Undefined errors when debugging React Native app in Chrome

[dbarros]

I am debugging a React Native application in Google Chrome, but I've noticed that I get a lot of "undefined" errors when I try and run functions, or variables, in the Console. Even though they are actually defined, and within scope.

I may have a file which looks something like this:

import { store } from '../store';
import { createField } from '../fields';

export function foo() {
    return 123;
}

export function bar() {
    return 456;              // breakpoint here
}

When I am stopped at a breakpoint in bar(), and I enter foo() in the Console, I get the following error:

VM163:1 Uncaught ReferenceError: foo is not defined
    at eval (eval at bar (main:105), <anonymous>:1:1)
    at bar (main.js:105)
    at Screen.navigationOptions (Screen.js:26)
    at applyConfig (createConfigGetter.js:28)
    at Object.getScreenOptions (createConfigGetter.js:88)
    at Object.getScreenOptions (createConfigGetter.js:73)
    at Object.getScreenOptions (createConfigGetter.js:73)
    at DrawerView.render (DrawerView.js:153)
    at finishClassComponent (ReactNativeFiber-dev.js:1721)
    at updateClassComponent (ReactNativeFiber-dev.js:1713)

The same error occurs when I enter store, or createField().

Is this some sort of configuration issue in the React Native project, or scope issue in the JavaScript?

Environment

Environment:
OS: macOS High Sierra 10.13.3
Node: 8.4.0
Yarn: Not Found
npm: 5.3.0
Watchman: 4.7.0
Xcode: Xcode 9.2 Build version 9C40b
Android Studio: Not Found

Packages: (wanted => installed)
react: ^16.0.0-beta.5 => 16.0.0
react-native: ^0.49.5 => 0.49.5

Expected Behavior

When I am at a breakpoint in a JS file, I would expect to be able to call functions defined within it, as well as be able to inspect variables which are in scope.

Actual Behavior

ReferenceError errors when trying the aforementioned.

[react-native-bot]

Thanks for posting this! It looks like your issue may refer to an older version of React Native. Can you reproduce the issue on the latest stable release?

Thank you for your contributions.

_{How to Contribute • What to Expect from Maintainers}

[dbarros]

I just upgraded to the latest, 0.54, but the app bombed on start-up with this error (as mentioned din these issues) #18223 #18190

So I down-graded to RN 0.53.3, and I'm still getting the same result as the aforementioned issue.

[dbarros]

Looks like it could be an issue with Babel babel/babel#1468