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OmitByType

介绍​

从类型T中, 筛选属性类型不能赋值为'U'的属性集合.

ts
type OmitBoolean = OmitByType<{
  name: string
  count: number
  isReadonly: boolean
  isEnable: boolean
}, boolean> // { name: string; count: number }
ts
type OmitBoolean = OmitByType<{
  name: string
  count: number
  isReadonly: boolean
  isEnable: boolean
}, boolean> // { name: string; count: number }
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起点​

ts
/* _____________ Your Code Here _____________ */
 
type OmitByType<T, U> = any
 
/* _____________ Test Cases _____________ */
 
interface Model {
  name: string
  count: number
  isReadonly: boolean
  isEnable: boolean
}
 
type cases = [
  Expect<Equal<OmitByType<Model, boolean>, { name: string, count: number }>>,
Type 'false' does not satisfy the constraint 'true'.2344Type 'false' does not satisfy the constraint 'true'.
  Expect<Equal<OmitByType<Model, string>, { count: number, isReadonly: boolean, isEnable: boolean }>>,
Type 'false' does not satisfy the constraint 'true'.2344Type 'false' does not satisfy the constraint 'true'.
  Expect<Equal<OmitByType<Model, number>, { name: string, isReadonly: boolean, isEnable: boolean }>>,
Type 'false' does not satisfy the constraint 'true'.2344Type 'false' does not satisfy the constraint 'true'.
]
ts
/* _____________ Your Code Here _____________ */
 
type OmitByType<T, U> = any
 
/* _____________ Test Cases _____________ */
 
interface Model {
  name: string
  count: number
  isReadonly: boolean
  isEnable: boolean
}
 
type cases = [
  Expect<Equal<OmitByType<Model, boolean>, { name: string, count: number }>>,
Type 'false' does not satisfy the constraint 'true'.2344Type 'false' does not satisfy the constraint 'true'.
  Expect<Equal<OmitByType<Model, string>, { count: number, isReadonly: boolean, isEnable: boolean }>>,
Type 'false' does not satisfy the constraint 'true'.2344Type 'false' does not satisfy the constraint 'true'.
  Expect<Equal<OmitByType<Model, number>, { name: string, isReadonly: boolean, isEnable: boolean }>>,
Type 'false' does not satisfy the constraint 'true'.2344Type 'false' does not satisfy the constraint 'true'.
]
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解决方案​

Spoiler warning // Click to reveal answer
ts
 
type OmitByType<T, U> = {
  [P in keyof T as T[P] extends U ? never : P]: T[P]
}
 
ts
 
type OmitByType<T, U> = {
  [P in keyof T as T[P] extends U ? never : P]: T[P]
}
 
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