fix(svelte-query): handle shrinking createRawRef array by multiple entries (#10341) by ousamabenyounes · Pull Request #10892 · TanStack/query

ousamabenyounes · 2026-06-06T08:05:32Z

Summary

createQueries crashed with TypeError: 'deleteProperty' on proxy: trap returned falsish for property 'N' whenever two or more items were removed from its reactive array in a single update. The crash bubbled up from the $effect.pre in createQueries.svelte.ts, but the root cause sits in createRawRef (packages/svelte-query/src/containers.svelte.ts).

Root cause

createRawRef.update() iterates keysToRemove in ascending index order. For arrays, the deleteProperty trap decrements target.length on every successful delete — so after the first deletion the next stale index is no longer in target, the trap returns false, and delete throws in strict mode (ES modules). The trap was also returning false when the property was already absent, which is not how delete is meant to behave on a missing prop.

Fix

Two small, related changes in packages/svelte-query/src/containers.svelte.ts:

Sort keysToRemove numerically descending when newValue is an array, so every delete acts on the current tail and length-- stays valid.
Return true from deleteProperty for missing props — the spec semantic for delete on an absent property is a no-op, not a strict-mode throw. This makes the trap robust against any other path that might also try to delete a stale index.

Both are needed: (1) is the correctness fix; (2) is defense in depth that makes the trap behave like a normal object trap.

Verification

Added regression test should handle shrinking an array by more than one entry at once in packages/svelte-query/tests/containers.svelte.test.ts — shrinks [1, 2, 3, 4, 5] → [1, 2] → [1, 2, 3, 4] → [].
Test fails on main with the exact symptom from the issue:
TypeError: 'deleteProperty' on proxy: trap returned falsish for property '4' at src/containers.svelte.ts:93.
Test passes with the patch applied.
Full @tanstack/svelte-query:test:lib — 22 files, 164 tests, all pass.
test:eslint and test:types clean.

Changeset

@tanstack/svelte-query: patch — runtime bug fix, no public API change.

Generated by Ora Studio
Vibe coded by ousamabenyounes

Summary by CodeRabbit

Bug Fixes
- Fixed crashes that could occur when multiple items were removed from a reactive array in a single update.
- Improved stability when dynamic query collections shrink, including when all items are removed.
- Ensured array truncation and removals are handled reliably during rapid updates.
Tests
- Added regression coverage for shrinking reactive arrays by multiple elements, including reducing them to empty.

coderabbitai · 2026-06-06T08:05:44Z

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 869d71a6-178b-492d-a1a0-179afcb01a9e

📥 Commits

Reviewing files that changed from the base of the PR and between 320ed25 and de6487a.

📒 Files selected for processing (3)

.changeset/fix-svelte-query-shrink-array.md
packages/svelte-query/src/containers.svelte.ts
packages/svelte-query/tests/containers.svelte.test.ts

🚧 Files skipped from review as they are similar to previous changes (2)

packages/svelte-query/tests/containers.svelte.test.ts
packages/svelte-query/src/containers.svelte.ts

Included review availability: Your plan provides up to 10 included reviews per hour; 7 remain after this review.

📝 Walkthrough

Walkthrough

Updated createRawRef to delete removed array indices from the tail toward the head. Added regression coverage for multi-item reactive array shrinking and a patch changeset.

Changes

Array Shrinking Proxy Fix

Layer / File(s)	Summary
Proxy-safe array deletion and regression coverage `packages/svelte-query/src/containers.svelte.ts`, `packages/svelte-query/tests/containers.svelte.test.ts`	`update()` sorts removed array indices in descending order. Tests cover progressive shrinking, including removal to an empty array.
Release note `.changeset/fix-svelte-query-shrink-array.md`	Adds a patch changeset for the `createQueries` array-shrinking crash fix.

