This is more than simple alias. This is also a multi-project src directory. Currently, create-react-app (CRA) does not support more than one src directory in the project. Monorepo, multi-repo and library projects with examples require more than one directories like src.

This is merely an alias and multi-source solution for CRA and this is not a replacement for multi-package management tools like Lerna.

This project requires the use of react-app-rewired, which allows to overwrite the Webpack configuration of CRA projects without ejecting them.

• quality and secure exports from outside src
• absolute imports
• any ./directory at root outside of src with Babel and CRA features

• monorepo projects
• multi-repo projects
• library projects with examples

• provided fully functional aliases and allows the use of Babel, JSX, etc. outside of src

• provided fully secure aliases and uses the same module scope plugin from the original create-react-app package for modules (instead of removing it), to minimize the probability of including unwanted code

yarn add --dev react-app-rewired react-app-rewire-alias

or

npm install --save-dev react-app-rewired react-app-rewire-alias

Modify config-overrides.js like this:

const {alias} = require('react-app-rewire-alias')

module.exports = function override(config) {
  alias({
    example: 'example/src',
    '@library': 'library/src',
  })(config)

  return config
}

This is compatible with customize-cra, just insert it into the override chain.

You can also configure your paths in your jsconfig.json or tsconfig.json like this:

{
  "compilerOptions": {
    "baseUrl": ".",
    "paths": {
      "example/*": ["example/src/*"],
      "@library/*": ["library/src/*"]
    }
  }
}

To keep aliases in one place, the provided configPaths() function loads the paths from jsconfig.json or tsconfig.json with slight adaptations. Use it like this:

const {alias, configPaths} = require('react-app-rewire-alias')

module.exports = function override(config) {
  alias(configPaths())(config)

  return config
}

The tsconfig.json is prioritized over the jsconfig.json in this scenario.

If you placed the paths in a custom file, use the function like so instead:

const {alias, configPaths} = require('react-app-rewire-alias')

module.exports = function override(config) {
  alias({
    ...configPaths('tsconfig.paths.json')
  })(config)

  return config
}

Integrating react-app-rewired into your project is very simple (see its documentation): Create config-overrides.js mentioned above in the project's root directory (the same including the package.json and src directory) and rewrite the package.json like this:

  "scripts": {
-   "start": "react-scripts start",
+   "start": "react-app-rewired start",
-   "build": "react-scripts build",
+   "build": "react-app-rewired build",
-   "test": "react-scripts test",
+   "test": "react-app-rewired test",
    "eject": "react-scripts eject"
}

That is all. Now you can continue to use yarn or npm start/build/test commands as usual.

CRA overwrites your tsconfig.json at runtime and removes paths from the tsconfig.json, which is not officially supported, with this message:

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

The suggested workaround is to move the paths to a different .json file, e.g. tsconfig.paths.json, like this:

/* tsconfig.paths.json */
{
  "compilerOptions": {
    "baseUrl": ".",
    "paths": {
      "example/*": ["example/src/*"],
      "@library/*": ["library/src/*"]
    }
  }
}

with that file's subsequent inclusion in the tsconfig.json using extends:

/* tsconfig.json */
{
  "extends": "./tsconfig.paths.json"
}

• keep only one node_modules directory

Confusions in deps versions may bring unclear errors or problems. For example application is not working without any error. Or another example is error in react-router - <Route> component do not see <Router> when actually code is correct and it falls with:

should not use Route or withRouter() outside a Router

This may be a result of some confusions in node_modules folders of multirepo projects. Same take place in plain create-react-app if some how one or more additional node_modulest directory appers in src.

To avoid this problems use only one main project node_modules directory.

• keep away from working with nested project

Default bundler configuration doesn't assume your configuration and may mix deps from node_modules from different projects (top project and nested project) so this may bring mentioned above confusions with deps versions. To avoid problems: do not install and run within nested project directly when it is nested or integrated in another one - but only independent toplevel configuration Or consider to eject or configure webpack manually.

• do not relay to deps versions synchronization

Some libraryes uses instanceof and other type comparisions. For example two objects created with same params in same code of same library version but installed in differenent node_modules and bundled separately - will mostly have same data and same behaviour but differen instance type. Such libraries will be unable to recognize its own objects and will lead to unpredictable behaviour. So use only one main project node_modules directory.