Warning is raised when a method is used outside of a method call.

Class functions don't preserve the class scope when passed as standalone variables.

Bad Practice

class MyClass {
  public log(): void {
    console.log(this);
  }
}

const instance = new MyClass();

// This logs the global scope (`window`/`global`), not the class instance
const myLog = instance.log;
myLog();

// This log might later be called with an incorrect scope
const { log } = instance;

Recommended

class MyClass {
  public logUnbound(): void {
    console.log(this);
  }

  public logBound = () => console.log(this);
}

const instance = new MyClass();

// logBound will always be bound with the correct scope
const { logBound } = instance;
logBound();

// .bind and lambdas will also add a correct scope
const dotBindLog = instance.logBound.bind(instance);
const innerLog = () => instance.logBound();

PickwickSoft / innovedu

No ignore rules found