ReferenceError: Property 'MessageEvent' doesn't exist

[DeveloperAspire]

I get this error in react native, after installing and setting up the mocking service by following the docs.

[kettanaito]

Hi, @DeveloperAspire. Thanks for reporting this.

Please, can you share a minimal reproduction repo for me to look at? Something definitely doesn't seem right with this error. It likely originates from the WebSocket support in MSW, but that is disabled for msw/native.

[DeveloperAspire]

@kettanaito thanks for your swift response, I have gone ahead to create a minimal repo to reproduce the error, here is the link to it: https://github.com/DeveloperAspire/msw-native-bug-replication

the readme contains information to quickly run it.

I am looking forward to your feedback

[Brandon-Perry]

+1 I ran into this problem as well

[rasulovdev]

+1

[diego-ferreira-vindi-zbra]

Has anyone found a solution to this problem? my team and I want to use msw in our expo/react native project but this is currently preventing us from doing so :(

[diego-ferreira-vindi-zbra]

Hi, @DeveloperAspire. Thanks for reporting this.

Please, can you share a minimal reproduction repo for me to look at? Something definitely doesn't seem right with this error. It likely originates from the WebSocket support in MSW, but that is disabled for msw/native.

Is there a workaround for this problem while we don't have a fix?

[gabrielnovaisgs]

+1

[algoORgoal]

I found a workaround on a blog.

Apparently, undefined properties are supposed to be added for mocking as below.

import "fast-text-encoding";
import "react-native-url-polyfill/auto";

function defineMockGlobal(name) {
  if (typeof global[name] === "undefined") {
    global[name] = class {
      constructor(type, eventInitDict) {
        this.type = type;
        Object.assign(this, eventInitDict);
      }
    };
  }
}

["MessageEvent", "Event", "EventTarget", "BroadcastChannel"].forEach(defineMockGlobal);

[MateusAndrade]

I found a workaround on a blog.

Apparently, undefined properties are supposed to be added for mocking as below.

import "fast-text-encoding";
import "react-native-url-polyfill/auto";

function defineMockGlobal(name) {
if (typeof global[name] === "undefined") {
global[name] = class {
constructor(type, eventInitDict) {
this.type = type;
Object.assign(this, eventInitDict);
}
};
}
}

["MessageEvent", "Event", "EventTarget", "BroadcastChannel"].forEach(defineMockGlobal);

This works for me! 🚀