Document that compiler.extends can be an array

[aryzing]

🔍 Search Terms

compiler.extends extends

✅ Viability Checklist

• This wouldn't be a breaking change in existing TypeScript/JavaScript code
• This wouldn't change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, new syntax sugar for JS, etc.)
• This isn't a request to add a new utility type: https://github.com/microsoft/TypeScript/wiki/No-New-Utility-Types
• This feature would agree with the rest of our Design Goals: https://github.com/Microsoft/TypeScript/wiki/TypeScript-Design-Goals

⭐ Suggestion

After merging #50403, the docs at https://www.typescriptlang.org/tsconfig/#extends haven't been updated to indicate that extends may be an array.

📃 Motivating Example

Users may only learn that extends may be an array if they find the PR above.