eslint-plugin-typescript/docs/rules/no-non-null-assertion.md

TypeScript plugin for ESLint

# Disallows non-null assertions using the `!` postfix operator (no-non-null-assertion)

## Rule Details

Using non-null assertions cancels the benefits of the strict null-checking mode.

Examples of **incorrect** code for this rule:

```ts
interface Foo {
    bar?: string;
}

const foo: Foo = getFoo();
const includesBaz: boolean = foo.bar!.includes("baz");
```

Examples of **correct** code for this rule:

```ts
interface Foo {
    bar?: string;
}

const foo: Foo = getFoo();
const includesBaz: boolean = foo.bar && foo.bar.includes("baz");
```

## When Not To Use It

If you don't care about strict null-checking, then you will not need this rule.

## Further Reading

* [`no-non-null-assertion`](https://palantir.github.io/tslint/rules/no-non-null-assertion/) in [TSLint](https://palantir.github.io/tslint/)