no-unsafe-takeuntil.md

Avoid takeUntil subscription leaks (no-unsafe-takeuntil)

This rule effects failures whenever takeUntil is used in observable compositions that can leak subscriptions.

Although it's recommended that takeUntil be placed last - to ensure unsubscription from any inner observables - there are a number of operators that might need to be placed after it - like toArray or any other operator that depends upon a complete notification. The rule is aware of these operators (see the rule's options, below) and will not effect failures if they are placed after takeUntil.

Rule details

Examples of incorrect code for this rule:

const combined = source
    .pipe(takeUntil(notifier), combineLatest(b))
    .subscribe((value) => console.log(value));

Examples of correct code for this rule:

const combined = source
    .pipe(combineLatest(b), takeUntil(notifier))
    .subscribe((value) => console.log(value));

Options

This rule accepts a single option which is an object with alias and allow properties. The alias property is an array of names of operators that should be treated similarly to takeUntil and the allow property is an array of names of operators that are safe to use after takeUntil.

By default, the allow property contains all of the built-in operators that are safe to use after takeUntil.

{
    "rxjs/no-unsafe-takeuntil": [
        "error",
        {
            "alias": ["untilDestroyed"]
        }
    ]
}

The properties in the options object are themselves optional; they do not all have to be specified.

Further reading

• Avoiding takeUntil leaks