@skmtc/gen-typescript

A model generator (one Projection per schema component). Produces type aliases — not interfaces, not classes — so the output composes cleanly with structural-typing-heavy codebases.

Source

skmtc-generators/gen-typescript/src/

What it generates

For a User schema:

export type User = {
  id: string
  name: string
  email?: string
}

Per OAS-schema-variant TS classes (TsObject, TsArray, TsString, etc.) handle the dispatch. The toTsValue function in src/Ts.ts is the central switch from OasSchema.type to the right TS class.

Key decisions

• Type aliases, not interfaces. type User = {...} rather than interface User {...}. Type aliases compose better with mapped/ conditional types and don't suffer from declaration merging surprises.
• Configurable scalar map via a factory function: toTypescriptEntry({ scalars: {...}, replaceScalars: false }). Keys match OpenAPI format strings ('date-time', 'email') or GraphQL custom-scalar names ('DateTime', 'JSON'). The default map covers common formats; user overrides merge on top unless replaceScalars: true.
• Module-level scalar state. Calling toTypescriptEntry mutates module-level scalar state via setCustomScalars. Fine for the typical "one generation pipeline per process" model; parallel pipelines with different scalar maps would need to run sequentially.

What to learn from it

• The model-generator template — minimal entry, all the variation lives in the Projection.
• Per-OasSchema-variant sibling classes — TsObject, TsString, etc., each handling their own toString(). This mirrors the OasSchema discriminated union and is the canonical way to write a schema renderer.
• Factory-function config as an alternative to enrichments. When the config is global (scalar map) rather than per-operation, a factory function is cleaner than the per-operation enrichments path.

Common customizations when cloned

• Add new scalar mappings (a custom domain type like Money or ISBN).
• Change type to interface if your codebase prefers interfaces (e.g., for declaration merging with hand-written extensions).
• Tweak how nullable is represented (T | null vs T | undefined vs a custom Nullable<T> alias).
• Customize export paths (default lives in src/base.ts).

See also

• Projection bases reference — what the scaffold extends
• OasSchema variants reference — what toTsValue dispatches over
• gen-zod — sibling model generator with identical entry shape
• Projections and Snippets concept