How to use paths in tsconfig.json?

Question

I was reading about path-mapping in tsconfig.json and I wanted to use it to avoid using the following ugly paths:

The project organization is a bit weird because we have a mono-repository that contains projects and libraries. The projects are grouped by company and by browser / server / universal.

How can I configure the paths in tsconfig.json so instead of:

import { Something } from "../../../../../lib/src/[browser/server/universal]/...";

I can use:

import { Something } from "lib/src/[browser/server/universal]/...";

Will something else be required in the webpack config? or is the tsconfig.json enough?

Answer 1

This can be set up on your tsconfig.json file, as it is a TS feature.

You can do like this:

"compilerOptions": {
        "baseUrl": "src", // This must be specified if "paths" is.
         ...
        "paths": {
            "@app/*": ["app/*"],
            "@config/*": ["app/_config/*"],
            "@environment/*": ["environments/*"],
            "@shared/*": ["app/_shared/*"],
            "@helpers/*": ["helpers/*"]
        },
        ...

Have in mind that the path where you want to refer to, it takes your baseUrl as the base of the route you are pointing to and it's mandatory as described on the doc.

The character '@' is not mandatory.

After you set it up on that way, you can easily use it like this:

import { Yo } from '@config/index';

the only thing you might notice is that the intellisense does not work in the current latest version, so I would suggest to follow an index convention for importing/exporting files.

https://www.typescriptlang.org/docs/handbook/module-resolution.html#path-mapping

UPDATE Check out this example I made to showcase how is mapping into a single file:

https://github.com/ialex90/TypeScript-Node-Starter/commit/a4e8cc1f8f8d5176e0099e05b51f97b0ef4bebea

Answer 2

You can use combination of baseUrl and paths docs.

Assuming root is on the topmost src dir(and I read your image properly) use

// tsconfig.json
{
  "compilerOptions": {
    ...
    "rootDir": ".",
    "paths": {
      "lib/*": [
        "src/org/global/lib/*"
      ]
    }
  }
}

For webpack you might also need to add module resolution. For webpack2 this could look like

// webpack.config.js
module.exports = {
    resolve: {
        ...
        modules: [
            ...
            './src/org/global'
        ]
    }
}

Answer 3

Check this similar solutions with asterisk

  "baseUrl": ".",
  "paths": {
    "*": [
      "node_modules/*",
      "src/types/*"
    ]
  },

Answer 4

Alejandros answer worked for me, but as I'm using the awesome-typescript-loader with webpack 4, I also had to add the tsconfig-paths-webpack-plugin to my webpack.config file for it to resolve correctly

Answer 5

If you are using paths, you will need to change back absolute paths to relative paths for it to work after compiling typescript into plain javascript using tsc.

Most popular solution for this has been tsconfig-paths so far.

I've tried it, but it did not work for me for my complicated setup. Also, it resolves paths in run-time, meaning overhead in terms of your package size and resolve performance.

So, I wrote a solution myself, tscpaths.

I'd say it's better overall because it replaces paths at compile-time. It means there is no runtime dependency or any performance overhead. It's pretty simple to use. You just need to add a line to your build scripts in package.json.

The project is pretty young, so there could be some issues if your setup is very complicated. It works flawlessly for my setup, though my setup is fairly complex.

Answer 6

if typescript + webpack 2 + at-loader is being used, there is an additional step (@mleko's solution was only partially working for me):

// tsconfig.json
{
  "compilerOptions": {
    ...
    "rootDir": ".",
    "paths": {
      "lib/*": [
        "src/org/global/lib/*"
      ]
    }
  }
}    

// webpack.config.js
const { TsConfigPathsPlugin } = require('awesome-typescript-loader');

resolve: {
    plugins: [
        new TsConfigPathsPlugin(/* { tsconfig, compiler } */)
    ]
}

Advanced path resolution in TypeScript 2.0

Answer 7

/ starts from the root only, to get the relative path we should use ./ or ../

Answer 8

Its kind of relative path Instead of the below code

import { Something } from "../../../../../lib/src/[browser/server/universal]/...";

We can avoid the "../../../../../" its looking odd and not readable too.

So Typescript config file have answer for the same. Just specify the baseUrl, config will take care of your relative path.

way to config: tsconfig.json file add the below properties.

"baseUrl": "src",
    "paths": {
      "@app/*": [ "app/*" ],
      "@env/*": [ "environments/*" ]
    }

So Finally it will look like below

import { Something } from "@app/src/[browser/server/universal]/...";

Its looks simple,awesome and more readable..

Answer 9

It looks like there has been an update to React that doesn't allow you to set the "paths" in the tsconfig.json anylonger.

Nicely React just outputs a warning:

The following changes are being made to your tsconfig.json file:
  - compilerOptions.paths must not be set (aliased imports are not supported)

then updates your tsconfig.json and removes the entire "paths" section for you. There is a way to get around this run

npm run eject

This will eject all of the create-react-scripts settings by adding config and scripts directories and build/config files into your project. This also allows a lot more control over how everything is built, named etc. by updating the {project}/config/* files.

Then update your tsconfig.json

{
    "compilerOptions": {
        "baseUrl": "./src",
        {…}
        "paths": {
            "assets/*": [ "assets/*" ],
            "styles/*": [ "styles/*" ]
        }
    },
}

Answer 10

This works for me:

 yarn add --dev tsconfig-paths

 ts-node -r tsconfig-paths/register <your-index-file>.ts

This loads all paths in tsconfig.json. A sample tsconfig.json:

{
    "compilerOptions": {
        {…}
        "baseUrl": "./src",
        "paths": {
            "assets/*": [ "assets/*" ],
            "styles/*": [ "styles/*" ]
        }
    },
}

Make sure you have both baseUrl and paths for this to work

And then you can import like :

import {AlarmIcon} from 'assets/icons'

Answer 11

If I'm not mistaken, ./ means to start from the file's current directory while / means to start from the root. So you can replace all the ../s at the beginning with a /