guard-super-call.md

Requires a guard before calling a super method inside a Custom Element Lifecycle hook (guard-super-call)

Many element definitions may not include all the lifecycle hooks that HTMLElement provides. So when extending these elements, it is best practice to check that the super lifecycle hook exists before calling the super lifecycle hook.

Rule Details

This rule requires a guard before calling a super lifecycle hook.

The following patterns are considered warnings:

class MyOtherElement extends MyElement {
  connectedCallback() {
    super.connectedCallback();
    this.setAttribute('bar', 'baz');
  }
}

The following patterns are not warnings:

class MyOtherElement extends MyElement {
  connectedCallback() {
    if (super.connectedCallback) {
      super.connectedCallback();
    }
    this.setAttribute('bar', 'baz');
  }
}

When Not To Use It

If you wish to omit the super lifecycle hook's existence, you should not use this rule.