opencode/packages/core/src/schema.ts
2026-07-04 21:43:08 -04:00

89 lines
3 KiB
TypeScript

import { Schema } from "effect"
import {
AbsolutePath,
DateTimeUtcFromMillis,
NonNegativeInt,
optional,
PositiveInt,
RelativePath,
statics,
} from "@opencode-ai/schema/schema"
export { AbsolutePath, DateTimeUtcFromMillis, NonNegativeInt, optional, PositiveInt, RelativePath, statics }
/**
* Strip `readonly` from a nested type. Stand-in for `effect`'s `Types.DeepMutable`
* until `effect:core/x228my` ("Types.DeepMutable widens unknown to `{}`") lands.
*
* The upstream version falls through `unknown` into `{ -readonly [K in keyof T]: ... }`
* where `keyof unknown = never`, so `unknown` collapses to `{}`. This local
* version gates the object branch on `extends object` (which `unknown` does
* not) so `unknown` passes through untouched.
*
* Primitive bailout matches upstream — without it, branded strings like
* `string & Brand<"SessionID">` fall into the object branch and get their
* prototype methods walked.
*
* Tuple branch preserves readonly tuples (e.g. `ConfigPlugin.Spec`'s
* `readonly [string, Options]`); the general array branch would otherwise
* widen them to unbounded arrays.
*/
// eslint-disable-next-line @typescript-eslint/ban-types
export type DeepMutable<T> = T extends string | number | boolean | bigint | symbol | Function
? T
: T extends readonly [unknown, ...unknown[]]
? { -readonly [K in keyof T]: DeepMutable<T[K]> }
: T extends readonly (infer U)[]
? DeepMutable<U>[]
: T extends object
? { -readonly [K in keyof T]: DeepMutable<T[K]> }
: T
/**
* Nominal wrapper for scalar types. The class itself is a valid schema —
* pass it directly to `Schema.decode`, `Schema.decodeEffect`, etc.
*
* The runtime value remains an unwrapped primitive. `Schema.brand` supplies
* the primitive schema behavior and constructor validation, while the class
* supplies the nominal TypeScript identity.
* Apply checks and annotations to the underlying schema before wrapping it;
* schema rebuild operations intentionally return the underlying schema shape.
*
* @example
* class QuestionID extends Newtype<QuestionID>()("QuestionID", Schema.String) {}
*
* const id = QuestionID.make("question-1")
* Schema.decodeUnknownEffect(QuestionID)(input)
*/
type NewtypeSchema<Self, Tag extends string, S extends Schema.Top> = (abstract new (_: never) => {
readonly _newtype: Tag
}) &
Schema.Bottom<
Self,
S["Encoded"],
S["DecodingServices"],
S["EncodingServices"],
S["ast"],
S["Rebuild"],
S["~type.make.in"],
Self,
S["~type.parameters"],
Self,
S["~type.mutability"],
S["~type.optionality"],
S["~type.constructor.default"],
S["~encoded.mutability"],
S["~encoded.optionality"]
> &
Omit<S, keyof Schema.Top>
export function Newtype<Self>() {
return <const Tag extends string, S extends Schema.Top>(tag: Tag, schema: S): NewtypeSchema<Self, Tag, S> => {
abstract class Base {
declare readonly _newtype: Tag
}
Object.setPrototypeOf(Base, schema.pipe(Schema.brand(tag)))
return Base as unknown as NewtypeSchema<Self, Tag, S>
}
}