Stop an infinite loop when using an exported JSDoc function as a type

src/compiler/checker.ts

@@ -11616,9 +11616,16 @@ namespace ts {
                         }
                         isRequireAlias = isCallExpression(expr) && isRequireCall(expr, /*requireStringLiteralLikeArgument*/ true) && !!valueType.symbol;
                     }
-                    const isImportTypeWithQualifier = node.kind === SyntaxKind.ImportType && (node as ImportTypeNode).qualifier;
+
+                    // We need to do an extra hop to find the correct type when type being referred is a class, because
+                    // a class and its type are interwoven in the type, see jsdocImportTypeReferenceToClassAlias for
+                    // an example of it in action
+                    const isImportOfClassTypeWithQualifier = node.kind === SyntaxKind.ImportType
+                        && (node as ImportTypeNode).qualifier
+                        && valueType.symbol.flags & SymbolFlags.Class;
                     // valueType might not have a symbol, eg, {import('./b').STRING_LITERAL}
-                    if (valueType.symbol && (isRequireAlias || isImportTypeWithQualifier)) {
+                    if (valueType.symbol && (isRequireAlias || isImportOfClassTypeWithQualifier)) {
+                        // follow fake alias (commonjs or class value->type)
                         typeType = getTypeReferenceType(node, valueType.symbol);
                     }
                 }

tests/baselines/reference/jsDocImplicitTypeOfForValueImport.symbols

@@ -0,0 +1,15 @@
+=== tests/cases/compiler/lib/index.js ===
+// 36830
+//
+
+/** @type {import('../folder/index').zzz} */
+export function xxx() {
+>xxx : Symbol(xxx, Decl(index.js, 0, 0))
+
+  return null;
+}
+
+=== tests/cases/compiler/folder/index.d.ts ===
+export function zzz(): string;
+>zzz : Symbol(zzz, Decl(index.d.ts, 0, 0))
+

tests/baselines/reference/jsdocImportTypeReferenceToClassAlias.symbols

@@ -21,8 +21,6 @@ function demo(c) {
 >c : Symbol(c, Decl(test.js, 2, 14))
 
     c.s
->c.s : Symbol(C.s, Decl(mod1.js, 0, 9))
 >c : Symbol(c, Decl(test.js, 2, 14))
->s : Symbol(C.s, Decl(mod1.js, 0, 9))
 }
 

tests/baselines/reference/jsdocImportTypeReferenceToClassAlias.types

@@ -19,11 +19,11 @@ module.exports.C = C
 /** @param {X} c */
 function demo(c) {
 >demo : (c: X) => void
->c : C
+>c : typeof C
 
     c.s
->c.s : () => void
->c : C
->s : () => void
+>c.s : any
+>c : typeof C
+>s : any
 }
 

tests/cases/compiler/jsDocImplicitTypeOfForValueImport.ts

@@ -0,0 +1,14 @@
+// 36830
+//
+// @allowJs: true
+// @noEmit: true
+// @checkJs: true
+
+// @filename: lib/index.js
+/** @type {import('../folder/index').zzz} */
+export function xxx() {
+  return null;
+}
+
+// @filename: folder/index.d.ts
+export function zzz(): string;

tests/cases/fourslash/fourslash.ts

@@ -28,7 +28,7 @@
 
 //---------------------------------------
 // For API editors:
-// When editting this file, and only while editing this file, enable the reference comments
+// When editing this file, and only while editing this file, enable the reference comments
 // and comment out the declarations in this section to get proper type information.
 // Undo these changes before compiling/committing/editing any other fourslash tests.
 // The test suite will likely crash if you try 'jake runtests' with reference comments enabled.