Utility type to generate a type from another with a special care for the DX.
You can see this tool as an hardcode version of Pick
.
Features:
- ๐ Type safe
- ๐ฑ Minimal & lightweight
- โจ๏ธโ Autocompletion for fields
- ๐ฅ Automatically expands arrays and nullable/optional types
- ๐ Preview expanded types in intellisense
- ๐ซ Supports recursive & mutually recursive types
- โ Optional fields support
- ๐ Inspired by GraphQL
yarn add @shoooe/derive
Let's say that we have a type User
defined as:
type User = {
bestFriend: User | undefined;
favoriteBook: Book | null;
friends: User[] | undefined;
id: number;
name: string;
};
type Book = {
author: User;
isdn: number;
synopsis: string | null;
title: string | null | undefined;
subtitle?: string | null;
};
We can derive a subset of its properties via:
type Result = Derive<
User,
{
id: true;
name: true;
// Automatically expands nullable & optional types, which means that `null`
// and `undefined` will be added automatically to the resulting type if
// they existed in the target type.
bestFriend: {
name: true;
};
// Automatically expands arrays as well
friends: {
name: true;
// Supports mutually recursive types
favoriteBook: {
isdn: true;
title: true;
synopsis: true;
author: {
name: true;
};
};
};
}
>;
Which will result in:
type Result = {
id: number;
name: string;
bestFriend:
| {
name: string;
}
| undefined;
friends:
| {
name: string;
favoriteBook: {
isdn: number;
title: string | null | undefined;
synopsis: string | null;
author: {
name: string;
};
} | null;
}[]
| undefined;
};
- ts-essentials: comprehensive library with a different style for
DeepPick
(it doesn't do automatic expansion)
Special thanks to: