fix: evict deleted browser routes

Drop cached browser routing entries after successful DELETE /browsers/:id responses so stale base URLs are not reused, and cover both the success and failure paths in the routing tests.

Made-with: Cursor

Author: rgarcia

src/lib/browser-routing.ts

@@ -30,6 +30,7 @@ export class BrowserRouteCache {
 const BROWSER_ROUTING_SUBRESOURCES_ENV = 'KERNEL_BROWSER_ROUTING_SUBRESOURCES';
 const DEFAULT_BROWSER_ROUTING_SUBRESOURCES = ['curl'];
 const BROWSER_ROUTE_CACHEABLE_PATH = /^\/(?:v\d+\/)?browsers(?:\/[^/]+)?\/?$/;
+const BROWSER_DELETE_BY_ID_PATH = /^\/(?:v\d+\/)?browsers\/([^/]+)\/?$/;
 
 export function browserRoutingSubresourcesFromEnv(): string[] {
   const raw = readBrowserRoutingSubresourcesEnv();
@@ -69,6 +70,7 @@ export function createRoutingFetch(
     if (shouldSniff) {
       await sniffAndPopulateCache(response, cache);
     }
+    maybeEvictDeletedBrowserRoute(request, response, apiOrigin, cache);
     return response;
   };
 }
@@ -78,6 +80,34 @@ function shouldSniffAndPopulateCache(request: Request, apiOrigin: string): boole
   return url.origin === apiOrigin && BROWSER_ROUTE_CACHEABLE_PATH.test(url.pathname);
 }
 
+function maybeEvictDeletedBrowserRoute(
+  request: Request,
+  response: Response,
+  apiOrigin: string,
+  cache: BrowserRouteCache,
+): void {
+  if (!response.ok || request.method.toUpperCase() !== 'DELETE') {
+    return;
+  }
+
+  const url = new URL(request.url);
+  if (url.origin !== apiOrigin) {
+    return;
+  }
+
+  const match = url.pathname.match(BROWSER_DELETE_BY_ID_PATH);
+  if (!match) {
+    return;
+  }
+
+  const sessionId = decodeURIComponent(match[1] ?? '');
+  if (!sessionId) {
+    return;
+  }
+
+  cache.delete(sessionId);
+}
+
 function browserRouteFromValue(value: unknown): BrowserRoute | undefined {
   if (!value || typeof value !== 'object') {
     return undefined;

tests/lib/browser-routing.test.ts

@@ -233,6 +233,52 @@ describe('browser routing', () => {
     await expect(kernel.browsers.fetch('sess-1', 'https://example.com/again')).rejects.toThrow(/route cache/);
   });
 
+  test('evicts cached route after successful browser delete by id', async () => {
+    const calls: string[] = [];
+    const kernel = new Kernel({
+      apiKey: 'k',
+      baseURL: 'https://api.example/',
+      fetch: async (input) => {
+        const url = normalizeURL(input);
+        calls.push(url);
+        return new Response(null, { status: 204 });
+      },
+    });
+
+    kernel.browserRouteCache.set({
+      sessionId: 'sess-1',
+      baseURL: 'http://browser-session.test/browser/kernel',
+      jwt: 'token-abc',
+    });
+
+    await kernel.browsers.deleteByID('sess-1');
+
+    expect(calls).toEqual(['https://api.example/browsers/sess-1']);
+    expect(kernel.browserRouteCache.get('sess-1')).toBeUndefined();
+  });
+
+  test('keeps cached route when browser delete by id fails', async () => {
+    const kernel = new Kernel({
+      apiKey: 'k',
+      baseURL: 'https://api.example/',
+      maxRetries: 0,
+      fetch: async () => new Response('boom', { status: 500, headers: { 'content-type': 'text/plain' } }),
+    });
+
+    kernel.browserRouteCache.set({
+      sessionId: 'sess-1',
+      baseURL: 'http://browser-session.test/browser/kernel',
+      jwt: 'token-abc',
+    });
+
+    await expect(kernel.browsers.deleteByID('sess-1')).rejects.toThrow();
+    expect(kernel.browserRouteCache.get('sess-1')).toMatchObject({
+      sessionId: 'sess-1',
+      baseURL: 'http://browser-session.test/browser/kernel',
+      jwt: 'token-abc',
+    });
+  });
+
   test('browser.fetch supports HEAD requests', async () => {
     const calls: Array<{ url: string; init: RequestInit | undefined }> = [];
     const kernel = new Kernel({