unnecessary_this_alias

Unnecessary 'this' alias.

The analyzer produces this diagnostic when a local variable is initialized to this and the variable is only used in ways that could just use this.

The following code produces this diagnostic because the local variable self is initialized to this, is never reassigned, and its only usage is a promotion check that could be performed on this directly under the this-promotion feature:

class C {
  void m() {
    var self = this;
    if (self is D) {
      // ...
    }
  }
}
​
class D extends C {}

Remove the local variable and use this directly:

class C {
  void m() {
    if (this is D) {
      // ...
    }
  }
}
​
class D extends C {}