feat: add toArray() for includes subqueries

[kevin-dp]

Summary

• Adds toArray() wrapper that converts child Collections to plain Array<T> on parent rows
• When children change, the parent row is re-emitted with a fresh array snapshot
• Supports ordering and limits on toArray subqueries

Test plan

• Basic toArray produces arrays, not Collections
• Empty parents get []
• Adding/removing a child re-emits parent with updated array
• Array respects ORDER BY
• Ordered toArray with LIMIT applied per parent
• Existing Collection-based includes still work unchanged
• Full db test suite passes with no regressions

🤖 Generated with Claude Code

[changeset-bot]

🦋 Changeset detected

Latest commit: eb8ac7d

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 12 packages

Name	Type
@tanstack/db	Patch
@tanstack/angular-db	Patch
@tanstack/electric-db-collection	Patch
@tanstack/offline-transactions	Patch
@tanstack/powersync-db-collection	Patch
@tanstack/query-db-collection	Patch
@tanstack/react-db	Patch
@tanstack/rxdb-db-collection	Patch
@tanstack/solid-db	Patch
@tanstack/svelte-db	Patch
@tanstack/trailbase-db-collection	Patch
@tanstack/vue-db	Patch

Not sure what this means? Click here to learn what changesets are.

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

[pkg-pr-new]

More templates

• todos
• 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
• offline-transactions-react-native

@tanstack/angular-db

npm i https://pkg.pr.new/@tanstack/angular-db@1295

@tanstack/db

npm i https://pkg.pr.new/@tanstack/db@1295

@tanstack/db-ivm

npm i https://pkg.pr.new/@tanstack/db-ivm@1295

@tanstack/electric-db-collection

npm i https://pkg.pr.new/@tanstack/electric-db-collection@1295

@tanstack/offline-transactions

npm i https://pkg.pr.new/@tanstack/offline-transactions@1295

@tanstack/powersync-db-collection

npm i https://pkg.pr.new/@tanstack/powersync-db-collection@1295

@tanstack/query-db-collection

npm i https://pkg.pr.new/@tanstack/query-db-collection@1295

@tanstack/react-db

npm i https://pkg.pr.new/@tanstack/react-db@1295

@tanstack/rxdb-db-collection

npm i https://pkg.pr.new/@tanstack/rxdb-db-collection@1295

@tanstack/solid-db

npm i https://pkg.pr.new/@tanstack/solid-db@1295

@tanstack/svelte-db

npm i https://pkg.pr.new/@tanstack/svelte-db@1295

@tanstack/trailbase-db-collection

npm i https://pkg.pr.new/@tanstack/trailbase-db-collection@1295

@tanstack/vue-db

npm i https://pkg.pr.new/@tanstack/vue-db@1295

commit: 2087b61

[github-actions]

Size Change: +440 B (+0.46%)

Total Size: 96.5 kB

Filename	Size	Change
./packages/db/dist/esm/index.js	2.71 kB	+11 B (+0.41%)
./packages/db/dist/esm/query/builder/functions.js	792 B	+59 B (+8.05%)	🔍
./packages/db/dist/esm/query/builder/index.js	4.65 kB	+76 B (+1.66%)
./packages/db/dist/esm/query/compiler/index.js	2.69 kB	+19 B (+0.71%)
./packages/db/dist/esm/query/ir.js	757 B	+19 B (+2.57%)
./packages/db/dist/esm/query/live/collection-config-builder.js	7.91 kB	+256 B (+3.35%)

ℹ️ View Unchanged

Filename	Size
./packages/db/dist/esm/collection/change-events.js	1.39 kB
./packages/db/dist/esm/collection/changes.js	1.22 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	1.75 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	3.71 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/indexes/auto-index.js	742 B
./packages/db/dist/esm/indexes/base-index.js	766 B
./packages/db/dist/esm/indexes/btree-index.js	2.17 kB
./packages/db/dist/esm/indexes/lazy-index.js	1.1 kB
./packages/db/dist/esm/indexes/reverse-index.js	538 B
./packages/db/dist/esm/local-only.js	808 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/ref-proxy.js	1.05 kB
./packages/db/dist/esm/query/compiler/evaluators.js	1.43 kB
./packages/db/dist/esm/query/compiler/expressions.js	430 B
./packages/db/dist/esm/query/compiler/group-by.js	2.24 kB
./packages/db/dist/esm/query/compiler/joins.js	2.11 kB
./packages/db/dist/esm/query/compiler/order-by.js	1.5 kB
./packages/db/dist/esm/query/compiler/select.js	1.11 kB
./packages/db/dist/esm/query/expression-helpers.js	1.43 kB
./packages/db/dist/esm/query/live-query-collection.js	360 B
./packages/db/dist/esm/query/live/collection-registry.js	264 B
./packages/db/dist/esm/query/live/collection-subscriber.js	2.42 kB
./packages/db/dist/esm/query/live/internal.js	145 B
./packages/db/dist/esm/query/optimizer.js	2.62 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	952 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}

[samwillis]

Review from GPT5.4:

---

Findings

1. packages/db/src/query/builder/functions.ts, packages/db/src/query/builder/types.ts

toArray() isn’t wired into the result type inference, so the new public API loses type safety even though the runtime behavior works.

Right now toArray() returns a non-generic ToArrayWrapper, and ResultTypeFromSelect never maps that wrapper to Array<GetResult<...>>. As a result, a projection like issues: toArray(...) won’t infer as Issue[] on the parent row, which is a user-visible regression for the feature this PR is adding.

I think this needs a dedicated type-level branch in the select result inference so the wrapper unwraps to the child query result array type.

2. packages/db/tests/query/includes.test.ts, packages/db/tests/query/*.test-d.ts

The runtime coverage here is good, but there’s no .test-d.ts coverage for the new toArray() API. That leaves the typing regression above completely unguarded.

A focused type test around something like issues: toArray(q.from(...).select(...)) and an assertion that the parent result field is Array<...> would catch this immediately and help keep the public API stable.

[samwillis]

This is looking very good, other than the type issue that GPT5.4 found above, the other thing we need to do is ensure there are tests that validate the reactivity model:

• non-toArray subscribe to the main result collection and validate that changes that result in a child change don't trigger a change event on the parent.
• toArray same, but validate that there is an event on the child collection.

I believe these tests will pass, but we should have them as they are a core design feature.

[samwillis]