@tango-ts/core-types

Responsibility

The pure type layer of Tango. Defines the type-level contract of a model field (FieldDef) and the inference engine that derives every downstream shape from a model definition: InferSelect, InferInsert, InferUpdate, and Lookups. This package has zero runtime — it emits no JavaScript and imports nothing.

What it responds to

Consumes a Fields map (Record<string, FieldDef>) — the type the @tango-ts/orm model() function produces from f.* builders — and produces the inferred types the rest of the framework (ORM, serializers, admin, views) builds on.

Functionality

• FieldDef<TsType, Nullable, HasDefault> — phantom-typed field contract.
• InferSelect<F> — the row shape read from the DB (nullable fields include null).
• InferInsert<F> — the create shape (nullable / defaulted fields are optional).
• InferUpdate<F> — partial update shape.
• Lookups<F> — the fully-checked filter object; per-field lookups are gated by the field's value type (string vs number/date vs common).
• Prettify, UnionToIntersection — type utilities.

Design patterns that matter here

• Single source of truth (P2): every shape is derived here from the field map. No hand-written row interfaces anywhere in the codebase.
• Zero runtime: never add a runtime value to this package. Phantom markers are __-prefixed and declared by the runtime Field class in @tango-ts/orm.
• No any: the "any field" constraint is FieldDef<unknown, boolean, boolean>.

Public contract

Everything re-exported from src/index.ts (all export type). Changing a signature here is a contract change and requires its own PR.

Testing

• Type-level (vitest --typecheck via expectTypeOf): test/infer.test-d.ts, including negative cases (@ts-expect-error) that assert invalid lookups and wrong value types fail to compile.