Upgrade QuotaExceededError to a DOMException derived interface by domenic · Pull Request #1465 · whatwg/webidl

domenic · 2025-01-27T07:45:17Z

The proposal

The web platform benefits from having a type of exception that tells you about when you exceed quotas. In some cases, it can be helpful to tell you what the quota was, and by how much you exceeded it. webmachinelearning/writing-assistance-apis#5 gives one specific use case.

The web platform already has an exception type for telling you when you exceed quotas: it is DOMException, with the specific name property set to "QuotaExceededError". However, this does not allow carrying additional information.

This PR proposes removing "QuotaExceededError" from the list of built-in DOMException names, and instead creates a class named QuotaExceededError that derives from DOMException and has the additional optional properties quota and requested. We propose that all instances of specs that throw "QuotaExceededError" DOMExceptions get upgraded to instead throw QuotaExceededErrors. For now, such specs would leave the quota and requested properties at their default value of null, but they could eventually upgrade to include that data, if it's useful for their use case (and isn't, e.g., a privacy leak).

Alternative considered

The most promising alternative considered was to add a new class that sits alongside "QuotaExceededError" DOMException. Maybe it would be called QuotaExceededErrorWithDetails, or maybe we could even call it QuotaExceededError despite the confusion this might cause. But it would be undesirable for the web platform to have two types of quota-exceeded errors, with different APIs giving different ones. So, because we believe the compat implications are not too bad, we're interested in trying this upgrade route instead.

There are other possibilities, such as using custom bindings to sometimes add properties to base "QuotaExceededError" DOMException instances, or trying to add some generic additional information capability to the base DOMException class. However, these don't fit well with how classes work on the web platform, with getters providing predefined data on a per-class basis. They would be hacky to maintain both in specs and implementations, and a bit surprising for web developers as well due to the mismatch with other web platform classes.

Compat considerations

The following coding patterns will work unchanged if we upgrade all "QuotaExceededError" DOMExceptions to QuotaExceedErrors:

ex instanceof DOMException
ex.name === "QuotaExceededError"
DOMException.QUOTA_EXCEEDED_ERR === 22
(new DOMException("message", "QuotaExceededError")).name === "QuotaExceededError"
(new DOMException("message", "QuotaExceededError")).code === DOMException.QUOTA_EXCEEDED_ERR
ex.code === DOMException.QUOTA_EXCEEDED_ERR
ex.code === 22

The following coding patterns will start giving different answers:

ex.constructor === DOMException
ex.constructor.name === "DOMException"

We believe that these coding patterns are quite rare. See, for example, these GitHub search results, which show only a couple instances of .constructor testing (repeated in a few forks).

The tests like ex instanceof DOMException and ex.name === "QuotaExceededError" are much more common, and commonly seen in documentation. (See, e.g., these GitHub search results.)

Furthermore, since quotas being exceeded is a relatively rare thing to happen on the web, we suspect that the combination of these rare coding patterns with this rare type of DOMException means the impacted number of page views will be extremely small.

We could add some use counters for these coding patterns, but they would be sloppy. In particular, we could count cases where .constructor is accessed, but not cases where it is compared to DOMException, so any count would be inflated by generic constructor-accessing code, and not really tell us much about the problematic coding pattern.

Nevertheless, there's definitely some compat risk. So the best rollout plan here would probably be for Chromium to cautiously take the lead and report back if it sticks, before necessarily merging changes to all the relevant specs.

Proposed commit message:

Upgrade QuotaExceededError to a DOMException derived interface

Closes #1463.

Labeling "do not merge yet" as we should also create PRs for these specs, and we probably don't want to merge until we see if this sticks in Chromium:

The following cases did not need PRs because they were using inaccurate spec text (just QuotaExceededError, instead of "QuotaExceededError" DOMException), which has now become correct by accident:

At least two implementers are interested (and none opposed):
- Chromium
- Gecko is supportive if Chromium finds the compat risk to be reasonable, per 2025-02-06 WHATNOT meeting
Tests are written and can be reviewed and commented upon at:
- Update QuotaExceededError expectations web-platform-tests/wpt#53645
Implementation bugs are filed:
- Chromium: https://issues.chromium.org/issues/406162261
- Gecko: https://bugzilla.mozilla.org/show_bug.cgi?id=1976159
- WebKit: https://bugs.webkit.org/show_bug.cgi?id=295570
- Deno: Update QuotaExceededError handling denoland/deno#30028
- Node.js: Update QuotaExceededError handling nodejs/node#58987
- webidl2.js: N/A
- widlparser: N/A
MDN issue is filed: Upgrade QuotaExceededError to a DOMException derived interface #1465
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(See WHATWG Working Mode: Changes for more details.)

