remote debugging when running server on different port

[ConnorMWGraham]

Description

I am running my server with "react-native start --port 9090". I can not use port 8081. Enabling Remote JS Debugging from my android emulator produces the following error:

The error seems to be easy to understand. It is trying to load a resource from localhost:8081, but can't find it because my server is running on port 9090

Reproduction

1. Start react-native server on different port "react-native start --port 9090"
2. Customize emulator to use port 9090 - ctrl+M > Dev Settngs > Debug server host & port for device >"10.0.2.2:9090"
3. Enable remote debugging - ctrl+M > Debug JS Remotely

Additional Information

• React Native version: 0.41.2
• Platform: Android
• Operating System: Windows
• Default Browser: Chrome

[brentvatne]

@ConnorMWGraham - did you rebuild the client using react-native run-android after changing the port?

[ConnorMWGraham]

No. I thought I had adjusted the client appropriately by doing ctrl+M > Dev Settngs > Debug server host & port for device >"10.0.2.2:9090". Where can I find the appropriate client configuration file?

[chmurson]

Same issue here. I have to run packager on different port since 8081 is already taken by McAfee processes ( cannot change that easily :( ). Everything works fine when I change host & port device via "in-app menu" (CMD+M). However it returns same error as in issue description when I turn on the remote debugger.

[anders-g-hansen]

I believe that #12095 which has a PR that has not yet been merged will partially fix the issue. I am able to work around this currently by setting a breakpoint in debuggerWorker.js and changing the port on the message.url before continuing (see screenshot). This is a painful work around, but until that PR is merged, not sure there is a better option.

However, I also needed to update the RealmReactModule.java file to change the hard coded port set for the Access-Control-Allow-Origin header to be the custom port I'm using (8088). Otherwise I get CORS errors.

            Response response = newFixedLengthResponse(jsonResponse);
            response.addHeader("Access-Control-Allow-Origin", "http://localhost:8088");
            return response;

After doing these two things, I was able to get the remote debugging to work.

[Rovack]

See #9935.

[hramos]

Solved in #12095