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no-this-before-super

Disallow this/super before calling super() in constructors

Recommended

The "extends": "eslint:recommended" property in a configuration file enables this rule

In the constructor of derived classes, if this/super are used before super() calls, it raises a reference error.

This rule checks this/super keywords in constructors, then reports those that are before super().

Rule Details

This rule is aimed to flag this/super keywords before super() callings.

Examples

Examples of incorrect code for this rule:

/*eslint no-this-before-super: "error"*/
/*eslint-env es6*/

class A extends B {
constructor() {
this.a = 0;
super();
}
}

class A extends B {
constructor() {
this.foo();
super();
}
}

class A extends B {
constructor() {
super.foo();
super();
}
}

class A extends B {
constructor() {
super(this.foo());
}
}

Examples of correct code for this rule:

/*eslint no-this-before-super: "error"*/
/*eslint-env es6*/

class A {
constructor() {
this.a = 0; // OK, this class doesn't have an `extends` clause.
}
}

class A extends B {
constructor() {
super();
this.a = 0; // OK, this is after `super()`.
}
}

class A extends B {
foo() {
this.a = 0; // OK. this is not in a constructor.
}
}

When Not To Use It

If you don’t want to be notified about using this/super before super() in constructors, you can safely disable this rule.

Version

This rule was introduced in ESLint v0.24.0.

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