Estimated code review effort: 2 (Simple) | ~10 minutes

Merge Risk: ⚪ Minimal · up to de648

This is a localized fix for array shrinking in Svelte Query with regression coverage and passing checks; no actionable merge-blocking risk remains beyond normal review and validation.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly identifies the svelte-query fix for shrinking createRawRef arrays by multiple entries.
Description check	✅ Passed	The description explains the cause, fix, regression test, validation results, and changeset impact, despite not using the exact template headings.
Linked Issues check	✅ Passed	The code and regression test directly address issue `#10341` by supporting multiple array removals without proxy deletion errors.
Out of Scope Changes check	✅ Passed	The changeset, implementation fix, and regression test are directly related to issue `#10341` and the stated pull request objectives.
Docstring Coverage	✅ Passed	Docstring check was indeterminate for this PR — some files could not be analyzed in time. Not blocking.

✨ Finishing Touches

🧪 Generate unit tests (beta)

Create PR with unit tests

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

_{Comment @coderabbitai help to get the list of available commands.}

nx-cloud · 2026-06-11T00:34:35Z

View your CI Pipeline Execution ↗ for commit de6487a

Command	Status	Duration	Result
`nx affected --targets=test:sherif,test:knip,tes...`	✅ Succeeded	4m 16s	View ↗
`nx run-many --target=build --exclude=examples/*...`	✅ Succeeded	8s	View ↗

