因为源代码是真相的最终来源。这里似乎是它的实现:

/*
 * Every module resolution kind can has its specific understanding how to load module from a specific path on disk
 * I.e. for path '/a/b/c':
 * - Node loader will first to try to check if '/a/b/c' points to a file with some supported extension and if this fails
 * it will try to load module from directory: directory '/a/b/c' should exist and it should have either 'package.json' with
 * 'typings' entry or file 'index' with some supported extension
 * - Classic loader will only try to interpret '/a/b/c' as file.
 */
type ResolutionKindSpecificLoader = (extensions: Extensions, candidate: string, onlyRecordFailures: boolean, state: ModuleResolutionState) => Resolved | undefined;

and

/**
 * Kinds of file that we are currently looking for.
 */
const enum Extensions {
    TypeScript  = 1 << 0, // '.ts', '.tsx', '.mts', '.cts'
    JavaScript  = 1 << 1, // '.js', '.jsx', '.mjs', '.cjs'
    Declaration = 1 << 2, // '.d.ts', etc.
    Json        = 1 << 3, // '.json'

    ImplementationFiles = TypeScript | JavaScript,
}

完整的文件是https://github.com/microsoft/TypeScript/blob/main/src/compiler/moduleNameResolver.ts。

来自官方文档(https://www.typescriptlang.org/docs/handbook/2/type-declarations.html#dts-files):

.d。Ts文件是仅包含类型信息的声明文件。这些文件不会产生.js输出;它们只用于类型检查。

因为源代码是真相的最终来源。这里似乎是它的实现:

/*
 * Every module resolution kind can has its specific understanding how to load module from a specific path on disk
 * I.e. for path '/a/b/c':
 * - Node loader will first to try to check if '/a/b/c' points to a file with some supported extension and if this fails
 * it will try to load module from directory: directory '/a/b/c' should exist and it should have either 'package.json' with
 * 'typings' entry or file 'index' with some supported extension
 * - Classic loader will only try to interpret '/a/b/c' as file.
 */
type ResolutionKindSpecificLoader = (extensions: Extensions, candidate: string, onlyRecordFailures: boolean, state: ModuleResolutionState) => Resolved | undefined;

and

/**
 * Kinds of file that we are currently looking for.
 */
const enum Extensions {
    TypeScript  = 1 << 0, // '.ts', '.tsx', '.mts', '.cts'
    JavaScript  = 1 << 1, // '.js', '.jsx', '.mjs', '.cjs'
    Declaration = 1 << 2, // '.d.ts', etc.
    Json        = 1 << 3, // '.json'

    ImplementationFiles = TypeScript | JavaScript,
}

完整的文件是https://github.com/microsoft/TypeScript/blob/main/src/compiler/moduleNameResolver.ts。

例如，你从npm得到了使用'alertifyjs'模块的问题。

创建“anyNameYoulike.d。Ts’(例如，你在SRC文件夹中创建了这个文件) 在文件中 声明模块'alertifyjs'; 在这里输入图像描述 在tsconfig.json 在“compilerOptions” "typeRoots": ["node_modules/@types"， "src/anyNameYoulike.d.ts"]

我从使用.d费力地映射JavaScript项目中学到了以下知识。ts文件。

使用。d。ts文件映射JavaScript需要你命名你的。d。Ts文件与你命名的.js文件相同。每个.js文件需要与.d. js文件保持内联(保持在同一个目录中)。Ts文件，具有相同的名称。指向需要.d中的类型的JS/TS代码。Ts文件到。d。ts文件。

例如:test.js和test.d.ts在testdir/文件夹中，然后你像这样在react组件中导入它:

import * as Test from "./testdir/test";

.d。Ts文件被导出为如下的命名空间:

export as namespace Test;
    
export interface TestInterface1{}
export class TestClass1{}

具体案例的工作示例:

假设你有my-module，你要通过npm共享它。

你用npm install my-module安装它

你可以这样使用它:

import * as lol from 'my-module';

const a = lol('abc', 'def');

模块的逻辑都在index.js中:

module.exports = function(firstString, secondString) {

  // your code

  return result
}

要添加类型，创建一个文件index.d.ts:

declare module 'my-module' {
  export default function anyName(arg1: string, arg2: string): MyResponse;
}

interface MyResponse {
  something: number;
  anything: number;
}