1943315 - "Save Response As" action in devtools:network tab saves truncated json

Status: NEW

(DevTools :: Netmonitor, defect, P3)

Description

[Akiyamka]

Attachment: Screenshot from 2025-01-23 13-52-43.png

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:132.0) Gecko/20100101 Firefox/132.0

Steps to reproduce:

1. Open DevTools on Network tab
2. Wait for request with ~4MB JSON response body
3. Right-click this response
4. Click "Save Response As" option in dropdown menu
5. Select save location
6. Wait for download to complete (no progress indicator, waited ~30 seconds for 3-second response)

Actual results:

Saved file is truncated to match devtools.netmonitor.responseBodyLimit setting size
(1 MiB by default)

Expected results:

devtools.netmonitor.responseBodyLimit should only affect UI display
"Save Response As" should save complete response

Comment 1

[BugBot [:suhaib / :marco]]

The Bugbug bot thinks this bug should belong to the 'DevTools::Netmonitor' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[Julian Descottes [:jdescottes]]

The only way we can save the whole response is to do another request at this point because we don't store response bodies which are over the limit.

One option is to show a notification after downloading the file to propose to do another request + download.

Comment 3

[Julian Descottes [:jdescottes]]

As mentioned in https://phabricator.services.mozilla.com/D219220, this will also impact the feature to set overrides from the network monitor, as only the truncated response would be copied over to the override.

Comment 4

[Jake Archibald [:jakea]]

If making this work is hard, can we disable the menu item in cases where the response would be incomplete?