I want to generate the type keys from a combination of other type's key, like create dynamically object's keys.
type Swatch = {
dark: string;
light: string;
};
type ColorTheme = {
primary: Swatch;
secondary: Swatch;
};
// The result should be
type CombineType: {
// This keys are dinamically created as a combinatino of Swatch and ColorTheme keys
// primaryDark: string
// secondaryDark: string
}
You can achieve this by creating some kind of "generator" generic type that will give you the expected output.
type First = {
foo: string;
bar: string;
};
type Second = {
first: string;
second: string;
}
type JoinKeys<FK, SK> =
FK extends string ?
SK extends string ?
`${FK}${Capitalize<SK>}`
: never
: never;
type CombineTypes<F,S> = {
[key in JoinKeys<keyof F,keyof S>]: string;
};
type Test = CombineTypes<First, Second>;
Type JoinKeys simply combines passed in key values.
Type CombineTypes is a simple generic type that takes two params and outputs a type, where key is joined by keyof both passed params
You should extend these a bit to make sure only objects can be passed in and to have proper type coverage :)
Here is working example in Typescript Playground