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import { TestParams } from '../framework/fixture.js';
import { ResolveType, UnionToIntersection } from '../util/types.js';
import { assert } from '../util/util.js';
import { comparePublicParamsPaths, Ordering } from './query/compare.js';
import { kWildcard, kParamSeparator, kParamKVSeparator } from './query/separators.js';
export type JSONWithUndefined =
| undefined
| null
| number
| string
| boolean
| readonly JSONWithUndefined[]
// Ideally this would recurse into JSONWithUndefined, but it breaks code.
| { readonly [k: string]: unknown };
export interface TestParamsRW {
[k: string]: JSONWithUndefined;
}
export type TestParamsIterable = Iterable<TestParams>;
export function paramKeyIsPublic(key: string): boolean {
return !key.startsWith('_');
}
export function extractPublicParams(params: TestParams): TestParams {
const publicParams: TestParamsRW = {};
for (const k of Object.keys(params)) {
if (paramKeyIsPublic(k)) {
publicParams[k] = params[k];
}
}
return publicParams;
}
export const badParamValueChars = new RegExp(
'[' + kParamKVSeparator + kParamSeparator + kWildcard + ']'
);
export function publicParamsEquals(x: TestParams, y: TestParams): boolean {
return comparePublicParamsPaths(x, y) === Ordering.Equal;
}
export type KeyOfNeverable<T> = T extends never ? never : keyof T;
export type AllKeysFromUnion<T> = keyof T | KeyOfNeverable<UnionToIntersection<T>>;
export type KeyOfOr<T, K, Default> = K extends keyof T ? T[K] : Default;
/**
* Flatten a union of interfaces into a single interface encoding the same type.
*
* Flattens a union in such a way that:
* `{ a: number, b?: undefined } | { b: string, a?: undefined }`
* (which is the value type of `[{ a: 1 }, { b: 1 }]`)
* becomes `{ a: number | undefined, b: string | undefined }`.
*
* And also works for `{ a: number } | { b: string }` which maps to the same.
*/
export type FlattenUnionOfInterfaces<T> = {
[K in AllKeysFromUnion<T>]: KeyOfOr<
T,
// If T always has K, just take T[K] (union of C[K] for each component C of T):
K,
// Otherwise, take the union of C[K] for each component C of T, PLUS undefined:
undefined | KeyOfOr<UnionToIntersection<T>, K, void>
>;
};
/* eslint-disable-next-line @typescript-eslint/no-unused-vars */
function typeAssert<T extends 'pass'>() {}
{
type Test<T, U> = [T] extends [U]
? [U] extends [T]
? 'pass'
: { actual: ResolveType<T>; expected: U }
: { actual: ResolveType<T>; expected: U };
type T01 = { a: number } | { b: string };
type T02 = { a: number } | { b?: string };
type T03 = { a: number } | { a?: number };
type T04 = { a: number } | { a: string };
type T05 = { a: number } | { a?: string };
type T11 = { a: number; b?: undefined } | { a?: undefined; b: string };
type T21 = { a: number; b?: undefined } | { b: string };
type T22 = { a: number; b?: undefined } | { b?: string };
type T23 = { a: number; b?: undefined } | { a?: number };
type T24 = { a: number; b?: undefined } | { a: string };
type T25 = { a: number; b?: undefined } | { a?: string };
type T26 = { a: number; b?: undefined } | { a: undefined };
type T27 = { a: number; b?: undefined } | { a: undefined; b: undefined };
/* prettier-ignore */ {
typeAssert<Test<FlattenUnionOfInterfaces<T01>, { a: number | undefined; b: string | undefined }>>();
typeAssert<Test<FlattenUnionOfInterfaces<T02>, { a: number | undefined; b: string | undefined }>>();
typeAssert<Test<FlattenUnionOfInterfaces<T03>, { a: number | undefined }>>();
typeAssert<Test<FlattenUnionOfInterfaces<T04>, { a: number | string }>>();
typeAssert<Test<FlattenUnionOfInterfaces<T05>, { a: number | string | undefined }>>();
typeAssert<Test<FlattenUnionOfInterfaces<T11>, { a: number | undefined; b: string | undefined }>>();
typeAssert<Test<FlattenUnionOfInterfaces<T22>, { a: number | undefined; b: string | undefined }>>();
typeAssert<Test<FlattenUnionOfInterfaces<T23>, { a: number | undefined; b: undefined }>>();
typeAssert<Test<FlattenUnionOfInterfaces<T24>, { a: number | string; b: undefined }>>();
typeAssert<Test<FlattenUnionOfInterfaces<T25>, { a: number | string | undefined; b: undefined }>>();
typeAssert<Test<FlattenUnionOfInterfaces<T27>, { a: number | undefined; b: undefined }>>();
// Unexpected test results - hopefully okay to ignore these
typeAssert<Test<FlattenUnionOfInterfaces<T21>, { b: string | undefined }>>();
typeAssert<Test<FlattenUnionOfInterfaces<T26>, { a: number | undefined }>>();
}
}
export type Merged<A, B> = MergedFromFlat<A, FlattenUnionOfInterfaces<B>>;
export type MergedFromFlat<A, B> = {
[K in keyof A | keyof B]: K extends keyof B ? B[K] : K extends keyof A ? A[K] : never;
};
export function mergeParams<A extends {}, B extends {}>(a: A, b: B): Merged<A, B> {
for (const key of Object.keys(a)) {
assert(!(key in b), 'Duplicate key: ' + key);
}
return { ...a, ...b } as Merged<A, B>;
}
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