What types does the function expect and return?

Question

RepoPilot · Accepted Answer

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

This is defined in the TypeScript declaration file [index.d.ts:L16-L17]:

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

The implementation in [index.js:L1-L2] enforces this by throwing a `TypeError` if the input is not a string:

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

The type test in [index.test-d.ts:L4] confirms the return type is string:

```typescript
expectType<string>(escapeStringRegexp('how much $ for a 🦄?'));
```

FOLLOW_UPS:
- What special characters does the function escape?
- Does the function handle Unicode characters differently?
- What is the `\x2d` escape in the second regex replacement?