fix(fetch): support proxy.bypass (#22914)

Fixes #21916

packages/playwright-core/src/server/fetch.ts

@@ -150,11 +150,16 @@ export abstract class APIRequestContext extends SdkObject {
         setHeader(headers, name, value);
     }
 
+    const requestUrl = new URL(params.url, defaults.baseURL);
+    if (params.params) {
+      for (const { name, value } of params.params)
+        requestUrl.searchParams.set(name, value);
+    }
+
     const method = params.method?.toUpperCase() || 'GET';
     const proxy = defaults.proxy;
     let agent;
-    if (proxy && proxy.server !== 'per-context') {
-      // TODO: support bypass proxy
+    if (proxy && proxy.server !== 'per-context' && !shouldBypassProxy(requestUrl, proxy.bypass)) {
       const proxyOpts = url.parse(proxy.server);
       if (proxyOpts.protocol?.startsWith('socks')) {
         agent = new SocksProxyAgent({
@@ -184,12 +189,6 @@ export abstract class APIRequestContext extends SdkObject {
     if (params.ignoreHTTPSErrors || defaults.ignoreHTTPSErrors)
       options.rejectUnauthorized = false;
 
-    const requestUrl = new URL(params.url, defaults.baseURL);
-    if (params.params) {
-      for (const { name, value } of params.params)
-        requestUrl.searchParams.set(name, value);
-    }
-
     const postData = serializePostData(params, headers);
     if (postData)
       setHeader(headers, 'content-length', String(postData.byteLength));
@@ -706,3 +705,16 @@ function getHeader(headers: HeadersObject, name: string) {
 function removeHeader(headers: { [name: string]: string }, name: string) {
   delete headers[name];
 }
+
+function shouldBypassProxy(url: URL, bypass?: string): boolean {
+  if (!bypass)
+    return false;
+  const domains = bypass.split(',').map(s => {
+    s = s.trim();
+    if (!s.startsWith('.'))
+      s = '.' + s;
+    return s;
+  });
+  const domain = '.' + url.hostname;
+  return domains.some(d => domain.endsWith(d));
+}

tests/library/browsercontext-fetch.spec.ts

@@ -370,6 +370,58 @@ it('should pass proxy credentials', async ({ browserType, server, proxyServer })
   await browser.close();
 });
 
+it(`should support proxy.bypass`, async ({ browser, browserType, browserName, contextOptions, server, proxyServer }) => {
+  server.setRoute('/target.html', async (req, res) => {
+    res.end('Served by the proxy');
+  });
+  // FYI: using long and weird domain names to avoid ATT DNS hijacking
+  // that resolves everything to some weird search results page.
+  //
+  // @see https://gist.github.com/CollinChaffin/24f6c9652efb3d6d5ef2f5502720ef00
+  proxyServer.forwardTo(server.PORT);
+  const context = await browser.newContext({
+    ...contextOptions,
+    proxy: { server: `localhost:${proxyServer.PORT}`, bypass: `1.non.existent.domain.for.the.test, 2.non.existent.domain.for.the.test, .another.test` }
+  });
+
+  {
+    const res = await context.request.get(server.CROSS_PROCESS_PREFIX + '/target.html');
+    expect(await res.text()).toContain('Served by the proxy');
+    expect(proxyServer.connectHosts).toContain(new URL(server.CROSS_PROCESS_PREFIX).host);
+    proxyServer.connectHosts = [];
+  }
+
+  {
+    const res = await context.request.get('http://0.non.existent.domain.for.the.test/target.html');
+    expect(await res.text()).toContain('Served by the proxy');
+    proxyServer.connectHosts = [];
+  }
+
+  {
+    const error = await context.request.get('http://1.non.existent.domain.for.the.test/target.html').catch(e => e);
+    expect(error.message).toBeTruthy();
+    expect(proxyServer.connectHosts).toEqual([]);
+  }
+
+  {
+    const error = await context.request.get('http://2.non.existent.domain.for.the.test/target.html').catch(e => e);
+    expect(error.message).toBeTruthy();
+    expect(proxyServer.connectHosts).toEqual([]);
+  }
+
+  {
+    const error = await context.request.get('http://foo.is.the.another.test/target.html').catch(e => e);
+    expect(error.message).toBeTruthy();
+    expect(proxyServer.connectHosts).toEqual([]);
+  }
+
+  {
+    const res = await context.request.get('http://3.non.existent.domain.for.the.test/target.html');
+    expect(await res.text()).toContain('Served by the proxy');
+  }
+});
+
+
 it('should work with http credentials', async ({ context, server }) => {
   server.setAuth('/empty.html', 'user', 'pass');