Preview | Diff

Closes #1463.

Closes #5. Closes #31 by obsoleting it. Depends on whatwg/webidl#1465.

Closes #5. Obsoletes #31. Depends on whatwg/webidl#1465.

This change introduces a new QuotaExceededError class to update the existing QuotaExceededError so services can return `quota` and `requested` properties as needed. Implemented behind RuntimeEnabledFlag `QuotaExceededErrorUpdate`. Changes to update services throwing QuotaExceededError to use the new class will be made in following changes (except for IDB which triggered failures with this change). Proposal: whatwg/webidl#1465 Chromestatus: https://chromestatus.com/feature/6194847180128256 Bug: 406162261 Change-Id: I68e91e15724e64c0995365ee63d4abe627fe06d3 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6516473 Reviewed-by: Domenic Denicola <domenic@chromium.org> Commit-Queue: Ayu Ishii <ayui@chromium.org> Reviewed-by: Joey Arhar <jarhar@chromium.org> Reviewed-by: Joe Mason <joenotcharles@google.com> Cr-Commit-Position: refs/heads/main@{#1460403}

This change introduces a new QuotaExceededError class to update the existing QuotaExceededError so services can return `quota` and `requested` properties as needed. Implemented behind RuntimeEnabledFlag `QuotaExceededErrorUpdate`. Changes to update services throwing QuotaExceededError to use the new class will be made in following changes (except for IDB which triggered failures with this change). Proposal: whatwg/webidl#1465 Chromestatus: https://chromestatus.com/feature/6194847180128256 Bug: 406162261 Change-Id: I68e91e15724e64c0995365ee63d4abe627fe06d3 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6516473 Reviewed-by: Domenic Denicola <domenic@chromium.org> Commit-Queue: Ayu Ishii <ayui@chromium.org> Reviewed-by: Joey Arhar <jarhar@chromium.org> Reviewed-by: Joe Mason <joenotcharles@google.com> Cr-Commit-Position: refs/heads/main@{#1460403} Co-authored-by: Ayu Ishii <ayui@chromium.org>

This change updates services that use QuotaExceededError to use the new DOMException derived QuotaExceededError class when the flag is enabled. I've not been allowed to update external wpts until the webidl spec has been updated[0][1], so this change only updates tests for Chrome only wpts, and otherwise updates expectations for the external ones. External wpts will be updated when the webidl spec is merged and I am allowed to update the external wpts (as seen in chained CL). [0] Spec PR: whatwg/webidl#1465 [1] Discussion: web-platform-tests/wpt#52571 (comment) Bug: 406162261 Change-Id: Ie45d6095a3e4c21e21a35d2519d268580b8bc36b Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6538066 Commit-Queue: Ayu Ishii <ayui@chromium.org> Reviewed-by: Daseul Lee <dslee@chromium.org> Cr-Commit-Position: refs/heads/main@{#1463139}

…tion derived interface, Automatic update from web-platform-tests QuotaExceededError: Update to a DOMException derived interface (#52556) This change introduces a new QuotaExceededError class to update the existing QuotaExceededError so services can return `quota` and `requested` properties as needed. Implemented behind RuntimeEnabledFlag `QuotaExceededErrorUpdate`. Changes to update services throwing QuotaExceededError to use the new class will be made in following changes (except for IDB which triggered failures with this change). Proposal: whatwg/webidl#1465 Chromestatus: https://chromestatus.com/feature/6194847180128256 Bug: 406162261 Change-Id: I68e91e15724e64c0995365ee63d4abe627fe06d3 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6516473 Reviewed-by: Domenic Denicola <domenic@chromium.org> Commit-Queue: Ayu Ishii <ayui@chromium.org> Reviewed-by: Joey Arhar <jarhar@chromium.org> Reviewed-by: Joe Mason <joenotcharles@google.com> Cr-Commit-Position: refs/heads/main@{#1460403} Co-authored-by: Ayu Ishii <ayui@chromium.org> -- wpt-commits: 16a71c4282b0379f639051c0a3f98f3fcdaa2149 wpt-pr: 52556 Differential Revision: https://phabricator.services.mozilla.com/D250632

