Can I import *.d.ts instead of require it?

Question

I have some module lib in node_modules and I want to use it. I wrote lib.d.ts for this.

Files looks like:

/src/
    main.ts (imports `lib`)
/types/
    lib.d.ts

In file main.ts I can write this code:

/// <reference path="../types/lib.d.ts" />
import {some} from 'lib';

And it works.

But when I try to use import for ambient declaration file:

import '../types/lib';
import {some} from 'lib';

it compiles without errors, but in resulting JS I can find require for this file:

require('../types/lib');
const lib_1 = require('lib');

With error in runtime of missing file ../types/lib – it's just an ambient declaration file without resulting file.

Why compiler did not remove import of *.d.ts file?
Can I use import somehow, or I must use reference instead?

Solution:

If you don't want to use reference directives, you can just add required *.d.ts to files, included by your tsconfig.json.

My tsconfig.json was:

{
    "compilerOptions": {
        "module": "commonjs",
        "target": "es2015",
        "lib": ["es2016"],
        "noImplicitAny": true,
        "noImplicitReturns": true,
        "noImplicitThis": true,
        "strictNullChecks": true,
        "noFallthroughCasesInSwitch": true,
        "noUnusedLocals": true,
        "noUnusedParameters": true,
        "noEmitOnError": true,
        "newLine": "LF",
        "forceConsistentCasingInFileNames": true,
        "removeComments": true,
        "declaration": false,
        "sourceMap": false,
        "outDir": "../build",
        "types": [
            "node"
        ]
    },
    "files": [
        "index.ts"
    ]
}

Early I tried to add my .d.ts to types section, but in this case tcs is trying to find this file in node_modules/@types directory.

After suggestion I tried to add file in files section:

    "files": [
        "index.ts",
        "types/lib.d.ts"
    ]

It's works and seems as a good solution.

Answer 1

You don't have to import an ambient definition file.

You can manually /// <reference it. But the right way is just to make it available for the compiler through the file tsconfig.json.

An example of tsconfig.json that includes anything but node_modules:

{
    "compilerOptions": {
        "module": "commonjs",
        "target": "es5"
    },
    "exclude": [
        "node_modules"
    ]
}

The documentation on tsconfig.json is here.