fix(proxy): preserve HTTP env proxy request target

[magus]

Summary

Fixes HTTP proxy handling in httpRequest() when proxy settings come from environment variables.

When http_proxy/HTTP_PROXY is set and NO_PROXY is empty, connectOverCDP("http://localhost:<port>") performs CDP discovery through the proxy by requesting /json/version/.

In the broken path, Playwright mutates the proxy URL pathname

parsedProxyURL.pathname = url.toString();

Because URL.pathname normalizes the value as a path, this serializes the request target as

GET /http://localhost:<port>/json/version/ HTTP/1.1

For HTTP proxying, the request target must remain absolute-form

GET http://localhost:<port>/json/version/ HTTP/1.1

This patch stores the original target URL in options.path instead, preserving the correct proxy request target while still sending the request to the proxy server.

Related context

• [Bug]:playwright.connectOverCDP can't connect to the browser via a proxy #35206
• feat: support proxy in connect/connectOverCDP #35389

Testing

npx playwright test \
--config=tests/library/playwright.config.ts \
--project=chromium-library \
tests/library/chromium/connect-over-cdp.spec.ts \
-g "should use env proxy with connectOverCDP discovery request" \
--reporter=line

Before the fix, the regression test fails with

- "http://localhost:<port>/json/version/"
+ "/http://localhost:<port>/json/version/"

After the fix, the test passes

---

fixes #40394

[magus]

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[Skn0tt]

Hi Noah, thanks for the PR. The change looks good, what a subtle bug :/

Could you shorten the test a little? This should be good, I think:

test('should use env proxy with connectOverCDP discovery request', async ({ browserType, server, proxyServer, mode }) => {
  test.info().annotations.push({ type: 'issue', description: 'https://github.com/microsoft/playwright/issues/40394' });
  test.skip(mode !== 'default'); // Out of process transport does not allow us to set env vars dynamically.
  proxyServer.forwardTo(server.PORT);

  const oldValue = process.env.HTTP_PROXY;
  try {
    process.env.HTTP_PROXY = proxyServer.URL;
    await browserType.connectOverCDP(server.PREFIX).catch(() => {});
    expect(proxyServer.requestUrls).toEqual([`${server.PREFIX}/json/version/`]);
  } finally {
    process.env.HTTP_PROXY = oldValue;
  }
});

The HTTPS_PROXY env var doesn't matter in this context.

[magus]

Hi Noah, thanks for the PR. The change looks good, what a subtle bug :/

Could you shorten the test a little? This should be good, I think:

test('should use env proxy with connectOverCDP discovery request', async ({ browserType, server, proxyServer, mode }) => {
  test.info().annotations.push({ type: 'issue', description: 'https://github.com/microsoft/playwright/issues/40394' });
  test.skip(mode !== 'default'); // Out of process transport does not allow us to set env vars dynamically.
  proxyServer.forwardTo(server.PORT);

  const oldValue = process.env.HTTP_PROXY;
  try {
    process.env.HTTP_PROXY = proxyServer.URL;
    await browserType.connectOverCDP(server.PREFIX).catch(() => {});
    expect(proxyServer.requestUrls).toEqual([`${server.PREFIX}/json/version/`]);
  } finally {
    process.env.HTTP_PROXY = oldValue;
  }
});

The HTTPS_PROXY env var doesn't matter in this context.

Done, thanks for simplifying!

[github-actions]

Test results for "MCP"

2 failed
❌ [webkit] › mcp/dashboard.spec.ts:185 › should start dashboard and annotate when no dashboard is running @mcp-macos-latest
❌ [webkit] › mcp/dashboard.spec.ts:207 › should enter annotate mode on fresh dashboard.tsx mount with -s --annotate @mcp-macos-latest

6675 passed, 928 skipped

---

Merge workflow run.

[github-actions]

Test results for "tests 1"

10 flaky

⚠️ [chromium-library] › library/chromium/connect-over-cdp.spec.ts:449 › should be able to connect via localhost `@ubuntu-22.04-chromium-tip-of-tree`
⚠️ [chromium-library] › library/chromium/connect-over-cdp.spec.ts:449 › should be able to connect via localhost `@chromium-ubuntu-22.04-arm-node20`
⚠️ [chromium-library] › library/video.spec.ts:719 › screencast › should work with video+trace `@chromium-ubuntu-22.04-arm-node20`
⚠️ [chromium-library] › library/chromium/connect-over-cdp.spec.ts:449 › should be able to connect via localhost `@chromium-ubuntu-22.04-node24`
⚠️ [chromium-library] › library/popup.spec.ts:261 › should not throw when click closes popup `@chromium-ubuntu-22.04-node24`
⚠️ [chromium-library] › library/chromium/connect-over-cdp.spec.ts:449 › should be able to connect via localhost `@chromium-ubuntu-22.04-node20`
⚠️ [chromium-library] › library/video.spec.ts:476 › screencast › should capture static page in persistent context @smoke `@chromium-ubuntu-22.04-node20`
⚠️ [chromium-library] › library/chromium/connect-over-cdp.spec.ts:449 › should be able to connect via localhost `@chromium-ubuntu-22.04-node22`
⚠️ [firefox-library] › library/inspector/cli-codegen-1.spec.ts:1080 › cli codegen › should not throw csp directive violation errors `@firefox-ubuntu-22.04-node20`
⚠️ [playwright-test] › ui-mode-test-output.spec.ts:118 › should collapse repeated console messages for test `@ubuntu-latest-node22`

41452 passed, 847 skipped

---

Merge workflow run.