This info will be used for QuotaExceededError.requested and QuotaExceededError.quota in a follow-up CL. Spec: whatwg/webidl#1465 Bug: 416303646, 406162261 Change-Id: Id1d414722d2f53de0a566e8b453acdd97f501714 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6568411 Reviewed-by: Mike Wasserman <msw@chromium.org> Commit-Queue: Daseul Lee <dslee@chromium.org> Reviewed-by: Emily Stark <estark@chromium.org> Reviewed-by: Ayu Ishii <ayui@chromium.org> Cr-Commit-Position: refs/heads/main@{#1466096}

…tion derived interface, Automatic update from web-platform-tests QuotaExceededError: Update to a DOMException derived interface (#52556) This change introduces a new QuotaExceededError class to update the existing QuotaExceededError so services can return `quota` and `requested` properties as needed. Implemented behind RuntimeEnabledFlag `QuotaExceededErrorUpdate`. Changes to update services throwing QuotaExceededError to use the new class will be made in following changes (except for IDB which triggered failures with this change). Proposal: whatwg/webidl#1465 Chromestatus: https://chromestatus.com/feature/6194847180128256 Bug: 406162261 Change-Id: I68e91e15724e64c0995365ee63d4abe627fe06d3 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6516473 Reviewed-by: Domenic Denicola <domenicchromium.org> Commit-Queue: Ayu Ishii <ayuichromium.org> Reviewed-by: Joey Arhar <jarharchromium.org> Reviewed-by: Joe Mason <joenotcharlesgoogle.com> Cr-Commit-Position: refs/heads/main{#1460403} Co-authored-by: Ayu Ishii <ayuichromium.org> -- wpt-commits: 16a71c4282b0379f639051c0a3f98f3fcdaa2149 wpt-pr: 52556 Differential Revision: https://phabricator.services.mozilla.com/D250632 UltraBlame original commit: 869cbd71034aec8dfdce6d5342adbfc5d8dbf8e6

…a=testonly Automatic update from web-platform-tests Update QuotaExceededError expectations (#53645) See whatwg/webidl#1465. -- wpt-commits: 1d2c5fb36a6e477c8f915bde7eca027be6abe792 wpt-pr: 53645 UltraBlame original commit: 272d71b3fbc93813a5879430d9f769e4f0eac25c

Reverts just the code value change from crrev.com/c/6516473 Matches resolution in whatwg/webidl#1465 Tests updated in web-platform-tests/wpt#53645 Bug: 406162261 Fixed: 434432288 Change-Id: I2fe06c29c1773fdbec5765a18d5c59a0aa2235f8 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6814000 Commit-Queue: Daniel Cheng <dcheng@chromium.org> Reviewed-by: Daniel Cheng <dcheng@chromium.org> Auto-Submit: Mike Wasserman <msw@chromium.org> Cr-Commit-Position: refs/heads/main@{#1496718}

QuotaExceededError is graduating from being a DOMException name into a new error class, in whatwg/webidl#1465. Update creation sites to reflect this. For now, the quota and requested properties are left at their default (null). Future work could include setting them in an informative fashion.

