@sinclair/typebox
Version:
Json Schema Type Builder with Static Type Resolution for TypeScript
37 lines (36 loc) • 1.37 kB
JavaScript
import { CreateType } from '../create/type.mjs';
import { OptionalKind } from '../symbols/index.mjs';
import { Discard } from '../discard/index.mjs';
import { Never } from '../never/index.mjs';
import { Optional } from '../optional/index.mjs';
import { UnionCreate } from './union-create.mjs';
// ------------------------------------------------------------------
// TypeGuard
// ------------------------------------------------------------------
import { IsOptional } from '../guard/kind.mjs';
// prettier-ignore
function IsUnionOptional(types) {
return types.some(type => IsOptional(type));
}
// prettier-ignore
function RemoveOptionalFromRest(types) {
return types.map(left => IsOptional(left) ? RemoveOptionalFromType(left) : left);
}
// prettier-ignore
function RemoveOptionalFromType(T) {
return (Discard(T, [OptionalKind]));
}
// prettier-ignore
function ResolveUnion(types, options) {
const isOptional = IsUnionOptional(types);
return (isOptional
? Optional(UnionCreate(RemoveOptionalFromRest(types), options))
: UnionCreate(RemoveOptionalFromRest(types), options));
}
/** `[Json]` Creates an evaluated Union type */
export function UnionEvaluated(T, options) {
// prettier-ignore
return (T.length === 1 ? CreateType(T[0], options) :
T.length === 0 ? Never(options) :
ResolveUnion(T, options));
}