What types does the function expect and return?

Question

RepoPilot · Accepted Answer

The `escapeStringRegexp` function expects a **string** parameter and returns a **string**.

According to the TypeScript type definition in [index.d.ts:L16-L17], the function signature is:

```typescript
export default function escapeStringRegexp(string: string): string;
```

At runtime, the function validates its input in [index.js:L2-L4]:

```javascript
if (typeof string !== 'string') {
	throw new TypeError('Expected a string');
}
```

If a non-string value is passed, it throws a `TypeError`. Otherwise, it processes the string and returns an escaped string with RegExp special characters escaped.

FOLLOW_UPS:
- What characters does the function escape?
- Why does the function use `\xnn` escaping for hyphens?
- How does the function handle Unicode characters?