undefined_method

The method '{0}' isn't defined for the '{1}' function type.

The method '{0}' isn't defined for the type '{1}'.

The analyzer produces this diagnostic when a name is invoked without a receiver inside a class, enum, mixin, extension, or extension type, and it isn't defined by the enclosing declaration or in an enclosing scope. An invocation with an instance receiver, such as x.foo(), reports undefined_instance_member_read instead.

The following code produces this diagnostic because C doesn't have a member named removeMiddle:

class C {
  void removeLast() {}
​
  void f() {
    removeMiddle();
  }
}

If the identifier isn't defined, then either define it or replace it with the name of a method that is defined. The example above can be corrected by fixing the spelling of the method:

class C {
  void removeLast() {}
​
  void f() {
    removeLast();
  }
}