* Check nested conditional types for non-distributiveness * Rename to maybeNonDistributiveNameType * Add regression test
118 lines
3.3 KiB
TypeScript
118 lines
3.3 KiB
TypeScript
// @strict: true
|
|
// @declaration: true
|
|
|
|
// Mapped type 'as N' clauses
|
|
|
|
type Getters<T> = { [P in keyof T & string as `get${Capitalize<P>}`]: () => T[P] };
|
|
type TG1 = Getters<{ foo: string, bar: number, baz: { z: boolean } }>;
|
|
|
|
// Mapped type with 'as N' clause has no constraint on 'in T' clause
|
|
|
|
type PropDef<K extends keyof any, T> = { name: K, type: T };
|
|
|
|
type TypeFromDefs<T extends PropDef<keyof any, any>> = { [P in T as P['name']]: P['type'] };
|
|
|
|
type TP1 = TypeFromDefs<{ name: 'a', type: string } | { name: 'b', type: number } | { name: 'a', type: boolean }>;
|
|
|
|
// No array or tuple type mapping when 'as N' clause present
|
|
|
|
type TA1 = Getters<string[]>;
|
|
type TA2 = Getters<[number, boolean]>;
|
|
|
|
// Filtering using 'as N' clause
|
|
|
|
type Methods<T> = { [P in keyof T as T[P] extends Function ? P : never]: T[P] };
|
|
type TM1 = Methods<{ foo(): number, bar(x: string): boolean, baz: string | number }>;
|
|
|
|
// Mapping to multiple names using 'as N' clause
|
|
|
|
type DoubleProp<T> = { [P in keyof T & string as `${P}1` | `${P}2`]: T[P] }
|
|
type TD1 = DoubleProp<{ a: string, b: number }>; // { a1: string, a2: string, b1: number, b2: number }
|
|
type TD2 = keyof TD1; // 'a1' | 'a2' | 'b1' | 'b2'
|
|
type TD3<U> = keyof DoubleProp<U>; // `${keyof U & string}1` | `${keyof U & string}2`
|
|
|
|
// Repro from #40619
|
|
|
|
type Lazyify<T> = {
|
|
[K in keyof T as `get${Capitalize<K & string>}`]: () => T[K]
|
|
};
|
|
|
|
interface Person {
|
|
readonly name: string;
|
|
age: number;
|
|
location?: string;
|
|
}
|
|
|
|
type LazyPerson = Lazyify<Person>;
|
|
|
|
// Repro from #40833
|
|
|
|
type Example = {foo: string, bar: number};
|
|
|
|
type PickByValueType<T, U> = {
|
|
[K in keyof T as T[K] extends U ? K : never]: T[K]
|
|
};
|
|
|
|
type T1 = PickByValueType<Example, string>;
|
|
const e1: T1 = {
|
|
foo: "hello"
|
|
};
|
|
type T2 = keyof T1;
|
|
const e2: T2 = "foo";
|
|
|
|
// Repro from #41133
|
|
|
|
interface Car {
|
|
name: string;
|
|
seats: number;
|
|
engine: Engine;
|
|
wheels: Wheel[];
|
|
}
|
|
|
|
interface Engine {
|
|
manufacturer: string;
|
|
horsepower: number;
|
|
}
|
|
|
|
interface Wheel {
|
|
type: "summer" | "winter";
|
|
radius: number;
|
|
}
|
|
|
|
type Primitive = string | number | boolean;
|
|
type OnlyPrimitives<T> = { [K in keyof T as T[K] extends Primitive ? K : never]: T[K] };
|
|
|
|
let primitiveCar: OnlyPrimitives<Car>; // { name: string; seats: number; }
|
|
let keys: keyof OnlyPrimitives<Car>; // "name" | "seats"
|
|
|
|
type KeysOfPrimitives<T> = keyof OnlyPrimitives<T>;
|
|
|
|
let carKeys: KeysOfPrimitives<Car>; // "name" | "seats"
|
|
|
|
// Repro from #41453
|
|
|
|
type Equal<A, B> = (<T>() => T extends A ? 1 : 2) extends (<T>() => T extends B ? 1 : 2) ? true : false;
|
|
|
|
type If<Cond extends boolean, Then, Else> = Cond extends true ? Then : Else;
|
|
|
|
type GetKey<S, V> = keyof { [TP in keyof S as Equal<S[TP], V> extends true ? TP : never]: any };
|
|
|
|
type GetKeyWithIf<S, V> = keyof { [TP in keyof S as If<Equal<S[TP], V>, TP, never>]: any };
|
|
|
|
type GetObjWithIf<S, V> = { [TP in keyof S as If<Equal<S[TP], V>, TP, never>]: any };
|
|
|
|
type Task = {
|
|
isDone: boolean;
|
|
};
|
|
|
|
type Schema = {
|
|
root: {
|
|
title: string;
|
|
task: Task;
|
|
}
|
|
Task: Task;
|
|
};
|
|
|
|
type Res1 = GetKey<Schema, Schema['root']['task']>; // "Task"
|
|
type Res2 = GetKeyWithIf<Schema, Schema['root']['task']>; // "Task"
|
|
type Res3 = keyof GetObjWithIf<Schema, Schema['root']['task']>; // "Task"
|