expo: Constants.manifest.extra is always undefined (Windows)(Typescript)

Constants.manifest.extra is undefined repo here

Description

when trying to display the value of extra constants this gives undefined.

Expected Behavior

import Constants from 'expo-constants';

console.log("extra - ", Constants.manifest.extra);
//  extra - { "mode": "DEVELOPMENT" }

Observed Behavior

I have observed that setting the value directly in app.json continues as undefined.

import Constants from 'expo-constants';

console.log("extra - ", Constants.manifest.extra);
// extra - undefined

Environment

 Expo CLI 3.17.24 environment info:
    System:
      OS: Windows 10 10.0.18362
    Binaries:
      Node: 12.14.0 - C:\Program Files\nodejs\node.EXE
      Yarn: 1.19.1 - C:\Program Files (x86)\Yarn\bin\yarn.CMD
      npm: 6.13.4 - C:\Program Files\nodejs\npm.CMD
    npmPackages:
      expo: 37.0.8 => 37.0.8
      react: 16.13.1 => 16.13.1
      react-native: https://github.com/expo/react-native/archive/sdk-37.0.1.tar.gz => 0.61.4
    phone
      phone: simulator, emulator and Huawei
      platform: android
      model: LDN-LX3

Reproducible Demo

repo here

app.config.js

import { ExpoConfig, ConfigContext } from '@expo/config';
import manifiest from './package.json';

const Mode = {
  DEVELOPMENT: 'DEVELOPMENT',
  QA: 'QA',
  PRODUCTION: 'PRODUCTION',
}

export default ({ config }: ConfigContext): ExpoConfig => ({
  ...config,
  version: manifiest.version,
  // All values in extra will be passed to your app.
  extra: {
    mode: Mode.DEVELOPMENT,
  },
});

app.json

{
  "expo": {
    "name": "myapp",
    "slug": "myapp",
    "scheme": "my-app-schema",
    "privacy": "unlisted",
    "version": "1.0.1",
    "orientation": "portrait",
    "description": "My app description",
    "icon": "./assets/icon.png",
    "splash": {
      "image": "./assets/splash.png",
      "resizeMode": "cover"
    },
    "platforms": [
      "ios",
      "android",
      "web"
    ],
    "updates": {
      "fallbackToCacheTimeout": 0
    },
    "assetBundlePatterns": [
      "**/*"
    ],
    "android": {
      "package": "co.com.example.myapp",
      "versionCode": 1
    },
    "androidStatusBar": {
      "hidden": false,
      "translucent": true,
      "barStyle": "light-content",
      "backgroundColor": "#00000000"
    },
    "ios": {
      "supportsTablet": true,
      "bundleIdentifier": "co.com.example.myapp",
      "buildNumber": "1.0.0"
    }
  }
}

src/setup.constants.ts

import Constants from 'expo-constants';

console.log("extra", Constants.manifest.extra);

About this issue

Original URL
State: closed
Created 4 years ago
Reactions: 4
Comments: 20 (5 by maintainers)

Most upvoted comments

Just to update, actually it started working for both iOS and Android for me but only if the config is present on app.json as an empty key.

marconi on Jun 30, 2020

I was also experiencing this issue, but it appears to be a caching problem. I had a misconfigured variable being loaded into manifest.extra, and after correcting it I was still unable to see it despite trying several restarts of both the Expo client and server. The only thing that eventually worked is force clearing the data on the Expo client. After doing this, the updated environment variable is now being picked up and can be accessed from my application.

I also tried to repro the issue using @juandav’s repo, and it worked fine straight away. However if I manually changed the value in app.config.ts, the app would continue to load the old value.

davidmyerslup on Jul 23, 2020

Facing same issue for Expo CLI version 3.22.3 Windows 10 OS It works fine on Mac

alkeshattal on Jul 19, 2020

Hi @juandav, thanks for the repository (those things are useful 😄). But also here I’m getting the following output:

Running application on ONEPLUS A6003.
Object {
  "mode": "DEVELOPMENT",
}

Could you try upgrading your expo-cli and/or project with expo upgrade?

byCedric on Apr 30, 2020

Hi @juandav! Thanks for the issue report. Unfortunately, I can’t reproduce this behavior. For me, your provided code works fine. I did have to edit the scheme in your app.json to "scheme": "my-app-schema". The reason for this are the upper case letters, those are invalid. Could you try editing this on your end as well and restart the project with expo start --clear? 😄

If you are using the bare workflow instead, the manifest isn’t available. That might cause this issue for you too, but only if you are running bare instead of managed.

Hope it helps!

byCedric on Apr 30, 2020