Unable to Resolve Module in React Native App with Expo

Question

I'm trying to port an existing RN app to use Expo.

I've tried the usual steps: kill the Expo process; trash node_modules; npm cache clean; npm install; watchman watch-del-all; rm -fr $TMPDIR/metro*; rm -fr $TMPDIR/haste*

/Users/matt/Documents/platform-prototype/XXXXXXXXXX/built/ios/debug/obj/XXXXXXXXXX/src/appWiring/ios/app.json:

{
  "name": "XXXXXXXX",
  "displayName": "XXXXXXXX",
  "expo": {
    "name": "XXXXXXXX",
    "slug": "xxxxxxxx",
    "entryPoint": "./index.js",
    "sdkVersion": "33.0.0",
    "version": "1.0",
    "platforms": [
      "ios",
      "android"
    ],
    "orientation": "portrait",
    "icon": "./assets/icon.png",
    "splash": {
      "image": "./assets/splash.png",
      "resizeMode": "contain",
      "backgroundColor": "#ffffff"
    },
    "ios": {
      "supportsTablet": true
    }
  }
}

/Users/matt/Documents/platform-prototype/XXXXXXXXXX/built/ios/debug/obj/XXXXXXXXXX/src/appWiring/ios/index.js:

import App from "./App";
import { registerRootComponent } from "expo";
registerRootComponent(App);

/Users/matt/Documents/platform-prototype/XXXXXXXXXX/built/ios/debug/obj/XXXXXXXXXX/src/appWiring/ios/.babelrc:

{
  "presets": ["babel-preset-expo"],
  "plugins": [
    ["module-resolver", {
      "root": [
        "../../../",
        "../../../../platform-client-react/src",
        "../../../../platform-client-react-native/src"
      ],
      "alias": {
          "@platform-client-react" : "../../../../platform-client-react/src/",
          "@platform-client-react-native" : "../../../../platform-client-react-native/src/"
      },
    }],
  ]
}

/Users/matt/Documents/platform-prototype/XXXXXXXXXX/built/ios/debug/obj/platform-client-react/src/index.js:

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
const ConsoleLogger_1 = require("./platform/client-react/logger/ConsoleLogger");
etc. etc. etc.

When I try to run the app in iOS simulator, expo dev tools shows this error:

error: bundling failed: Error: Unable to resolve module `../../../../platform-client-react/src` from `/Users/matt/Documents/platform-prototype/XXXXXXXXXXX/built/ios/debug/obj/XXXXXXXXXXX/src/appWiring/ios/App.js`: The module `../../../../platform-client-react/src` could not be found from `/Users/matt/Documents/platform-prototype/XXXXXXXXXXX/built/ios/debug/obj/XXXXXXXXXXX/src/appWiring/ios/App.js`. Indeed, none of these files exist:

  * `/Users/matt/Documents/platform-prototype/XXXXXXXXXXX/built/ios/debug/obj/platform-client-react/src(.native||.ios.js|.native.js|.js|.ios.json|.native.json|.json|.ios.ts|.native.ts|.ts|.ios.tsx|.native.tsx|.tsx)`

  * `/Users/matt/Documents/platform-prototype/XXXXXXXXXXX/built/ios/debug/obj/platform-client-react/src/index(.native||.ios.js|.native.js|.js|.ios.json|.native.json|.json|.ios.ts|.native.ts|.ts|.ios.tsx|.native.tsx|.tsx)`

In fact, the /Users/matt/Documents/platform-prototype/XXXXXXXXXXX/built/ios/debug/obj/platform-client-react/src/index.js file does actually exist, as you can see above. I don't know why the metro bundler thinks it doesn't.

kerosenekiwi kerosenekiwi · Accepted Answer · 2019-07-18T01:54:09

It says it all in the error "Indeed, none of these files exist". The issue is that it's looking for a file called App.js, not index.js. So to fix the problem all you need to do is create an App.js file and export the application through that file.

Unable to Resolve Module in React Native App with Expo

1 Answers