[BUG] route.fulfill ignores some response headers

[BeejeeDS]

System info

• Playwright Version: [v1.40.1]
• Operating System: [Windows 10]
• Browser: [Chromium]
• Other info:

Source code

page.route('https://random.com/api/documents/*', async route => {
    await route.fulfill({
            contentType: 'text/csv',
            headers: {
                'Content-Disposition': 'inline; filename=test.csv'
            },
            body: 'This is a test'
        }
    );
});

Expected

I expect the content-type and content-disposition headers to be present in the response.

Actual

The response doesn't contain the content-disposition header, only content-type is present.

Playwright config

export default defineConfig({
    ...nxE2EPreset(__filename, { testDir: './e2e' }),
    retries: 3,
    workers: process.env.CI ? 1 : 2,
    fullyParallel: true,
    reporter: [['playwright-trx-reporter', { outputFile: 'e2e-xxx-results.trx' }]],
    timeout: 5 * 60 * 1000,
    use: {
        baseURL,
        trace: 'on-first-retry',
        screenshot: 'only-on-failure',
        video: 'on' //retain-on-failure --> na de POC
    },
    projects: [
        { name: 'setup', testMatch: /.*\.setup\.ts/ },
        {
            name: 'chromium',
            use: {
                ...devices['Desktop Chrome']
            },
            dependencies: ['setup']
        }
        // {
        //     name: 'firefox',
        //     use: {
        //         ...devices['Desktop Firefox'],
        //     },
        //     dependencies: ['setup'],
        // },
        // {
        //     name: 'webkit',
        //     use: {
        //         ...devices['Desktop Safari'],
        //     },
        //     dependencies: ['setup'],
        // },
    ],
    /* Run your local dev server before starting the tests */
    webServer: [
        {
            command: 'npm run start',
            url: baseURL,
            reuseExistingServer: !process.env.CI,
            timeout: 300000
        }
    ]
});

[mxschmitt]

I tried the following which works for me, what am I doing different?

import { chromium } from 'playwright';

(async () => {
  const browser = await chromium.launch({
    headless: false,
  });
  const context = await browser.newContext();
  const page = await context.newPage();

  await page.goto('https://example.com');
  await page.route('**/foo.pdf', async route => {
    await route.fulfill({
      contentType: 'text/csv',
      headers: {
        'Content-Disposition': 'inline; filename=test.csv'
      },
      body: 'This is a test'
    }
    );
  });
  console.log('Received download: ' + JSON.stringify(await page.evaluate(() => fetch('https://example.com/foo.pdf').then(r => ([...r.headers.entries()])))));

  // Teardown
  await context.close();
  await browser.close();
})();

[BeejeeDS]

@mxschmitt I've added your example to my project but the result stays the same, there are 2 headers (content-length and content-type) but no content-disposition header.

I've added my playwright.config to my original message.

This is the test I've created based on your code sample:

    test('Mxschmitt test.', async () => {
        const browser = await chromium.launch({
            headless: false,
        });
        const context = await browser.newContext();
        const page = await context.newPage();

        await page.route('**/foo.pdf', async route => {
            await route.fulfill({
                    contentType: 'text/csv',
                    headers: {
                        'Content-Disposition': 'inline; filename=test.csv'
                    },
                    body: 'This is a test'
                }
            );
        });

        // @ts-ignore
        console.log('Received download: ' + JSON.stringify(await page.evaluate(() => fetch('https://example.com/foo.pdf').then(r => ([...r.headers.entries()])))));
        // Returns Received download: [["content-length","14"],["content-type","text/csv"]]

        // Teardown
        await context.close();
        await browser.close();
    });`

[mxschmitt]

If you do await page.goto('https://example.com'); before the page.route, it works as intended. Would that work for you? Seems like something what Chromium is internally doing.

[mxschmitt]

Closing as per above. Please re-file for further bug reports / feature requests.