How to correctly type the configuration Object?

I have a working graph (i.e. It shows what it is supposed to show and behaves as expected on interactions).

Since I work in TypeScript, I get TS errors on callbacks in the definition of the configuration object, for instance:

(...)
point: {
  events: {
    click: function () {
      console.log(this)
      emit('result', phishingMap.value[this.category]) // the error is here
    }
  }
}
(...)

This piece of code yields the error

Property 'category' does not exist on type '{ click: () => void; }'. TS(2339)

How can I fix that by hinting about the content of this? The Highcharts documentation for TS does not mention any special steps to get the types declarations in.

EDIT: I know about traditional function and fat arrows (and the behaviour of this) but the problem is not in how to access the data, but about the data typing.

To fix the TypeScript error and provide type information for the this context inside the callback function, you can use an arrow function instead of a regular function.

point: {
  events: {
    click: () => {
      console.log(this);
      emit('result', phishingMap.value[this.category]);
    }
  }
}

If you're still encountering issues with type inference, you can explicitly annotate the type of this to provide TypeScript with additional information. For example:

point: {
  events: {
    click: function(this: Highcharts.Chart, event: Highcharts.ChartClickEvent) {
      console.log(this);
      emit('result', phishingMap.value[this.category]);
    }
  }
}

Here, this refer to the object you are writting. It has nothing to do with Highcharts but with how JS works while writting a function inside an object.

To keep the reference, you should use an arrow function

(...)
point: {
  events: {
    click: () => {
      console.log(this)
      emit('result', phishingMap.value[this.category]) // the error is here
    }
  }
}
(...)

Here is the big difference between a classic function and an arrow function :

The first one use the ref of the first parent

The second one use the ref of the class