Better printing of `T & U` where this is equivalent to `Extract<T, U>`

Suggestion

🔍 Search Terms

Extract intersection union ide editor printing

✅ Viability Checklist

My suggestion meets these guidelines:

• 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 feature would agree with the rest of TypeScript's Design Goals.

⭐ Suggestion

There are many cases where T & U is equivalent to Extract<T, U>. However, the former has much worse type printing in these cases than the latter, leading to a much worse developer experience for this case.

I initially raised this as an eslint rule, but it would be very difficult to do do from that side (as explained in the comments of https://github.com/typescript-eslint/typescript-eslint/issues/2983

📃 Motivating Example

type A = Action & { type: 'action1' | 'action2' } 
// ({
//     type: 'action1';
//     a: number;
// } & {
//     type: 'action1' | 'action2';
// }) | ({
//     type: 'action2';
//     b: string;
// } & {
//     type: 'action1' | 'action2';
// })

type B = Extract<Action, { type: 'action1' | 'action2' }>
// {
//     type: 'action1';
//     a: number;
// } | {
//     type: 'action2';
//     b: string;
// }

https://www.typescriptlang.org/play?#code/C4TwDgpgBAggxsAlgewHZQLwCgoB8oDeUokAXFAOQCGCKqAjBQDRRXmoCuAtgEYQBOUAL458REhHLVaaAEzMoPcgGdg-RKgDmw0YWLhJlGkjQBmBXBVqN2kViwTYmWDPQAyPRKnG6jPEdd5YSgHAygAIWcAUQAPNWMAHngTVBZxA29XP3xpFKChAD4gA

💻 Use Cases

Improve developer experience, error messages, and IDE support.

Commencez par les exemples TypeScript motivants et la reproduction liée dans TypeScript Playground. Étudiez le comportement de l’affichage des types et de la prise en charge par l’IDE ; le travail sera considéré comme terminé lorsque les intersections équivalentes seront présentées sous une forme Extract-like plus claire, sans modifier le comportement à l’exécution.