bug: TS7016 Could not find a declaration file for module

[ikatyang]

TypeScript Version: 2.2.1 / nightly (2.3.0-dev.20170301)

Command

tsc try.ts --noImplicitAny

Code

try.ts

import { x } from 'test'; // error TS7016: Could not find a declaration file for module 'test'.

module test

• package.json

  {
    "name": "test",
    "version": "1.0.0",
    "main": "lib/index"
  }

• lib/index.js

  "use strict";
  exports.__esModule = true;
  exports.x = { test: "only" };

• lib/index.d.ts

  export interface X {
    test: "only";
  }
  export declare const x: X;

Expected behavior:

non-error

Actual behavior:

try.ts(1,19): error TS7016: Could not find a declaration file for module 'test'. '~/tsc-test/node_modules/test/lib/index.js' implicitly has an 'any' type.

It works fine with typescript@2.1.6, or specified types field in package.json:

{
  "name": "test",
  "version": "1.0.0",
  "main": "lib/index",
  "types": "lib/index"
}

But I think this is a bug, since the documentation said:

Also note that if your main declaration file is named index.d.ts and lives at the root of the package (next to index.js) you do not need to mark the "types" property, though it is advisable to do so.

[mhegazy]

The behavior matches the documentation. the index.d.ts is not at the root, it is under lib.

The request to look up <value of package.json::main>.d.ts is tracked for #9854

[dhruvdutt]

Edit your tsconfig.json

"noImplicitAny": false

[ikatyang]

It was not about how to hide the error message but for what strategy does TS use to find declaration files.

I used to think that the "root" means "main" field (./lib/index.js in this case) in package.json, so that I just have to place ./lib/index.d.ts next to ./lib/index.js.

The fact is that the "root" means where package.json stands.

[dhruvdutt]

Ah! Alrighty. 👍

[TrungRueta]

I know this question is old. But i got same issue and found way to resolve:
from tsconfig.json of module you made. add :

"typeRoots": [
     "lib"
 ],

with "lib" is folder "outDir" value. Assume you put .d.ts files same place with .js file. and it will be good!

[bennycode]

I used to think that the "root" means "main" field (./lib/index.js in this case) in package.json, so that I just have to place ./lib/index.d.ts next to ./lib/index.js.

I agree that the documentation is quite misleading. It should say "next to package.json" instead of "next to index.js".