fetch does not throw error with a malformed URL

[ghost]

Is this a bug report?

Yes

Have you read the Contributing Guidelines?

(Write your answer here.)

Environment

Environment:
OS: macOS Sierra 10.12.6
Node: 8.9.1
Yarn: 1.3.2
npm: 5.6.0
Watchman: 4.9.0
Xcode: Xcode 9.2 Build version 9C40b
Android Studio: 3.0 AI-171.4443003

Packages: (wanted => installed)
react: 16.0.0 => 16.0.0
react-native: 0.52.0 => 0.52.0

Steps to Reproduce

(Write your steps here:)

1. Make a fetch request to a malformed url like https://http:.malformedurl.com
2. The error is not propagated to the promise resolvers

Expected Behavior

The error should be thrown in the Javascript so that it can be caught in the catch block

Actual Behavior

(Write what happened. Add screenshots!)

Reproducible Demo

test = async () => {
    try {
      await fetch('https://http:.malformedurl.com/.jsapi/info')
      console.log('Fetch successful')
    }
    catch(error) {
      console.error(error); // never goes here
    }
    
  }
  componentDidMount() {
    this.test();
  }
  

[gedeagas]

Hello, @suparng-medallia thank you for your bug report.

after reviewing your code I must conclude this is not a bug and the code run as it should have.

catch(error) { console.error(error); // never goes here }

This part of the code is executed hence the red screen. if you want the error to be "thrown in the Javascript" ( log the error on debugger ) you can do that easily by changing the console.error() to console.log().

If you want to read more about debugging in react-native I suggest that you read the docs here
https://facebook.github.io/react-native/docs/debugging.html#in-app-errors-and-warnings

[react-native-bot]

Thanks for posting this! It looks like you may not be using the latest version of React Native, v0.53.0, released on January 2018. Can you make sure this issue can still be reproduced in the latest version?

I am going to close this, but please feel free to open a new issue if you are able to confirm that this is still a problem in v0.53.0 or newer.

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