模拟特定的函数重载签名

Posted 2023-02-21

【中文标题】模拟特定的函数重载签名

【英文标题】：Mocking specific function overload signature

【发布时间】：2021-12-16 04:27:18

【问题描述】：

我有以下代码

import  readdir  from 'fs/promises';

const files: string[] = await readdir('/original/file/path');

我正在尝试测试的内容

import * as fsPromisesModule from "fs/promises";

stub(fsPromisesModule, "readdir").callsFake(async (): Promise<string[]> => ['/test/file/path']);

但我收到以下错误

Type 'Promise<string[]>' is not assignable to type 'Promise<Dirent[]>'.
  Type 'string[]' is not assignable to type 'Dirent[]'.
    Type 'string' is not assignable to type 'Dirent'.ts(2322)

promises.d.ts 文件包含以下签名

    function readdir(
        path: PathLike,
        options?:
            | (ObjectEncodingOptions & 
                  withFileTypes?: false | undefined;
              )
            | BufferEncoding
            | null
    ): Promise<string[]>;

    function readdir(
        path: PathLike,
        options:
            | 
                  encoding: 'buffer';
                  withFileTypes?: false | undefined;
              
            | 'buffer'
    ): Promise<Buffer[]>;

    function readdir(
        path: PathLike,
        options?:
            | (ObjectEncodingOptions & 
                  withFileTypes?: false | undefined;
              )
            | BufferEncoding
            | null
    ): Promise<string[] | Buffer[]>;

    function readdir(
        path: PathLike,
        options: ObjectEncodingOptions & 
            withFileTypes: true;
        
    ): Promise<Dirent[]>;

存根中使用了最后一个签名，但我想使用第一个签名。如何告诉 TypeScript 这是我想在测试中使用的签名？

【问题讨论】：

你可以查看我的回答here

【参考方案1】：

根据@andreyunugros 链接的答案，以下工作有效；

(stub(fsPromisesModule, "readdir") as unknown as SinonStub<[p: PathLike], Promise<string[]>>).callsFake(async (): Promise<string[]> => (['/file/path/name']);