[xdl][Project] Support app.config.js

[EvanBacon]

• _getExpAsync(): use slugify to transform config name from ThirdParty module
• Update types
• Remove unused variables
• Add support for app.config.js when starting a project on any platform
• Add support for app.config.js when getting build status, and starting a build.

Notes

• I guess you can make config changes then refresh the client (⌘R) to see them.

Test Plan

This effects:

• expo start
• expo start:web
• expo publish
• expo url

Each should be run with an app.config.js and app.json.

Test Project

app.json

{
  "expo": {
    "version": "1.0.0"
    // ...
  }
}

app.config.js

module.exports = function({ config, mode }) {
    return {
        ...config,
        name: "My Project - " + mode
    }
}

App.js

import React from 'react';
import { Text } from 'react-native';
import Constants from 'expo-constants';

export default () => <Text>Data: {Constants.manifest.name}</Text>

[jkhales]

🚀

[EvanBacon]

I'm thinking it might make sense to set an environment variable which we use for getting the environment in expo-cli. CC @fson

[fson]

What would this look like for a user of Expo CLI? Where would this environment variable usually be set?

[rungwe]

Hi @EvanBacon, in the app.config.js, there are two properties which we can extract,
config and mode
I do understand what config is, I am not sure what mode is? is this the release channel.

I am trying to get the release channel info so that I can apply some logic in the function to determine which config properties to use

module.exports = function({ config, mode }) { return { ...config, name: "My Project - " + mode } }

[arlyon]

@rungwe mode: packagerOpts.dev ? 'development' : 'production'