[whatwg/fetch] Include end time in opaque responses (PR #1953)

Resource timing always includes `responseEnd`, even when TAO is omitted.

Closes #1945

(See [WHATWG Working Mode: Changes](https://whatwg.org/working-mode#changes) for more details.)


<!--
    This comment and the below content is programmatically generated.
    You may add a comma-separated list of anchors you'd like a
    direct link to below (e.g. #idl-serializers, #idl-sequence):

    Don't remove this comment or modify anything below this line.
    If you don't want a preview generated for this pull request,
    just replace the whole of this comment's content by "no preview"
    and remove what's below.
-->
***

### :boom: Error: 422 Unprocessable Entity :boom: ###

[PR Preview](https://github.com/tobie/pr-preview#pr-preview) failed to build. _(Last tried on Aug 24, 2026, 10:21 AM UTC)_.

<details>
<summary>More</summary>


PR Preview relies on a number of web services to run. There seems to be an issue with the following one:

:rotating_light: [Spec Generator](https://www.w3.org/publications/spec-generator/) - Spec Generator is the web service used to build bikeshed/ReSpec specs

:link: [Related URL](https://www.w3.org/publications/spec-generator/?type=bikeshed-spec&output=html&url=https%3A%2F%2Fraw.githubusercontent.com%2Fwhatwg%2Ffetch%2F569993faa84f2c8b66f76cbf04477fb8138e160d%2Ffetch.bs&force=1&md-status=LS-PR&md-Text-Macro=PR-NUMBER%201953)

**Error output:**

```json
[
    {
        "lineNum": "407:31",
        "messageType": "fatal",
        "text": "Expected whitespace between attributes. (for\"fetc...)"
    },
    {
        "lineNum": "407:31",
        "messageType": "fatal",
        "text": "While trying to parse a <a> start tag, ran into some unparseable stuff (\"fetch)."
    },
    {
        "lineNum": "407:59",
        "messageType": "fatal",
        "text": "Saw an end tag </a>, but there's no open element corresponding to it.\nOpen tags: <div> at 400:1, <p> at 401:1"
    },
    {
        "lineNum": null,
        "messageType": "failure",
        "text": "Did not generate, due to errors exceeding the allowed error level."
    }
]
```

_This seems to be an issue with the [Spec Generator](https://www.w3.org/publications/spec-generator/) service. PR Preview doesn't manage this service and so has no control over it. If you've identified an issue with it, you can [report the issue to the maintainers of Spec Generator](https://github.com/w3c/spec-generator/issues/new) directly. Please be courteous. Thank you!_

_If you don't have enough information above to solve the error by yourself or if the issue doesn't seem related to Spec Generator, you can [file an issue with PR Preview](https://github.com/tobie/pr-preview/issues/new?title=Unidentified%20Error&body=See%20whatwg/fetch%231953.)._

</details>

You can view, comment on, or merge this pull request online at:

  https://github.com/whatwg/fetch/pull/1953

-- Commit Summary --

  * Include end time in opaque responses

-- File Changes --

    M fetch.bs (3)

-- Patch Links --

https://github.com/whatwg/fetch/pull/1953.patch
https://github.com/whatwg/fetch/pull/1953.diff

-- 
Reply to this email directly or view it on GitHub:
https://github.com/whatwg/fetch/pull/1953
You are receiving this because you are subscribed to this thread.

Message ID: <whatwg/fetch/pull/1953@github.com>