feat(fs-router) add console errors for duplicated paths (#2259)

packages/ts/file-router/src/vite-plugin/createRoutesFromMeta.ts

@@ -76,11 +76,19 @@ export default function createRoutesFromMeta(views: RouteMeta, { code: codeFile
       ([statement]) => statement as ts.ImportDeclaration,
     ),
   ];
+  const errors: string[] = [];
   let id = 0;
 
   const routes = transformTreeSync<RouteMeta, CallExpression>(
     views,
-    (view) => view.children.values(),
+    (view) => {
+      const paths = view.children.map((c) => c.path);
+      const uniquePaths = new Set(paths);
+      paths
+        .filter((p) => !uniquePaths.delete(p))
+        .forEach((p) => errors.push(`console.error("Two views share the same path: ${p}");`));
+      return view.children.values();
+    },
     ({ file, layout, path }, children) => {
       const currentId = id;
       id += 1;
@@ -101,6 +109,8 @@ export default function createRoutesFromMeta(views: RouteMeta, { code: codeFile
   const routeDeclaration = template(
     `import a from 'IMPORTS';
 
+${errors.join('\n')}
+
 const routes = ROUTE;
 
 export default routes;

packages/ts/file-router/test/vite-plugin/createRoutesFromMeta.spec.ts

@@ -41,5 +41,16 @@ const routes = createRoute("", [createRoute("nameToReplace", Page0), createRoute
 export default routes;
 `);
     });
+
+    it('should add console.error calls for duplicated paths', () => {
+      const metaWithDuplicatedPaths = createTestingRouteMeta(new URL('./views/', dir));
+      metaWithDuplicatedPaths.children.push({
+        path: 'profile',
+        file: new URL('profile/$index.tsx', dir),
+        children: [],
+      });
+      const generated = createRoutesFromMeta(metaWithDuplicatedPaths, runtimeUrls);
+      expect(generated).to.contain('console.error("Two views share the same path: profile");');
+    });
   });
 });