Zhentiw - 博客园

2022年11月9日

[Typescript] Contra-variant type positions

摘要： Co-Variance: declare let b: string declare let c: string | number c = b // ✅ // string is a sub-type of string | number // all elements of string appe 阅读全文

posted @ 2022-11-09 17:18 Zhentiw 阅读(38) 评论(0) 推荐(0)

[Typescript] The naked type

摘要： So what is a nake type? Example: type UnionToIntersection<T> = (T extends any ? (x: T) => any : never) //... We check Tin a sub-type condition, T exte 阅读全文

posted @ 2022-11-09 02:47 Zhentiw 阅读(23) 评论(0) 推荐(0)

2022年11月8日

[Typescript] 90. Medium - Replace

摘要： Implement Replace<S, From, To> which replace the string From with To once in the given string S For example type replaced = Replace<'types are fun!', 阅读全文

posted @ 2022-11-08 14:45 Zhentiw 阅读(27) 评论(0) 推荐(0)

[Typescript] 89. Hard - Currying 1

摘要： TypeScript 4.0 is recommended in this challenge Currying is the technique of converting a function that takes multiple arguments into a sequence of fu 阅读全文

posted @ 2022-11-08 02:57 Zhentiw 阅读(35) 评论(0) 推荐(0)

[Typescript] 88. Hard - Simple Vue

摘要： Implement a simpiled version of a Vue-like typing support. By providing a function name SimpleVue (similar to Vue.extend or defineComponent), it shoul 阅读全文

posted @ 2022-11-08 02:43 Zhentiw 阅读(42) 评论(0) 推荐(0)

[Typescript] ThisType

摘要： This utility does not return a transformed type. Instead, it serves as a marker for a contextual this type. Note that the noImplicitThis flag must be 阅读全文

posted @ 2022-11-08 02:34 Zhentiw 阅读(69) 评论(0) 推荐(0)

2022年11月4日

[Typescript] Function scope in typescript

摘要： We have the following code which has compile error: async function readData(event?: Event | unknown): Promise<void> { // ... let text: string | undefi 阅读全文

posted @ 2022-11-04 16:00 Zhentiw 阅读(29) 评论(0) 推荐(0)

2022年11月3日

[Jest] Using Jest toHaveBeenCalledWith for testing primitive data types and partial objects

摘要： Example: expect(contextSpy.sendEncodedMessage).toHaveBeenCalledWith( expect.objectContaining({ correlationId: expect.objectContaining({ operationId: ' 阅读全文

posted @ 2022-11-03 17:57 Zhentiw 阅读(29) 评论(0) 推荐(0)

[Typescript] Zod in action

摘要： original code: Using type guards type Ticket = { workshopId: string attendeeId: string discountCode?: string } // this is a type guard function functi 阅读全文

posted @ 2022-11-03 15:35 Zhentiw 阅读(33) 评论(0) 推荐(0)

[Typescript] 87. Medium - DeepMutable

摘要： Implement a generic DeepMutable which make every parameter of an object - and its sub-objects recursively - mutable. For example type X = { readonly a 阅读全文

posted @ 2022-11-03 15:11 Zhentiw 阅读(28) 评论(0) 推荐(0)

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