fix: resolve route file outside of app dir relative to app dir

Author: frodi-karlsson

.changeset/red-pugs-itch.md

@@ -0,0 +1,5 @@
+---
+"@react-router/fs-routes": patch
+---
+
+Resolve route file outside of app directory relative to app directory

packages/react-router-fs-routes/__tests__/flatRoutes-test.ts

@@ -912,4 +912,14 @@ describe("flatRoutes", () => {
       );
     });
   });
+
+  test("should include a valid file for a route outside of the app directory", () => {
+    const routesDir = path.join("test", "root", "routes");
+    const routeFile = path.join(routesDir, "route.tsx");
+
+    const manifest = flatRoutesUniversal(APP_DIR, [routeFile]);
+    const routeInfo = manifest[path.relative(APP_DIR, routesDir)];
+    expect(routeInfo).toBeDefined();
+    expect(routeInfo.file).toBe(path.relative(APP_DIR, routeFile));
+  });
 });

packages/react-router-fs-routes/flatRoutes.ts

@@ -174,7 +174,7 @@ export function flatRoutesUniversal(
     let pathname = createRoutePath(segments, raw, index);
 
     routeManifest[routeId] = {
-      file: file.slice(appDirectory.length + 1),
+      file: path.relative(appDirectory, file),
       id: routeId,
       path: pathname,
     };