'this' implicitly has type 'any' because it does not have a type annotation

Question

The error is indeed fixed by inserting this with a type annotation as the first callback parameter. My attempt to do that was botched by simultaneously changing the callback into an arrow-function:

foo.on('error', (this: Foo, err: any) => { // DON'T DO THIS

It should've been this:

foo.on('error', function(this: Foo, err: any) {

or this:

foo.on('error', function(this: typeof foo, err: any) {

---

A GitHub issue was created to improve the compiler's error message and highlight the actual grammar error with this and arrow-functions.

For method decorator declaration with configuration "noImplicitAny": true, you can specify type of this variable explicitly depends on @tony19's answer

function logParameter(this:any, target: Object, propertyName: string) {
  //...
}

you can add

 "noImplicitAny": false,

to

tsconfig.json

as is says here