Assigning this
to a local variable is a way to reference parent context inside inner functions. In TypeScript when using arrow
functions this happens automatically.
This rule raises an issue when this
is assigned to a local variable.
Noncompliant code example
function Foo() {
let that = this; // Noncompliant
that.val = 0;
setInterval(function() {
that.val++;
}, 1000);
}
Compliant solution
function Foo() {
this.val = 0;
setInterval(() => {
this.val++;
}, 1000);
}
Exceptions
This rule ignores this
used for destructuring.
const { foo, bar } = this;
The rule also ignores alias references of this
in generators.
const self = this;
return function* () {
let result = self.next();
while (!result.done) {
yield result.value;
result = self.next();
}
};