Convert TypeScript tsconfig paths to webpack alias paths

resolve-tsconfig-path-to-webpack-alias.js

const { resolve } = require('path');

/**
 * Resolve tsconfig.json paths to Webpack aliases
 * @param  {string} tsconfigPath           - Path to tsconfig
 * @param  {string} webpackConfigBasePath  - Path from tsconfig to Webpack config to create absolute aliases
 * @return {object}                        - Webpack alias config
 */
function resolveTsconfigPathsToAlias({
    tsconfigPath = './tsconfig.json',
    webpackConfigBasePath = __dirname,
} = {}) {
    const { paths } = require(tsconfigPath).compilerOptions;

    const aliases = {};

    Object.keys(paths).forEach((item) => {
        const key = item.replace('/*', '');
        const value = resolve(webpackConfigBasePath, paths[item][0].replace('/*', '').replace('*', ''));

        aliases[key] = value;
    });

    return aliases;
}

module.exports = resolveTsconfigPathsToAlias;

tsconfig.json

{
    "compilerOptions": {
        "module": "commonjs",
        "moduleResolution": "node",
        "outDir": "./dist",
        "allowJs": true,
        "target": "es6",
        "jsx": "react",
        "sourceMap": true,
        "noImplicitAny": true,
        "strictNullChecks": true,
        "baseUrl": "./",
        "lib": [
            "DOM",
            "ES5",
            "ES6",
            "es2017.object"
        ],
        "paths": {
            "Root/*": ["src/*"],
            "Components/*": ["src/components/*"],
            "Data/*": ["src/data/*"],
        }
    },

usage.tsx

import Banner from 'Components/banner';

webpack.config.js

// add paths to webpack

const resolveTsconfigPathsToAlias = require('./resolve-tsconfig-path-to-webpack-alias');

module.exports = {
  // ...
  resolve: {
    // ...
    alias: resolveTsconfigPathsToAlias({
	    tsconfigPath: '../tsconfig.json', // Using custom path
	    webpackConfigBasePath: '../', // Using custom path
    }),
  }
}

At lease tsconfig-paths-webpack-plugin doesn't work with webpack:^5:11.1 as it seems now.
I really appreciate this @nerdyman

Not sure you folks are aware of this https://www.npmjs.com/package/tsconfig-paths-webpack-plugin. May be it can help someone in the future.

this plugins replaces the context of resolve.alias object so u will not be able to add any custom aliases to your webpack configuration, and will be left in hands with only the one mentioned in tsconfig - what is kinda .... complicated )

@MisaGu Have you heard of the spread operator?

// add paths to webpack

const resolveTsconfigPathsToAlias = require('./resolve-tsconfig-path-to-webpack-alias');

module.exports = {
  // ...
  resolve: {
    // ...
    alias: {
      ...resolveTsconfigPathsToAlias({
	    tsconfigPath: '../tsconfig.json', // Using custom path
	    webpackConfigBasePath: '../', // Using custom path
      }),
      Utilities: path.resolve(__dirname, 'src/utilities/'),
      Templates: path.resolve(__dirname, 'src/templates/'),
    }
  }
}

@nerdyman It seems to me that this gist is missing the baseUrl. I had to edit to this to get it working.

const { resolve } = require('path');

/**
 * Resolve tsconfig.json paths to Webpack aliases
 * @param  {string} tsconfigPath           - Path to tsconfig
 * @param  {string} webpackConfigBasePath  - Path from tsconfig to Webpack config to create absolute aliases
 * @return {object}                        - Webpack alias config
 */
function resolveTsconfigPathsToAlias({
  tsconfigPath = './tsconfig.json',
  webpackConfigBasePath = __dirname,
} = {}) {
  const { paths, baseUrl } = require(tsconfigPath).compilerOptions;

  const aliases = {};

  Object.keys(paths).forEach((item) => {
    const key = item.replace('/*', '');
    const value = resolve(webpackConfigBasePath, baseUrl, paths[item][0].replace('/*', '').replace('*', ''));

    aliases[key] = value;
  });

  return aliases;
}

module.exports = resolveTsconfigPathsToAlias;

there is an issue in this configuration, because the first matched alias is selected instead of the most specific one

@its-dibo moved more specific first in the tsconfig paths as a workaround...