Distinguish between plain object types and class types

Search Terms

• plain object class type

Suggestion

Some way to distinguish an object type that only has Object in its prototype chain.

Use Cases

In this library, we use mapped types to convert immutable objects/arrays into their mutable representation. We never do this for class instances, so I need a way to skip the mapped type when an object type is actually a class type (in order to preserve readonly properties on class instances).

Examples

I have no suggestions for such syntax.

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, etc.)
• This feature would agree with the rest of TypeScript's Design Goals.

Related

https://stackoverflow.com/questions/53819550/distinguish-between-plain-objects-and-class-types#53819550

Inizia con il suggerimento e il relativo caso d’uso in Immer, quindi esamina la discussione correlata su Stack Overflow e i TypeScript Design Goals collegati nell’issue. Il lavoro sarebbe concluso quando fosse disponibile un meccanismo del sistema dei tipi chiaramente specificato per distinguere i tipi di oggetti semplici dai tipi di classe, con comportamento e sintassi concordati.