vue.js Unit Test - Error in mounted hook

You may want to use Vue.config.errorHandler API which is introduced since v2.2.0.

You can declare a variable as an error-thrown flag (i.e. errorThrown).
```
let errorThrown = false;
```

Define the errorHandler function so that errorThrown will be switched to true when it's triggered.

Vue.config.errorHandler = function (err, vm, info) {  console.log(info);  if(info.includes('mounted')) {    errorThrown = true;  }};

Check errorThrown by using expect API in jasmine.

expect(errorThrown).toBe(false);  // Test will fail here

Check the working demo here.
In this way, errors occurred in mounted method will be catched and force unit test to fail.

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