☁️ Nx Cloud last updated this comment at 2026-08-24 13:11:01 UTC

pkg-pr-new · 2026-06-11T00:37:27Z

More templates

@tanstack/angular-query-experimental

npm i https://pkg.pr.new/@tanstack/angular-query-experimental@10892

@tanstack/eslint-plugin-query

npm i https://pkg.pr.new/@tanstack/eslint-plugin-query@10892

@tanstack/lit-query

npm i https://pkg.pr.new/@tanstack/lit-query@10892

@tanstack/preact-query

npm i https://pkg.pr.new/@tanstack/preact-query@10892

@tanstack/preact-query-devtools

npm i https://pkg.pr.new/@tanstack/preact-query-devtools@10892

@tanstack/preact-query-persist-client

npm i https://pkg.pr.new/@tanstack/preact-query-persist-client@10892

@tanstack/query-async-storage-persister

npm i https://pkg.pr.new/@tanstack/query-async-storage-persister@10892

@tanstack/query-broadcast-client-experimental

npm i https://pkg.pr.new/@tanstack/query-broadcast-client-experimental@10892

@tanstack/query-core

npm i https://pkg.pr.new/@tanstack/query-core@10892

@tanstack/query-devtools

npm i https://pkg.pr.new/@tanstack/query-devtools@10892

@tanstack/query-persist-client-core

npm i https://pkg.pr.new/@tanstack/query-persist-client-core@10892

@tanstack/query-sync-storage-persister

npm i https://pkg.pr.new/@tanstack/query-sync-storage-persister@10892

@tanstack/react-query

npm i https://pkg.pr.new/@tanstack/react-query@10892

@tanstack/react-query-devtools

npm i https://pkg.pr.new/@tanstack/react-query-devtools@10892

@tanstack/react-query-next-experimental

npm i https://pkg.pr.new/@tanstack/react-query-next-experimental@10892

@tanstack/react-query-persist-client

npm i https://pkg.pr.new/@tanstack/react-query-persist-client@10892

@tanstack/solid-query

npm i https://pkg.pr.new/@tanstack/solid-query@10892

@tanstack/solid-query-devtools

npm i https://pkg.pr.new/@tanstack/solid-query-devtools@10892

@tanstack/solid-query-persist-client

npm i https://pkg.pr.new/@tanstack/solid-query-persist-client@10892

@tanstack/svelte-query

npm i https://pkg.pr.new/@tanstack/svelte-query@10892

@tanstack/svelte-query-devtools

npm i https://pkg.pr.new/@tanstack/svelte-query-devtools@10892

@tanstack/svelte-query-persist-client

npm i https://pkg.pr.new/@tanstack/svelte-query-persist-client@10892

@tanstack/vue-query

npm i https://pkg.pr.new/@tanstack/vue-query@10892

@tanstack/vue-query-devtools

npm i https://pkg.pr.new/@tanstack/vue-query-devtools@10892

commit: de6487a

risalfajar · 2026-06-26T04:30:48Z

Please merge this, this bug is making tanstack query svelte unusable

…tries (TanStack#10341) The `createRawRef` Proxy used by `createQueries` crashed with `TypeError: 'deleteProperty' on proxy: trap returned falsish for property 'N'` whenever the reactive query list was shrunk by two or more items in one update. Two compounding causes: 1. `update()` iterated `keysToRemove` in ascending index order. The trap decrements `target.length` after every deletion, so the next stale index was no longer `in target` and the trap returned `false`, which throws in strict mode (ES modules). 2. The trap returned `false` for missing props instead of treating delete on a nonexistent prop as a spec-compliant no-op. Fix: sort `keysToRemove` descending for arrays so each delete acts on the current tail, and return `true` from `deleteProperty` when the prop is already absent. Generated by Ora Studio Vibe coded by ousamabenyounes Co-Authored-By: Claude <noreply@anthropic.com>

Michael-Obele

It's all good

coderabbitai · 2026-08-24T13:05:25Z

Note

GitHub couldn't provide a complete incremental comparison for this pull request, so CodeRabbit is performing a full review instead. This review may take a little longer.

ousamabenyounes force-pushed the fix/issue-10341 branch from 7a1c6ce to 8c42f49 Compare July 11, 2026 00:21

renechoi mentioned this pull request Jul 27, 2026

fix(svelte-query): activate createQueries initialized with an empty array #11127

Merged

4 tasks

Michael-Obele approved these changes Aug 24, 2026

View reviewed changes

Merge branch 'main' into fix/issue-10341

de6487a

TkDodo merged commit cafd540 into TanStack:main Aug 24, 2026
9 checks passed

github-actions Bot mentioned this pull request Aug 24, 2026

ci: Version Packages #11271

Merged

Navigation Menu

Uh oh!

Uh oh!

fix(svelte-query): handle shrinking createRawRef array by multiple entries (#10341) - #10892

fix(svelte-query): handle shrinking createRawRef array by multiple entries (#10341)#10892
TkDodo merged 2 commits into
TanStack:mainfrom
ousamabenyounes:fix/issue-10341

ousamabenyounes commented Jun 6, 2026 •

edited by coderabbitai Bot

Loading

Uh oh!

coderabbitai Bot commented Jun 6, 2026 •

edited

Loading

Walkthrough

Changes

Uh oh!

nx-cloud Bot commented Jun 11, 2026 •

edited

Loading

Uh oh!

pkg-pr-new Bot commented Jun 11, 2026 •

edited

Loading

Uh oh!

risalfajar commented Jun 26, 2026

Uh oh!

Michael-Obele left a comment

Uh oh!

coderabbitai Bot commented Aug 24, 2026

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

Uh oh!

Uh oh!

Conversation

ousamabenyounes commented Jun 6, 2026 • edited by coderabbitai Bot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Summary

Root cause

Fix

Verification

Changeset

Summary by CodeRabbit

Uh oh!

coderabbitai Bot commented Jun 6, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Walkthrough

Changes

Uh oh!

nx-cloud Bot commented Jun 11, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

pkg-pr-new Bot commented Jun 11, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

risalfajar commented Jun 26, 2026

Uh oh!

Michael-Obele left a comment

Choose a reason for hiding this comment

Uh oh!

coderabbitai Bot commented Aug 24, 2026

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

ousamabenyounes commented Jun 6, 2026 •

edited by coderabbitai Bot

Loading

coderabbitai Bot commented Jun 6, 2026 •

edited

Loading

nx-cloud Bot commented Jun 11, 2026 •

edited

Loading

pkg-pr-new Bot commented Jun 11, 2026 •

edited

Loading