playwright: [BUG] [Chromium/WebKit] Request object does not contain postData for file/blob

Context:

System:

OS: Windows 10 10.0.19043

Binaries:

Node: 12.13.1 - C:\Program Files\nodejs\node.EXE
Yarn: 1.19.1 - ~\AppData\Roaming\npm\yarn.CMD
npm: 6.14.2 - C:\Program Files\nodejs\npm.CMD

Languages:

Bash: 4.4.20 - C:\WINDOWS\system32\bash.EXE

npmPackages:

playwright: ^1.10.0 => 1.10.0 / tip-of-tree

Code Snippet

Help us help you! Put down a short code snippet that illustrates your bug and that we can run and debug locally. For example:

const playwright = require('.');

(async () => {
  const browser = await playwright.webkit.launch();
  const page = await browser.newPage();

  await page.goto('http://example.com');

  const requestPromise = page.waitForRequest(() => true);
  const [request] = await Promise.all([
    page.waitForRequest("**/*"),
    page.evaluate(() => {
      var file = new File(['file-contents'], 'filename.txt');

      fetch('/data', {
        method: 'POST',
        headers: {
          'content-type': 'application/octet-stream'
        },
        body: file
      });
    })
  ])
  console.info('request.method()', request.method());
  console.info('request.url()', request.url());
  console.info('request.headers()', request.headers());
  console.info('request.postData()', request.postData());
})();

Describe the bug

the request.postData() contains null in Chromium and WebKit. In Firefox it’s filled.

About this issue

Original URL
State: open
Created 3 years ago
Reactions: 28
Comments: 27 (7 by maintainers)

Links to this issue

python - How to retrieve form data from Playwright Request object? - Stack Overflow

Commits related to this issue

update to the latest Playwright & workaround postData===null https://github.com/microsoft/playwright/issues/6479#issuecomment-1193105330 — committed to mitmplay/mitm-play by wharsojo 2 years ago
First prototype of using external proxy We noticed that some requests were failing when routed through our replay proxy, but succeed on a normal chrome instance. Further investigation found that ther... — committed to piercefreeman/popdown by piercefreeman 2 years ago
Send web vitals to Vercel analytics in app (#40669) Sends web vitals to Vercel analytics. My plan for the test was to assert the data sent by the client but there's a bug where it's always null when... — committed to vercel/next.js by deleted user 2 years ago

Most upvoted comments

chromium bug is closed as Wontfix, https://bugs.chromium.org/p/chromium/issues/detail?id=1058404. Is there any way to route multipart/form-data requests and get not null postData? (using chrome/chromium)

shinijimmy3 on Jan 24, 2024

I’m facing this issue, but not on all my playwright project.

I’ve 2 projects with e2e, both use chromium, and i mock request to get postDataJson() On the first project is working fine, i get the value that i need. On the second project i get undifined, like the bug you describe here.

My workaround for the second project is to use firefox and it’s working fine.

But i don’t understand why is working on the first and not on the second project… The depenedencies are the same, the mock request to get postDataJson is the same.

I’m surprise this issue have 2 years old !

Horsty80 on Jun 6, 2023

The link above seems to indicate this is a problem in Chromium, not Playwright. However, if you follow the discussion details it does not seem like the Chromium folks “are on it”.

humbienri on Dec 6, 2021

Same for the JS version with Chromium and contentType application/json on PUT and POST. Works with Firefox for the same requests.

sch0057k on Oct 20, 2021

It seems that they are finally working on it: https://bugs.chromium.org/p/chromium/issues/detail?id=1019710#c23 https://chromium.googlesource.com/chromium/src/+/2f4d40dfc9fbd14e0f105551fce94f428566a796

MikeFear on Jan 11, 2023

A bit of a hack for ky users, you can use a hook to prevent ky from cloning responses :

    hooks : {
      beforeRequest: [
        (request: Request) => {
          request.clone = () => request
          return request
        }
      ],
    },

cameronbraid on Sep 17, 2022

There must be some difference between your projects. From what I understood, problem is when you or libraries are using request.clone(). In that case, postData is empty and it’s a Chromium bug, not playwright. But Chromium has that bug since 2020, and who knows if they’ll ever fix it, so maybe PlayWright could introduce some workaround.

paradox37 on Jun 6, 2023

Facing the same issue. The postData is always null but in network tab its clear that the data exists. In my case it is normal json payload post request. I am using the java binding at the moment.

karamfilovs on Oct 6, 2021

Thanks for filing! Short of using a proxy, I don’t think there are any good workarounds at this time. These look like bugs in chromium and our webkit. It might take some time to fix, but I’m on the case!

JoelEinbinder on May 10, 2021