当 index.d.ts 存在时，TypeScript 不会导入 index.js

Question

I'm having strange behavior in TypeScript right now. In a folder separate from my source folder I have generated JS (protobufjs) with type definitions. When I try to import the index file from that folder I get the error [foldername]/index.d.ts is not a module . This even happens if I explicitly import [folder]/index or even [folder]/index.js .

Any idea what could be causing this?

tsconfig looks like this:

{
  "compilerOptions": {
    "target": "es2017",                          /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019' or 'ESNEXT'. */
    "module": "commonjs",
    "declaration": true,                   /* Generates corresponding '.d.ts' file. */
    "declarationMap": true,                /* Generates a sourcemap for each corresponding '.d.ts' file. */
    "sourceMap": true,                     /* Generates corresponding '.map' file. */
    "outDir": "./dist",                        /* Redirect output structure to the directory. */
    "rootDir": "./src",                       /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
    "composite": true,                     /* Enable project compilation */information */
    "removeComments": true,                /* Do not emit comments to output. */
    "strict": true,                           /* Enable all strict type-checking options. */
    "noImplicitAny": true,                 /* Raise error on expressions and declarations with an implied 'any' type. */
    "strictNullChecks": true,              /* Enable strict null checks. */
    "strictFunctionTypes": true,           /* Enable strict checking of function types. */
    "strictBindCallApply": true,           /* Enable strict 'bind', 'call', and 'apply' methods on functions. */
    "strictPropertyInitialization": true,  /* Enable strict checking of property initialization in classes. */
    "noImplicitThis": true,                /* Raise error on 'this' expressions with an implied 'any' type. */
    "alwaysStrict": true,                  /* Parse in strict mode and emit "use strict" for each source file. */
    "noUnusedLocals": true,                /* Report errors on unused locals. */
    "noUnusedParameters": true,            /* Report errors on unused parameters. */
    "noImplicitReturns": true,             /* Report error when not all code paths in function return a value. */
    "noFallthroughCasesInSwitch": true,    /* Report errors for fallthrough cases in switch statement. */
    "esModuleInterop": true                   /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */
  },
  "include": [ "src" ],
  "exclude": [ "test" ]
}

And possibly of note, the generated file I'm importing is under proto , in the same parent folder as src , and imported via eg import * as protos from "../../proto"; .

I'm also fairly certain this worked until recently, so some configuration might have changed or a module version updated that I haven't caught as this is a team project. Node 13.9.0, TypeScript 3.7.2.

Answer 1

I just tested this... this is my folder structure

_[project root]
 |_test
   |_test.js
   |_index.d.ts
 |_index.ts
 |_tsconfig.json
 |_package.json
 |_package.lock.json

The trick was adding the path to [project root]/test/index.d.ts to my tsconfig.json file.. After that, I no longer got the error about "not a module".. I am assuming your index.d.ts has the declare module statement in it...

// tsconfig.json
{
  "compilerOptions": {
    "target": "ESNEXT",                         
    "module": "commonjs", 
    "outDir": "./dist",
    "strict": true, 
    "esModuleInterop": true,  
    "forceConsistentCasingInFileNames": true
  },
  "include": [
    // THIS IS WHAT FIXED IT
    "test/index.d.ts"
  ]
}

// /test/index.d.ts
declare module 'test'

// /test/test.js
function test() {
    console.log('test');
}

// Not sure if you're using `module.exports` or not
export default test;

// index.ts
import test from './test/test';

test()