feat(orm): implement $is sub-model filter for delegate base models

[motopods]

Adds support for the $is filter operator on delegate (polymorphic) base model where clauses, enabling queries that filter by sub-model-specific fields.

What's new

When querying from a delegate base model, use $is to filter by sub-model type and/or sub-model-specific fields. Multiple sub-model entries are combined with OR semantics.

// Return only Video assets (includes RatedVideo since it extends Video)
await client.asset.findMany({
    where: { $is: { video: {} } },
});

// true value is equivalent to an empty filter — same as above
await client.asset.findMany({
    where: { $is: { video: true} },
});

// Filter on a sub-model-specific field
await client.asset.findMany({
    where: { $is: { video: { duration: { gt: 100 } } } },
});

// Combine a base field filter with a sub-model filter (AND)
await client.asset.findMany({
    where: {
        viewCount: { gt: 0 },
        $is: { video: { duration: { gt: 100 } } },
    },
});

// Multiple sub-models — OR semantics
// Returns: (Videos with duration > 100) OR (Images with format 'png')
await client.asset.findMany({
    where: {
        $is: {
            video: { duration: { gt: 100 } },
            image: { format: 'png' },
        },
    },
});

// Nested $is — for multi-level delegate hierarchies
// Asset.$is.video.$is.ratedVideo
await client.asset.findMany({
    where: {
        $is: {
            video: { $is: { ratedVideo: { rating: 5 } } },
        },
    },
});

// $is on an intermediate delegate
await client.video.findMany({
    where: { $is: { ratedVideo: { rating: 5 } } },
});

• Correlated EXISTS subqueries — Filters are translated into EXISTS (SELECT 1 FROM <submodel> WHERE id = <base>.id AND <discriminator> AND <sub-fields>) SQL, ensuring correct row-level scoping.
• Type-safe WhereInput — $SubModelWhereInput types are generated in crud-types.ts so TypeScript enforces valid sub-model fields at compile time.
• Runtime Zod validation — zod/factory.ts validates $is payloads at runtime, giving clear error messages for unknown sub-models or invalid field shapes.

Files changed

File	Change
packages/orm/src/client/crud-types.ts	Added $SubModelWhereInput and wired $is into WhereInput
packages/orm/src/client/crud/dialects/base-dialect.ts	Added buildIsFilter to emit correlated EXISTS subqueries
packages/orm/src/client/zod/factory.ts	Added runtime Zod validation for $is payloads
tests/e2e/orm/client-api/delegate.test.ts	End-to-end tests covering basic and nested $is filtering

Close #1740

Summary by CodeRabbit

• New Features

  • Added a top-level $is filter for delegate (polymorphic) base models to filter by sub-model type, including nested $is conditions, OR-combined multi-sub-model queries, and correlated-subquery semantics for inherited/base fields. Input validation now recognizes $is in where/filter schemas.

• Tests

  • Added e2e coverage validating $is behavior across base models, nested $is paths, nested predicates, and multi-sub-model queries.

[coderabbitai]

📝 Walkthrough

Walkthrough

Adds a $is polymorphic sub-model filter: type definitions, query-predicate construction, Zod where-schema generation, and end-to-end tests enabling base-model queries narrowed by concrete sub-model conditions (including OR semantics and nested $is).

Changes

Cohort / File(s)	Summary
Type System packages/orm/src/client/crud-types.ts	Added SubModelWhereInput and extended WhereInput for delegate models to optionally include $is?: SubModelWhereInput<...>, where each sub-model key maps to true or a nested WhereInput.
Query Builder / Dialect packages/orm/src/client/crud/dialects/base-dialect.ts	Added buildIsFilter handling in buildFilter: validates discriminator, maps camelCase keys to discriminator values, enforces discriminator equality, and, for nested filters, adds correlated EXISTS subqueries joined on id fields. Multiple sub-model entries are OR-combined.
Schema Validation (Zod) packages/orm/src/client/zod/factory.ts	makeWhereSchema now conditionally inserts an optional top-level $is strict object for delegate models; keys are lowercased sub-model names and values are true or a lazily-evaluated nested where schema.
Tests tests/e2e/orm/client-api/delegate.test.ts	Added e2e tests for $is on base models: true matches, nested sub-model predicates, combinations with base-model filters, OR across sub-models, and nested $is paths; additional seeded data included.

Estimated code review effort

🎯 4 (Complex) | ⏱️ ~45 minutes

Poem

I'm a rabbit in the model wood,
I sniff the $is where sub-models stood,
I hop through predicates, small and grand,
Combining checks with a correlated strand,
Polymorphic hops — query fields in hand! 🐇✨

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Linked Issues check	✅ Passed	The PR fully addresses the primary objectives of issue #1740: enabling queries on delegate base models using sub-model-specific properties with type safety and developer-friendly API.
Out of Scope Changes check	✅ Passed	All changes are directly related to implementing the $is sub-model filter feature; no unrelated modifications are present in the PR.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Title check	✅ Passed	The title 'feat(orm): implement $is sub-model filter for delegate base models' is directly related to the main change in the changeset, which introduces a new $is filter operator for delegate (polymorphic) base models across type definitions, dialect logic, validation, and tests.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ 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

• X
• Mastodon
• Reddit
• LinkedIn

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

[motopods]

@ymc9 Hi, what about you think of this?

[sanny-io]

This is very interesting. It may be better to use the lowercase-first name of the model (Video -> video).

Also, null matching the first query seems odd to me. Might it be better to use booleans, instead?

await client.asset.findMany({
    where: { $is: { video: true } },
});

[motopods]

@sanny-io You make a lot of sense.

[coderabbitai]

Actionable comments posted: 2

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@packages/orm/src/client/crud/dialects/base-dialect.ts`:
- Around line 367-382: The EXISTS subquery is built manually (using tmpAlias,
selectFrom and this.eb.exists) which bypasses delegate-aware helpers and causes
inherited-delegate filters from this.buildFilter to reference outer tables
incorrectly; replace the manual existsSubquery construction with the
dialect-aware helper (use the existing buildExistsExpression /
buildDelegateQueryHelpers pathway) so the subquery is created via the same
delegate-aware query builder, passing subModelName, subAlias, joinConditions and
subWhere (or subWhereFilter) into that helper instead of calling
this.eb.selectFrom directly; ensure the final condition still uses
discriminatorCheck and the helper-produced exists expression (instead of
this.eb.exists(existsSubquery)) so dialect-specific EXISTS workarounds and
proper alias joins are preserved.

In `@packages/orm/src/client/zod/factory.ts`:
- Around line 490-503: The $is filter currently uses z.object(...) which strips
unknown sub-model keys and hides typos; update the construction of
subModelSchema to use z.strictObject(...) instead (i.e. replace z.object(...)
with z.strictObject(...)) so unknown sub-model names will be rejected at
validation time; keep the same Object.fromEntries mapping of subModel names and
the existing union that references this.makeWhereSchema, and preserve the
.optional() on subModelSchema before assigning it to fields['$is'].

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: a7ffa087-26a0-464d-9e91-d1bac09d8a0b

📥 Commits

Reviewing files that changed from the base of the PR and between 39a0a28 and d62333d.

📒 Files selected for processing (4)

• packages/orm/src/client/crud-types.ts
• packages/orm/src/client/crud/dialects/base-dialect.ts
• packages/orm/src/client/zod/factory.ts
• tests/e2e/orm/client-api/delegate.test.ts