…spec Original change's description: > QuotaExceededError: Restore legacy exception code 22 to match spec > > Reverts just the code value change from crrev.com/c/6516473 > Matches resolution in whatwg/webidl#1465 > Tests updated in web-platform-tests/wpt#53645 > > Bug: 406162261 > Fixed: 434432288 > Change-Id: I2fe06c29c1773fdbec5765a18d5c59a0aa2235f8 > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6814000 > Commit-Queue: Daniel Cheng <dcheng@chromium.org> > Reviewed-by: Daniel Cheng <dcheng@chromium.org> > Auto-Submit: Mike Wasserman <msw@chromium.org> > Cr-Commit-Position: refs/heads/main@{#1496718} Bug: 436562744,406162261,434432288 Change-Id: I2fe06c29c1773fdbec5765a18d5c59a0aa2235f8 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6818806 Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com> Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com> Auto-Submit: Chrome Cherry Picker <chrome-cherry-picker@chops-service-accounts.iam.gserviceaccount.com> Cr-Commit-Position: refs/branch-heads/7339@{#22} Cr-Branched-From: 27be8b7-refs/heads/main@{#1496484}

See whatwg/webidl#1465.

QuotaExceededError is graduating from being a DOMException name into a new error class, in whatwg/webidl#1465. Update creation sites to reflect this. For now, the quota and requested properties are left at their default (null). Future work could include setting them in an informative fashion.

Once whatwg/webidl#1465 is merged, we can reference Web IDL directly, instead of the pull request preview.

QuotaExceededError is graduating from being a DOMException name into a new error class, in whatwg/webidl#1465. Update creation sites to reflect this. For now, the quota and requested properties are left at their default (null). Future work could include setting them in an informative fashion.

Implements Web IDL spec change (whatwg/webidl#1465) to upgrade QuotaExceededError from a DOMException name to a proper subclass. Changes: - Remove QuotaExceededError from DOMException names table - Create QuotaExceededError class extending DOMException - Add quota and requested properties (default to null) - Update error registration to use new QuotaExceededError class - Add comprehensive tests for QuotaExceededError subclass Fixes denoland#30028

Per whatwg/webidl#1465, QuotaExceededError is no longer a specific DOMException name but will be upgraded to a DOMException subclass. This commit removes QuotaExceededError from the nameToCodeMapping so that new DOMException('msg', 'QuotaExceededError').code returns 0 instead of 22. Fixes denoland#30028

Removes the unused QUOTA_EXCEEDED_ERR constant from DOMException to align with the WebIDL spec change (whatwg/webidl#1465) that makes QuotaExceededError a proper subclass of DOMException rather than just a DOMException name. The constant was defined but never used in the nameToCodeMapping table, making it dead code. QuotaExceededError is now properly implemented as a separate class in 02_quota_exceeded_error.js with code 22, while new DOMException('msg', 'QuotaExceededError') correctly returns code 0. Fixes denoland#30028

… table Per whatwg/webidl#1465, QuotaExceededError has been updated from a legacy DOMException name to a proper DOMException subclass. As the minimal change, this removes QuotaExceededError from the error names table so that `new DOMException('msg', 'QuotaExceededError').code` returns 0 instead of 22, aligning with the updated spec. Fixes denoland#30028

Implements the WebIDL spec change (whatwg/webidl#1465) that upgrades QuotaExceededError from a DOMException error name to a proper derived class extending DOMException with optional `quota` and `requested` properties. Changes: - Remove "QuotaExceededError" from the DOMException names table so `new DOMException("msg", "QuotaExceededError").code === 0` - Add QuotaExceededError class extending DOMException with code 22, and optional `quota`/`requested` properties - Expose QuotaExceededError on the global scope - Update error builder to use QuotaExceededError for Rust-thrown errors - Add TypeScript definitions for QuotaExceededError - Add unit tests Closes denoland#30028 Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

truongminhdien8330-web · 2026-03-22T20:49:50Z

Upgrade QuotaExceededError to a DOMException derived interface

5e1d7e8

Closes #1463.

domenic added the do not merge yet Pull request must not be merged per rationale in comment label Jan 27, 2025

This was referenced Jan 27, 2025

Bikeshedding help needed for generic over-limit error #1463

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Add too many tokens errors and token-counting APIs webmachinelearning/writing-assistance-apis#31

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domenic added the agenda+ To be discussed at a triage meeting label Feb 6, 2025

domenic mentioned this pull request Feb 6, 2025

Upcoming WHATNOT meeting on 2025-02-06 whatwg/html#10972

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past removed the agenda+ To be discussed at a triage meeting label Feb 7, 2025

domenic mentioned this pull request Feb 26, 2025

Ways of telling by how much a too-large input is too large webmachinelearning/writing-assistance-apis#5

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Export the properties people will need

a4a4fe4

domenic added a commit to webmachinelearning/writing-assistance-apis that referenced this pull request Mar 4, 2025

Add quota exceeded error details and input usage APIs

e00023b

Closes #5. Closes #31 by obsoleting it. Depends on whatwg/webidl#1465.

