Typescript 部分更新类型的类型相等

有类型任务的:

type Task = {
  id: string;
  prop1: string;
  prop2: number;
}

我正在try 正确地键入一个参数，以便表达对任务的更新:

• ID-必填-查找合适的任务
• 任意数量的props -可选-任务props 的更新

我想出了两个替代方案:

type TaskUpdate1 = Pick<Task, 'id'> & Partial<Omit<Task, 'id'>>;
type TaskUpdate2 = Pick<Task, 'id'> & Partial<Task>;

在我看来，它们是相同的，但两个类型断言库声称它们是不同的:

import { Expect, Equal } from 'type-testing';
import { assert, _ } from "spec.ts";

type Task = {
  id: string;
  prop1: string;
  prop2: number;
}

type TaskUpdate1 = Pick<Task, 'id'> & Partial<Omit<Task, 'id'>>;
type TaskUpdate2 = Pick<Task, 'id'> & Partial<Task>;

type test_0 = Expect<Equal<TaskUpdate1, TaskUpdate2>>;

var x = {} as TaskUpdate1;
var y = {} as TaskUpdate2;

assert(x, y);

这些类型有什么不同(如果有，有什么不同？换句话说:是否存在属于一个而不属于另一个的值？)，或者是类型测试代码中的缺陷？

TS Playground个

Update个

这个问题显然是关于类型测试和规范的知识 我内联了这些库中的类型，以使问题更加独立:

/* type-testing: https://github.com/MichiganTypeScript/type-testing/ */
export type Equal<A, B> =
  (<T>() => T extends A ? 1 : 2) extends
  (<T>() => T extends B ? 1 : 2)
  ? true
  : false;

export type Expect<T extends true> = Equal<T, true>;

/* spec.ts: https://github.com/aleclarson/spec.ts */
// Give "any" its own class
export class Any {
  private _: true = true;
}

type TestExact<Left, Right> =
  (<U>() => U extends Left ? 1 : 0) extends (<U>() => U extends Right ? 1 : 0) ? Any : never;

type IsAny<T> = Any extends T ? ([T] extends [Any] ? 1 : 0) : 0;

export type Test<Left, Right> = IsAny<Left> extends 1
  ? IsAny<Right> extends 1
    ? 1
    : "❌ Left type is 'any' but right type is not"
  : IsAny<Right> extends 1
  ? "❌ Right type is 'any' but left type is not"
  : [Left] extends [Right]
  ? [Right] extends [Left]
    ? Any extends TestExact<Left, Right>
      ? 1
      : "❌ Unexpected or missing 'readonly' property"
    : "❌ Right type is not assignable to left type"
  : "❌ Left type is not assignable to right type";

type Assert<T, U> = U extends 1
  ? T // No error.
  : IsAny<T> extends 1
  ? never // Ensure "any" is refused.
  : U; // Return the error message.

export const assert: <Left, Right>(
  left: Assert<Left, Test<Left, Right>>,
  right: Assert<Right, Test<Left, Right>>
) => Right = () => ({}) as any;

/* My code */

type Task = {
  id: string;
  prop1: string;
  prop2: number;
}

type TaskUpdate1 = Pick<Task, 'id'> & Partial<Omit<Task, 'id'>>;
type TaskUpdate2 = Pick<Task, 'id'> & Partial<Task>;

type test_0 = Expect<Equal<TaskUpdate1, TaskUpdate2>>;

var x = {} as TaskUpdate1;
var y = {} as TaskUpdate2;

assert(x, y);