# @typescript-eslint/no-non-null-asserted-nullish-coalescing

> Disallow `!` on the left side of `??`

`??` gives a fallback for when the left side is `null` or `undefined`. A `!` on that side says it never is. If that's true, the fallback is dead code. If it isn't, the `!` is wrong. `??` handles both cases without it, so remove the `!`.

A `!` on the right side is allowed.

{/* Generated by src/codegen/lint-rule-docs.ts. Do not edit this section. */}

## Configure

Off by default. To turn it on:

```toml bunfig.toml
[lint.rules]
"@typescript-eslint/no-non-null-asserted-nullish-coalescing" = "error"
```

{/* End of the generated section. */}

## Examples

Reported:

{/* bad {"count": 2} */}
```ts
declare const settings: { theme?: string };
declare function findUser(id: string): { name: string } | null;

const theme = settings.theme! ?? "light";
const user = findUser("42")! ?? { name: "guest" };
```

Not reported:

{/* good */}
```ts
declare const settings: { theme?: string };
declare function findUser(id: string): { name: string } | null;

const theme = settings.theme ?? "light";
const user = findUser("42") ?? { name: "guest" };
```

Here the `!` is what lets you read `label` before it's assigned, so it's allowed:

{/* good */}
```ts
let label: string;

const text = label! ?? "untitled";
```