How to use import with absolute paths with Expo and React Native?

Question

I'm trying to use absolute import paths instead of relative paths with Expo and React Native.

I looked on the expo docs and couldn't find an answer... Searching for the subject in react community I found babel-plugin-module-resolver but it seems that Expo is already using it so I've changed my .babelrc to create some aliases:

{
  "presets": ["babel-preset-expo"],
  "env": {
    "development": {
      "plugins": [
        "transform-react-jsx-source",
        ["module-resolver", {
          "root": ["./app"],
          "alias": {
            "Components": "./app/components",
          }
        }]
      ]
    }
  }
}

But I got the following error:

    Unable to resolve module '@expo/vector-icons/glyphmaps/Entypo.json' 
    from '/Users/eduardoleal/Code/lua/rook/node_modules/@expo/vector-icons/Entypo.js': 
    Module does not exist in the module map or in these directories:   /Users/eduardoleal/Code/lua/rook/node_modules/@expo/vector-icons/node_modules/@expo/vector-icons/glyphmaps ,   /Users/eduardoleal/Code/lua/rook/node_modules/@expo/vector-icons/glyphmaps  This might be related to https://github.com/facebook/react-native/issues/4968 To resolve try the following:   
    1. Clear watchman watches: 'watchman watch-del-all'.   
    2. Delete the 'node_modules' folder: 'rm -rf node_modules && npm install'.   
    3. Reset packager cache: 'rm -fr $TMPDIR/react-*' or 'npm start --reset-cache'.
    ABI16_0_0RCTFatal -[ABI16_0_0RCTBatchedBridge stopLoadingWithError:] __34-[ABI16_0_0RCTBatchedBridge start]_block_invoke_2 _dispatch_call_block_and_release _dispatch_client_callout _dispatch_main_queue_callback_4CF __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ __CFRunLoopRun CFRunLoopRunSpecific GSEventRunModal UIApplicationMain main start 0x0 

Is there any easy way to import absolute paths?

Answer 1

Update: Expo v32.0.0 and up

Expo init is creating a babel.config.js for you. Just add the plugins key to your babel.config.js file and add your alias. The env key is not needed anymore.

module.exports = function(api) {
  api.cache(true)

  return {
    presets: ['babel-preset-expo'],
    plugins: [
      [
        'module-resolver',
        {
          alias: {
            assets: './assets',
            components: './src/components',
            modules: './src/modules',
            lib: './src/lib',
            types: './src/types',
            constants: './src/constants',
          },
        },
      ],
    ],
  }
}

Update: Changes for Expo.io SDK v20.0.0

Since SDK v20.0.0 you can use the normal Babel Expo presets

{
  "presets": ["babel-preset-expo"],
  "env": {
    "development": {
      "plugins": ["transform-react-jsx-source"]
    }
  },
  "plugins": [
    ["module-resolver", {
      "alias": {
        "alias-name": "./app",
      }
    }]
  ]
}

Expo.io SDK v19.0.0 and before

Without the root-element, separating plugins and changing presets to babel-preset-react-native-stage-0/decorator-support, an alias work for me.

Using Expo.io on Version 16.0.0
Found this in the Expo Forums here: https://forums.expo.io/t/relative-paths-with-expo/654/3

Can you verify that this works on your case too?

{
  "presets": ["babel-preset-react-native-stage-0/decorator-support"],
  "env": {
    "development": {
      "plugins": ["transform-react-jsx-source"]
    }
  },
  "plugins": [
    ["module-resolver", {
      "alias": {
        "alias-name": "./app",
      }
    }]
  ]
}

Answer 2

For latest expo users(sdk version >= 32).

Just add plugins property in your babel.config.js (find this file in project root directory).

module.exports = function (api) {
  api.cache(true);
  return {
    presets: ['babel-preset-expo'],
    plugins: [
      [
        'module-resolver',
        {
          alias: {
            'alias-name': './src/assets/bla/bla',
          },
        },
      ],
    ],
  };
};

Answer 3

After a while trying to get this working. I could resolve the problem with de following .babelrc:

{
  "presets": ["babel-preset-react-native-stage-0/decorator-support"],
  "env": {
    "development": {
      "plugins": ["transform-react-jsx-source"]
    }
  },
  "plugins": [
    ["module-resolver", {
      "alias": {
        "react-native-vector-icons": "@expo/vector-icons",
        "@expo/vector-icons/lib/create-icon-set": "react-native-vector-icons/lib/create-icon-set",
        "@expo/vector-icons/lib/icon-button": "react-native-vector-icons/lib/icon-button",
        "@expo/vector-icons/lib/create-icon-set-from-fontello": "react-native-vector-icons/lib/create-icon-set-from-fontello",
        "@expo/vector-icons/lib/create-icon-set-from-icomoon": "react-native-vector-icons/lib/create-icon-set-from-icomoon",
        "@expo/vector-icons/lib/icon-button": "react-native-vector-icons/lib/icon-button",
        "@expo/vector-icons/glyphmaps": "react-native-vector-icons/glyphmaps",
        "$components": "./app/components",
        "$config": "./app/config",
        "$helpers": "./app/helpers",
        "$navigators": "./app/navigators",
        "$reducers": "./app/reducers",
        "$screens": "./app/screens",
        "$images": "./assets/images",
        "$fonts": "./assets/fonts",
        "$icons": "./assets/icons",
        "$videos": "./assets/videos",
      }
    }]
  ]
}

I copied the content of babel-preset-expo to my .babelrc. It's not the best solution... but it works normally.

More details about it here