Now you can manage Aliases for FrontEnd Workflow at one place

Aliases are very handy; be it in CLI or in FrontEnd development.

In previous post, we had seen the benefits of Aliases in Webpack

But what about other bundlers like Rollup? Or Test environment like Jest?

Problems

Fragmentation

In different tools, there is a different way to define aliases and this makes tricky to define and maintain the aliases.

Source of Truth

Another trouble is to maintain a single source of truth for the Aliases, as this configuration is everywhere, who gets to become the source of truth.

Onboarding Experience

Also for new joiners of Team, its hard to wrap the head around aliases once you are using them everywhere.

Manual Knowledge

These many configurations are Manual Knowledge because

Has to be maintained manually
Documentation is spread around and can easily go out of sync
Once the person who introduced aliases is gone, it starts falling apart

Solution

To solve the above mentioned problems, here is Alias-HQ

Alias-HQ picks up the configuration style of TypeScript Config (tsconfig.json) or VSCode Project Config (jsconfig.json)

And from those configs allows plugin style usage and manipulation of the aliases

And once the aliases configs are in place, you can imply import those aliases in your Bundler or Test setup scripts.

Lets consider following jsconfig.json:

{
  "compilerOptions": {
    "baseUrl": "src",
    "paths": {
      "@components/*": ["components/*"],
      "@assets/*": ["assets/*"],
      "@config/*": ["config/*"]
    }
  }
}

Now with the above project config, you can add aliases to your webpack in webpack.config.js as:

const aliases = require('alias-hq')

module.exports = {
  ...
  resolve: {
    alias: aliases.get('webpack')
  }
  ...
}

For rollup in rollup.config.js as:

import alias from '@rollup/plugin-alias';
import aliases = require('alias-hq')

module.exports = {
  ...
  plugins: [
    alias({
      entries: aliases.get('rollup')
    })
  ]
};

Or jest in jest.config.js

import aliases from 'alias-hq'

module.exports = {
  ...
  moduleNameMapper: aliases.get('jest'),
}

If are configuring Jest through package.json, you have to move to jest.config.js to be able to use AliasHQ for dynamic alias mapping generation

What about using aliases in Create React App?

To customise CRA, you need to use some packages which will tap into the configs from CRA. Though CRA does not recommend it and might break.

Such packages are:

Another way is to eject the configs to take full control over the Bundling and Testing configuration.

I tried to tap into webpack and jest configs with react-app-rewired, and this is my config to allow overrides and inject aliases:

// config-overrides.js
const aliases = require('alias-hq')

module.exports = {
  // The Webpack config to use when compiling your react app for development or production.
  webpack: (config, env) => ({
    ...config,
    resolve: {
      ...(config.resolve || {}),
      alias: {
        ...(config.resolve.alias || {}),
        ...aliases.get('webpack')
      }
    }
  }),
  // The Jest config to use when running your jest tests - note that the normal rewires do not
  // work here.
  jest: (config) => ({
    ...config,
    moduleNameMapper: {
      ...(config.moduleNameMapper || {}),
      ...aliases.get('jest')
    }
  })
}

With alias path configs in jsconfig.json as:

{
  "compilerOptions": {
    "baseUrl": "./src",
    "paths": {
      "@components/*": ["components/*"],
      "@reducers/*": ["reducers/*"],
      "@helpers/*": ["helpers/*"]
    }
  }
}

But what about TypeScript Project?

Though if you are using TypeScript, the configuration for alias-hq are picked up from tsconfig.json, so you need to add the path settings to tsconfig.json as:

{
  "compilerOptions": {
    ...,
    "baseUrl": "./src",
    "paths": {
      "@components/*": ["components/*"],
      "@reducers/*": ["reducers/*"],
      "@helpers/*": ["helpers/*"]
    }
  },
  ...
}

In some cases, the configuration of paths might be invalid and get removed automatically.

In such case, you will need to make a base config for TypeScript compiler and extend the main config with the base config

// tsconfig.base.json
{
  "compilerOptions": {
    ...,
    "baseUrl": "./src",
    "paths": {
      "@components/*": ["components/*"],
      "@reducers/*": ["reducers/*"],
      "@helpers/*": ["helpers/*"]
    }
  },
  ...
}

And the main config of TypeScript Compiler looks like:

// tsconfig.json
{
  "extends": "./tsconfig.base.json",
  "compilerOptions": {}
}

Conclusion

Here we learned how to use AliasHQ to add aliases to

Webpack
Rollup
Jest
Create React App

How do you manage your aliases?

Let me know through comments 💬 or on Twitter at @patel_pankaj_ and/or @time2hack

Pankaj Patel