This was referenced Mar 4, 2025

Add quota exceeded error details and input usage APIs webmachinelearning/writing-assistance-apis#43

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Allow doubles for ProgressEvent's loaded and total whatwg/xhr#394

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domenic added a commit to webmachinelearning/writing-assistance-apis that referenced this pull request Mar 5, 2025

Add quota exceeded error details and input usage APIs

1a9abdb

Closes #5. Closes #31 by obsoleting it. Depends on whatwg/webidl#1465.

This was referenced Mar 5, 2025

Update QuotaExceededError to a DOMException derived interface WebKit/standards-positions#468

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Update QuotaExceededError to a DOMException derived interface w3ctag/design-reviews#1065

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domenic added a commit to webmachinelearning/writing-assistance-apis that referenced this pull request Mar 7, 2025

Add quota exceeded error details and input usage APIs

3abf4de

Closes #5. Obsoletes #31. Depends on whatwg/webidl#1465.

ayuishii mentioned this pull request May 6, 2025

Updating QuotaExceededError to a DOMException derived interface mozilla/standards-positions#1223

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chromium-wpt-export-bot mentioned this pull request May 14, 2025

QuotaExceededError: Update to a DOMException derived interface web-platform-tests/wpt#52556

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WeizhongX mentioned this pull request May 15, 2025

Revert "QuotaExceededError: Update to a DOMException derived interface" web-platform-tests/wpt#52571

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domenic mentioned this pull request May 21, 2025

Remove UA styles for h1 in article, aside, nav, section whatwg/html#11102

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jdm mentioned this pull request Aug 6, 2025

QuotaExceededError should be a new WebIDL interface servo/servo#38489

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foolip pushed a commit to web-platform-tests/wpt that referenced this pull request Aug 13, 2025

Update QuotaExceededError expectations (#53645)

19457a3

See whatwg/webidl#1465.

Elchi3 mentioned this pull request Aug 19, 2025

Chrome 138 adds QuotaExceededError interface mdn/browser-compat-data#27613

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domenic added a commit to webmachinelearning/writing-assistance-apis that referenced this pull request Sep 13, 2025

Update QuotaExceededError references

0a057cd

Once whatwg/webidl#1465 is merged, we can reference Web IDL directly, instead of the pull request preview.

domenic added a commit to webmachinelearning/writing-assistance-apis that referenced this pull request Sep 13, 2025

Update QuotaExceededError references

d759046

Once whatwg/webidl#1465 is merged, we can reference Web IDL directly, instead of the pull request preview.

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nt1m mentioned this pull request Nov 17, 2025

Resync resources from WPT Upstream WebKit/WebKit#54061

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imposter29 mentioned this pull request Nov 25, 2025

feat(web): update QuotaExceededError to spec denoland/deno#31400

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Bitshifter-9 mentioned this pull request Nov 28, 2025

feat: upgrade QuotaExceededError to DOMException subclassfeat: upgrade QuotaExceededError to DOMException subclass denoland/deno#31440

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VISHNU7KASIREDDY mentioned this pull request Nov 30, 2025

fix: remove QuotaExceededError from DOMException error names tablefix: remove QuotaExceededError from DOMException error names table denoland/deno#31466

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jdm mentioned this pull request Jan 4, 2026

QuotaExceedederror is now a derived interface whatwg/fetch#1903

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fix(ext/web): remove QuotaExceededError from DOMException error names table denoland/deno#32151

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fix(ext/web): upgrade QuotaExceededError to DOMException derived interface denoland/deno#32244

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Upgrade QuotaExceededError to a DOMException derived interface#1465

Upgrade QuotaExceededError to a DOMException derived interface#1465
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