Promise.catch as type of unknown when "useUnknownInCatchVariables": true

[gkiely]

Suggestion

Currently the promise .catch argument is typed as any.
Allow setting this as unknown for greater type safety via the "useUnknownInCatchVariables" flag.

somePromise.catch(e => {
  // e: any
});

🔍 Search Terms

.catch any
Promise any unknown

✅ Viability Checklist

My suggestion meets these guidelines:

• [ x ] This wouldn't be a breaking change in existing TypeScript/JavaScript code
• [ x ] This wouldn't change the runtime behavior of existing JavaScript code
• [ x ] This could be implemented without emitting different JS based on the types of the expressions
• [ x ] This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, new syntax sugar for JS, etc.)
• [ x ] This feature would agree with the rest of TypeScript's Design Goals.

⭐ Suggestion

See above

📃 Motivating Example

Related ticket: #6283

💻 Use Cases

Any promise based code using .catch is potentially unsafe using any.

[MartinJohns]

Duplicate of #45602. Used search terms: catch unknown in:title