[WIP] Reference missing with declare module

src/services/findAllReferences.ts

@@ -1687,13 +1687,24 @@ export namespace Core {
                     scope = next;
                 }
             }
-        }
-
-        // If symbol.parent, this means we are in an export of an external module. (Otherwise we would have returned `undefined` above.)
-        // For an export of a module, we may be in a declaration file, and it may be accessed elsewhere. E.g.:
-        //     declare module "a" { export type T = number; }
-        //     declare module "b" { import { T } from "a"; export const x: T; }
-        // So we must search the whole source file. (Because we will mark the source file as seen, we we won't return to it when searching for imports.)
+        }
+
+        // If symbol.parent, this means we are in an export of an external module. (Otherwise we would have returned `undefined` above.)
+        // For an export of a module, we may be in a declaration file, and it may be accessed elsewhere. E.g.:
+        //     declare module "a" { export type T = number; }
+        //     declare module "b" { import { T } from "a"; export const x: T; }
+        // So we must search the whole source file. (Because we will mark the source file as seen, we we won't return to it when searching for imports.)
+        // However, for declare modules, the exports are globally accessible and can be used from any file, so we should do a global search.
+        if (exposedByParent && parent && isExternalModuleSymbol(parent)) {
+            // Check if this is a declare module by examining the declarations
+            const isInDeclareModule = parent.declarations?.some(decl => 
+                isModuleDeclaration(decl) && (decl.flags & NodeFlags.GlobalAugmentation) === 0
+            );
+            if (isInDeclareModule) {
+                // For declare modules, do a global search since their exports can be accessed from anywhere
+                return undefined;
+            }
+        }
         return exposedByParent ? scope!.getSourceFile() : scope; // TODO: GH#18217
     }
 

tests/cases/fourslash/findAllRefsWithDeclareModule.ts

@@ -0,0 +1,15 @@
+/// <reference path="fourslash.ts" />
+
+////declare module '@bug/api/index' {
+////  export * from "@bug/api/miscFunctions";
+////}
+////declare module '@bug/api/miscFunctions' {
+////  export function /*1*/myFunction(testParam: string): Promise<any>;
+////}
+////
+////declare namespace bug.v0 {const api: typeof import('@bug/api/index')}
+////
+//////// test.ts
+////bug.v0.api./*2*/myFunction('test')
+
+verify.baselineFindAllReferences('1', '2');

tests/cases/fourslash/findAllRefsWithDeclareModuleDuplicate.ts

@@ -0,0 +1,23 @@
+/// <reference path="fourslash.ts" />
+
+////declare module '@bug/api/index' {
+////  export * from "@bug/api/miscFunctions";
+////}
+////declare module '@bug/api/miscFunctions' {
+////  export function /*1*/myFunction(testParam: string): Promise<any>;
+////}
+////
+////declare namespace bug.v0 {const api: typeof import('@bug/api/index')}
+
+////declare module '@bug/api/index' {
+////  export * from "@bug/api/miscFunctions";
+////}
+////declare module '@bug/api/miscFunctions' {
+////  export function /*2*/myFunction(testParam: string): Promise<any>;
+////}
+////
+////declare namespace bug.v0 {const api: typeof import('@bug/api/index')}
+
+////bug.v0.api./*3*/myFunction('test')
+
+verify.baselineFindAllReferences('1', '2', '3');