Type 'string | number' is not assignable to type 'never' in Typescript Problem Description: When I write some code, I have some problems like that: function getObjectKeys<T extends object>(object: T) { return Object.keys(object) as (keyof T)[] } const props = { propA: 100, propB: ‘text’ } const store = { …props } getObjectKeys(props).forEach((key) => { … Read more
Generic Function with Omit gives could be instantiated with an arbitrary type error Problem Description: I’m trying to setup a generic function that maybe removes a field in a generic type. type MaybeID = {id?: string}; withoutID<K>(model: K & MaybeID): K { if (model.id) { const { id, …data } = model; // Type of … Read more
Conditional return type of class method depending on options in constructor Problem Description: I’m sure this is possible in TypeScript, but the closest resource I could find is this SO question which doesn’t seem to work for me. I have a class that gets options passed in the constructor, and based on that one of … Read more
Conditional return type of class method depending on options in constructor Problem Description: I’m sure this is possible in TypeScript, but the closest resource I could find is this SO question which doesn’t seem to work for me. I have a class that gets options passed in the constructor, and based on that one of … Read more
Best way to map types of two params of one function (And ensure type safety in the mapping type) Problem Description: I have a enum like this: export enum testEnum { key1 = "val1", key2 = "val2" } and I have a function that the first param is testEnum type, the second param will be … Read more
Why isn't TypeScript inferring rest params correctly in function implementation? Problem Description: I have defined a function that takes a string name and variable number of remaining params that it should infer from the provided interface. When calling this function, the inference is done correctly, but it is not inferred within the function implementation. interface … Read more
Why isn't TypeScript inferring rest params correctly in function implementation? Problem Description: I have defined a function that takes a string name and variable number of remaining params that it should infer from the provided interface. When calling this function, the inference is done correctly, but it is not inferred within the function implementation. interface … Read more
Tricky typing problems with a generic union type doing an intersection type Problem Description: I have stumbled upon a peculiar problem, and I have no idea how to fix this. I have a class with a generic type. This class contains a method with only one union parameters asking for the generic type or an … Read more
Tricky typing problems with a generic union type doing an intersection type Problem Description: I have stumbled upon a peculiar problem, and I have no idea how to fix this. I have a class with a generic type. This class contains a method with only one union parameters asking for the generic type or an … Read more
Tricky typing problems with a generic union type doing an intersection type Problem Description: I have stumbled upon a peculiar problem, and I have no idea how to fix this. I have a class with a generic type. This class contains a method with only one union parameters asking for the generic type or an … Read more