javascript") {
+>source : Symbol(source, Decl(file.js, 1, 26))
+>type : Symbol(type, Decl(file.js, 7, 16))
+
+    return /** @type {String} */ (
+        type
+>type : Symbol(type, Decl(file.js, 7, 16))
+
+            ? sources.get(type)
+>sources.get : Symbol(Map.get, Decl(lib.es2015.collection.d.ts, --, --))
+>sources : Symbol(sources, Decl(file.js, 1, 5))
+>get : Symbol(Map.get, Decl(lib.es2015.collection.d.ts, --, --))
+>type : Symbol(type, Decl(file.js, 7, 16))
+
+            : sources.get("some other thing")
+>sources.get : Symbol(Map.get, Decl(lib.es2015.collection.d.ts, --, --))
+>sources : Symbol(sources, Decl(file.js, 1, 5))
+>get : Symbol(Map.get, Decl(lib.es2015.collection.d.ts, --, --))
+
+    );
+}

tests/baselines/reference/dependentReturnType7.types

@@ -0,0 +1,65 @@
+//// [tests/cases/compiler/dependentReturnType7.ts] ////
+
+=== Performance Stats ===
+Type Count: 1,000
+Instantiation count: 2,500
+
+=== file.js ===
+/** @type {Map<string, string>} */
+const sources = new Map();
+>sources : Map<string, string>
+>        : ^^^^^^^^^^^^^^^^^^^
+>new Map() : Map<any, any>
+>          : ^^^^^^^^^^^^^
+>Map : MapConstructor
+>    : ^^^^^^^^^^^^^^
+
+/**
+
+ * @param {string=} type the type of source that should be generated
+ * @returns {String}
+ */
+function source(type = "javascript") {
+>source : (type?: string | undefined) => string
+>       : ^    ^^^         ^^^^^^^^^^^^^^^^^^^^
+>type : string | undefined
+>     : ^^^^^^^^^^^^^^^^^^
+>"javascript" : "javascript"
+>             : ^^^^^^^^^^^^
+
+    return /** @type {String} */ (
+>(        type            ? sources.get(type)            : sources.get("some other thing")    ) : string
+>                                                                                               : ^^^^^^
+
+        type
+>type            ? sources.get(type)            : sources.get("some other thing") : string | undefined
+>                                                                                 : ^^^^^^^^^^^^^^^^^^
+>type : string
+>     : ^^^^^^
+
+            ? sources.get(type)
+>sources.get(type) : string | undefined
+>                  : ^^^^^^^^^^^^^^^^^^
+>sources.get : (key: string) => string | undefined
+>            : ^   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+>sources : Map<string, string>
+>        : ^^^^^^^^^^^^^^^^^^^
+>get : (key: string) => string | undefined
+>    : ^   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+>type : string
+>     : ^^^^^^
+
+            : sources.get("some other thing")
+>sources.get("some other thing") : string | undefined
+>                                : ^^^^^^^^^^^^^^^^^^
+>sources.get : (key: string) => string | undefined
+>            : ^   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+>sources : Map<string, string>
+>        : ^^^^^^^^^^^^^^^^^^^
+>get : (key: string) => string | undefined
+>    : ^   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+>"some other thing" : "some other thing"
+>                   : ^^^^^^^^^^^^^^^^^^
+
+    );
+}

tests/cases/compiler/dependentReturnType7.ts

@@ -0,0 +1,20 @@
+// @strict: true
+// @noEmit: true
+// @target: esnext
+// @checkJs: true
+// @filename: file.js
+
+/** @type {Map<string, string>} */
+const sources = new Map();
+/**
+
+ * @param {string=} type the type of source that should be generated
+ * @returns {String}
+ */
+function source(type = "javascript") {
+    return /** @type {String} */ (
+        type
+            ? sources.get(type)
+            : sources.get("some other thing")
+    );
+}