react-native: Incorrect resolve js file as directory

In my project, I have directories structure like below:

/project-name
    /native
        /ios
        index.ios.js
    /src
        /containers
            App.js

And I require App.js in my index.ios.js:

var App = require('../src/containers/App');

I get a warning:

Unable to resolve module ../src/containers/App.js from /Users/username/Projects/project-name/native/index.ios.js

I thought we should not hide detail information about a happened error here:

// node_modules/react-native/packager/react-packager/src/DependencyResolver/DependencyGraph/ResolutionRequest.js`

const forgive = (error) => {
      if (error.type !== 'UnableToResolveError') {
        throw error;
      }

      console.warn(
        'Unable to resolve module %s from %s',
        toModuleName,
        fromModule.path
      );
      return null;
};

Anyway, I add a console.error(error) for this, and see following error message print out:

{ [UnableToResolveError: Invalid directory /Users/username/Projects/project-name/src/containers/App]
  message: 'Invalid directory /Users/username/Projects/project-name/src/containers/App',
  name: 'UnableToResolveError',
  type: 'UnableToResolveError' }

Why require('../src/containers/App') will try to resolve a directory there? I expected it should resolve ../src/containers/App.js.