What types does the function expect and return?

Question

RepoPilot · Accepted Answer

The function `escapeStringRegexp` expects a **string** as input and returns a **string**.

According to the TypeScript definition in [index.d.ts:L16-L17]:

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

The function enforces this at runtime as well. If a non-string value is passed, it throws a `TypeError`, as shown in [index.js:L2-L4]:

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

FOLLOW_UPS:
- What special characters does the function escape?
- How does the function handle Unicode characters?
- What are the test cases for this function?