Zhentiw - 博客园

2022年12月12日

[Typescript] Using Generic Context to Avoid Distributivity in Conditional Types

摘要： Let's say we have: type Fruit = "apple" | "banana" | "orange"; We only want AppleOrBanana If we do as such: type Fruit = "apple" | "banana" | "orange" 阅读全文

posted @ 2022-12-12 15:52 Zhentiw 阅读(39) 评论(0) 推荐(0)

[Typescript] Extract the Result From Several Possible Function Shapes

摘要： Let's imagine you're building a type helper to extract out the value from several different 'parsers'. const parser1 = { parse: () => 1, }; const pars 阅读全文

posted @ 2022-12-12 15:40 Zhentiw 阅读(32) 评论(0) 推荐(0)

[Typescript] TS-toolbelt Split

摘要： Example 1 import { S } from "ts-toolbelt"; import { Equal, Expect } from "../helpers/type-utils"; type Names = [ "Matt Pocock", "Jimi Hendrix", "Eric 阅读全文

posted @ 2022-12-12 15:20 Zhentiw 阅读(123) 评论(0) 推荐(0)

[Typescript] Infer from an Interface

摘要： In this exercise we have an interface MyComplexInterface which is acting as a type helper. The interface takes arguments for Event, Context, Name, and 阅读全文

posted @ 2022-12-12 15:08 Zhentiw 阅读(40) 评论(0) 推荐(0)

2022年12月11日

[Typescript] Get object prop value

摘要： import { Equal, Expect } from "../helpers/type-utils"; type GetPropValue< T extends Record<PropertyKey, any>, P extends keyof T = "data" > = T extends 阅读全文

posted @ 2022-12-11 22:33 Zhentiw 阅读(52) 评论(0) 推荐(0)

[Typescript] 136. Medium - NonEmptyArray

摘要： type NonEmptyArray<T> = [T, ...Array<T>]; export const makeEnum = (values: NonEmptyArray<string>) => {}; makeEnum(["a"]); makeEnum(["a", "b", "c"]); / 阅读全文

posted @ 2022-12-11 22:16 Zhentiw 阅读(23) 评论(0) 推荐(0)

[Typescript] Constraining Types for Anything but null or undefined (T extends {})

摘要： export type Maybe<T extends {}> = T | null | undefined; type tests = [ // @ts-expect-error Maybe<null>, // @ts-expect-error Maybe<undefined>, Maybe<st 阅读全文

posted @ 2022-12-11 22:11 Zhentiw 阅读(27) 评论(0) 推荐(0)

[Typescript] 135. Easy - Maybe helper

摘要： import { Equal, Expect } from "../helpers/type-utils"; type Maybe<T> = T | null | undefined; type tests = [ Expect<Equal<Maybe<string>, string | null 阅读全文

posted @ 2022-12-11 22:03 Zhentiw 阅读(22) 评论(0) 推荐(0)

[Typescript] 134. Easy - Identity Helper

摘要： import { Equal, Expect } from "../helpers/type-utils"; type Identity<T> = T; type tests = [ Expect<Equal<Identity<1>, 1>>, Expect<Equal<Identity<"1">, 阅读全文

posted @ 2022-12-11 22:01 Zhentiw 阅读(37) 评论(0) 推荐(0)

[Typescript] Create an Object Whose Keys Are Derived From a Union

摘要： Let's say we have type TemplateLiteralKey = `${"user" | "post" | "comment"}${"Id" | "Name"}`; We want to make a type type ObjectOfKeys = unknown; In o 阅读全文

posted @ 2022-12-11 21:57 Zhentiw 阅读(38) 评论(0) 推荐(0)

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