test: Add regression tests for BTreeIndex infinite loop with undefined keys

[KyleAMathews]

🎯 Changes

This PR adds comprehensive regression tests for GitHub issue #1186, which describes an infinite loop in BTreeIndex.takeInternal when using orderBy() and limit() on collections containing items with undefined indexed values.

The test suite includes:

• Basic tests for take() and takeReversed() with undefined indexed values
• Tests mixing undefined and defined indexed values
• Tests with multiple items sharing the same undefined key
• Full end-to-end tests reproducing the exact scenario from issue Infinite loop in BTreeIndex.takeInternal when using orderBy and limit with undefined indexed values #1186 using live queries with orderBy and limit
• Tests combining where, orderBy, and limit with undefined values

All tests include a 5-second timeout to catch infinite loops during test execution.

Root Cause (documented in test comments):
When nextHigherPair(undefined) is called, it returns the minimum pair from the B-tree. If that minimum key is itself undefined, the method returns [undefined, undefined]. After processing, the code sets key = pair[0] (which is undefined) and calls nextHigherPair(undefined) again, returning the same pair and creating an infinite loop.

✅ Checklist

• I have followed the steps in the Contributing guide.
• I have tested this code locally with pnpm test:pr.

🚀 Release Impact

• This change affects published code, and I have generated a changeset.
• This change is docs/CI/dev-only (no release).

Note: This is a test-only addition that documents the bug for future reference and validation once the underlying issue is fixed.

https://claude.ai/code/session_01RKBKXMoKVe1hSXGy3VVEFo

[changeset-bot]

⚠️ No Changeset found

Latest commit: ca5ad65

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

[pkg-pr-new]

More templates

• todos
• offline-transactions-react-native
• tanstack-start-example-basic
• @tanstack/db-example-paced-mutations-demo
• tanstack-start-db-projects-example
• @tanstack/db-example-react-todo
• @tanstack/db-example-solid-todo

@tanstack/angular-db

npm i https://pkg.pr.new/@tanstack/angular-db@1191

@tanstack/db

npm i https://pkg.pr.new/@tanstack/db@1191

@tanstack/db-ivm

npm i https://pkg.pr.new/@tanstack/db-ivm@1191

@tanstack/electric-db-collection

npm i https://pkg.pr.new/@tanstack/electric-db-collection@1191

@tanstack/offline-transactions

npm i https://pkg.pr.new/@tanstack/offline-transactions@1191

@tanstack/powersync-db-collection

npm i https://pkg.pr.new/@tanstack/powersync-db-collection@1191

@tanstack/query-db-collection

npm i https://pkg.pr.new/@tanstack/query-db-collection@1191

@tanstack/react-db

npm i https://pkg.pr.new/@tanstack/react-db@1191

@tanstack/rxdb-db-collection

npm i https://pkg.pr.new/@tanstack/rxdb-db-collection@1191

@tanstack/solid-db

npm i https://pkg.pr.new/@tanstack/solid-db@1191

@tanstack/svelte-db

npm i https://pkg.pr.new/@tanstack/svelte-db@1191

@tanstack/trailbase-db-collection

npm i https://pkg.pr.new/@tanstack/trailbase-db-collection@1191

@tanstack/vue-db

npm i https://pkg.pr.new/@tanstack/vue-db@1191

commit: ca5ad65

[github-actions]

Size Change: 0 B

Total Size: 90.9 kB

ℹ️ View Unchanged

Filename	Size
./packages/db/dist/esm/collection/change-events.js	1.39 kB
./packages/db/dist/esm/collection/changes.js	1.19 kB
./packages/db/dist/esm/collection/events.js	388 B
./packages/db/dist/esm/collection/index.js	3.32 kB
./packages/db/dist/esm/collection/indexes.js	1.1 kB
./packages/db/dist/esm/collection/lifecycle.js	1.68 kB
./packages/db/dist/esm/collection/mutations.js	2.34 kB
./packages/db/dist/esm/collection/state.js	3.49 kB
./packages/db/dist/esm/collection/subscription.js	3.62 kB
./packages/db/dist/esm/collection/sync.js	2.41 kB
./packages/db/dist/esm/deferred.js	207 B
./packages/db/dist/esm/errors.js	4.7 kB
./packages/db/dist/esm/event-emitter.js	748 B
./packages/db/dist/esm/index.js	2.69 kB
./packages/db/dist/esm/indexes/auto-index.js	742 B
./packages/db/dist/esm/indexes/base-index.js	766 B
./packages/db/dist/esm/indexes/btree-index.js	1.93 kB
./packages/db/dist/esm/indexes/lazy-index.js	1.1 kB
./packages/db/dist/esm/indexes/reverse-index.js	513 B
./packages/db/dist/esm/local-only.js	837 B
./packages/db/dist/esm/local-storage.js	2.1 kB
./packages/db/dist/esm/optimistic-action.js	359 B
./packages/db/dist/esm/paced-mutations.js	496 B
./packages/db/dist/esm/proxy.js	3.75 kB
./packages/db/dist/esm/query/builder/functions.js	733 B
./packages/db/dist/esm/query/builder/index.js	4.09 kB
./packages/db/dist/esm/query/builder/ref-proxy.js	1.05 kB
./packages/db/dist/esm/query/compiler/evaluators.js	1.42 kB
./packages/db/dist/esm/query/compiler/expressions.js	430 B
./packages/db/dist/esm/query/compiler/group-by.js	1.81 kB
./packages/db/dist/esm/query/compiler/index.js	2.02 kB
./packages/db/dist/esm/query/compiler/joins.js	2.07 kB
./packages/db/dist/esm/query/compiler/order-by.js	1.45 kB
./packages/db/dist/esm/query/compiler/select.js	1.06 kB
./packages/db/dist/esm/query/expression-helpers.js	1.43 kB
./packages/db/dist/esm/query/ir.js	673 B
./packages/db/dist/esm/query/live-query-collection.js	360 B
./packages/db/dist/esm/query/live/collection-config-builder.js	5.42 kB
./packages/db/dist/esm/query/live/collection-registry.js	264 B
./packages/db/dist/esm/query/live/collection-subscriber.js	1.93 kB
./packages/db/dist/esm/query/live/internal.js	145 B
./packages/db/dist/esm/query/optimizer.js	2.56 kB
./packages/db/dist/esm/query/predicate-utils.js	2.97 kB
./packages/db/dist/esm/query/subset-dedupe.js	921 B
./packages/db/dist/esm/scheduler.js	1.3 kB
./packages/db/dist/esm/SortedMap.js	1.3 kB
./packages/db/dist/esm/strategies/debounceStrategy.js	247 B
./packages/db/dist/esm/strategies/queueStrategy.js	428 B
./packages/db/dist/esm/strategies/throttleStrategy.js	246 B
./packages/db/dist/esm/transactions.js	2.9 kB
./packages/db/dist/esm/utils.js	924 B
./packages/db/dist/esm/utils/browser-polyfills.js	304 B
./packages/db/dist/esm/utils/btree.js	5.61 kB
./packages/db/dist/esm/utils/comparison.js	852 B
./packages/db/dist/esm/utils/cursor.js	457 B
./packages/db/dist/esm/utils/index-optimization.js	1.51 kB
./packages/db/dist/esm/utils/type-guards.js	157 B

_{compressed-size-action::db-package-size}

[github-actions]

Size Change: 0 B

Total Size: 3.7 kB

ℹ️ View Unchanged

Filename	Size
./packages/react-db/dist/esm/index.js	225 B
./packages/react-db/dist/esm/useLiveInfiniteQuery.js	1.17 kB
./packages/react-db/dist/esm/useLiveQuery.js	1.34 kB
./packages/react-db/dist/esm/useLiveSuspenseQuery.js	559 B
./packages/react-db/dist/esm/usePacedMutations.js	401 B

_{compressed-size-action::react-db-package-size}