MapTypes

介绍

实现MapTypes<T,R>, 转换对象T中的类型为由R结构定义的不同类型

ts
type StringToNumber = { mapFrom: string; mapTo: number;}
MapTypes<{iWillBeANumberOneDay: string}, StringToNumber> // gives { iWillBeANumberOneDay: number; }

ts
type StringToNumber = { mapFrom: string; mapTo: number;}
MapTypes<{iWillBeANumberOneDay: string}, StringToNumber> // gives { iWillBeANumberOneDay: number; }

Be aware that user can provide a union of types:

ts
type StringToNumber = { mapFrom: string; mapTo: number;}
type StringToDate = { mapFrom: string; mapTo: Date;}
MapTypes<{iWillBeNumberOrDate: string}, StringToDate | StringToNumber> // gives { iWillBeNumberOrDate: number | Date; }

ts
type StringToNumber = { mapFrom: string; mapTo: number;}
type StringToDate = { mapFrom: string; mapTo: Date;}
MapTypes<{iWillBeNumberOrDate: string}, StringToDate | StringToNumber> // gives { iWillBeNumberOrDate: number | Date; }

If the type doesn't exist in our map, leave it as it was:

ts
type StringToNumber = { mapFrom: string; mapTo: number;}
MapTypes<{iWillBeANumberOneDay: string, iWillStayTheSame: Function}, StringToNumber> // // gives { iWillBeANumberOneDay: number, iWillStayTheSame: Function }

ts
type StringToNumber = { mapFrom: string; mapTo: number;}
MapTypes<{iWillBeANumberOneDay: string, iWillStayTheSame: Function}, StringToNumber> // // gives { iWillBeANumberOneDay: number, iWillStayTheSame: Function }

View on GitHub

起点

ts
/* _____________ Your Code Here _____________ */
 
type MapTypes<T, R> = any
 
/* _____________ Test Cases _____________ */
 
type cases = [
  Expect<Equal<MapTypes<{ stringToArray: string }, { mapFrom: string, mapTo: [] }>, { stringToArray: [] }>>,
Type 'false' does not satisfy the constraint 'true'.2344Type 'false' does not satisfy the constraint 'true'.
  Expect<Equal<MapTypes<{ stringToNumber: string }, { mapFrom: string, mapTo: number }>, { stringToNumber: number }>>,
Type 'false' does not satisfy the constraint 'true'.2344Type 'false' does not satisfy the constraint 'true'.
  Expect<Equal<MapTypes<{ stringToNumber: string, skipParsingMe: boolean }, { mapFrom: string, mapTo: number }>, { stringToNumber: number, skipParsingMe: boolean }>>,
Type 'false' does not satisfy the constraint 'true'.2344Type 'false' does not satisfy the constraint 'true'.
  Expect<Equal<MapTypes<{ date: string }, { mapFrom: string, mapTo: Date } | { mapFrom: string, mapTo: null }>, { date: null | Date }>>,
Type 'false' does not satisfy the constraint 'true'.2344Type 'false' does not satisfy the constraint 'true'.
  Expect<Equal<MapTypes<{ date: string }, { mapFrom: string, mapTo: Date | null }>, { date: null | Date }>>,
Type 'false' does not satisfy the constraint 'true'.2344Type 'false' does not satisfy the constraint 'true'.
  Expect<Equal<MapTypes<{ fields: Record<string, boolean> }, { mapFrom: Record<string, boolean>, mapTo: string[] }>, { fields: string[] }>>,
Type 'false' does not satisfy the constraint 'true'.2344Type 'false' does not satisfy the constraint 'true'.
  Expect<Equal<MapTypes<{ name: string }, { mapFrom: boolean, mapTo: never }>, { name: string }>>,
Type 'false' does not satisfy the constraint 'true'.2344Type 'false' does not satisfy the constraint 'true'.
  Expect<Equal<MapTypes<{ name: string, date: Date }, { mapFrom: string, mapTo: boolean } | { mapFrom: Date, mapTo: string }>, { name: boolean, date: string }>>,
Type 'false' does not satisfy the constraint 'true'.2344Type 'false' does not satisfy the constraint 'true'.
]

ts
/* _____________ Your Code Here _____________ */
 
type MapTypes<T, R> = any
 
/* _____________ Test Cases _____________ */
 
type cases = [
  Expect<Equal<MapTypes<{ stringToArray: string }, { mapFrom: string, mapTo: [] }>, { stringToArray: [] }>>,
Type 'false' does not satisfy the constraint 'true'.2344Type 'false' does not satisfy the constraint 'true'.
  Expect<Equal<MapTypes<{ stringToNumber: string }, { mapFrom: string, mapTo: number }>, { stringToNumber: number }>>,
Type 'false' does not satisfy the constraint 'true'.2344Type 'false' does not satisfy the constraint 'true'.
  Expect<Equal<MapTypes<{ stringToNumber: string, skipParsingMe: boolean }, { mapFrom: string, mapTo: number }>, { stringToNumber: number, skipParsingMe: boolean }>>,
Type 'false' does not satisfy the constraint 'true'.2344Type 'false' does not satisfy the constraint 'true'.
  Expect<Equal<MapTypes<{ date: string }, { mapFrom: string, mapTo: Date } | { mapFrom: string, mapTo: null }>, { date: null | Date }>>,
Type 'false' does not satisfy the constraint 'true'.2344Type 'false' does not satisfy the constraint 'true'.
  Expect<Equal<MapTypes<{ date: string }, { mapFrom: string, mapTo: Date | null }>, { date: null | Date }>>,
Type 'false' does not satisfy the constraint 'true'.2344Type 'false' does not satisfy the constraint 'true'.
  Expect<Equal<MapTypes<{ fields: Record<string, boolean> }, { mapFrom: Record<string, boolean>, mapTo: string[] }>, { fields: string[] }>>,
Type 'false' does not satisfy the constraint 'true'.2344Type 'false' does not satisfy the constraint 'true'.
  Expect<Equal<MapTypes<{ name: string }, { mapFrom: boolean, mapTo: never }>, { name: string }>>,
Type 'false' does not satisfy the constraint 'true'.2344Type 'false' does not satisfy the constraint 'true'.
  Expect<Equal<MapTypes<{ name: string, date: Date }, { mapFrom: string, mapTo: boolean } | { mapFrom: Date, mapTo: string }>, { name: boolean, date: string }>>,
Type 'false' does not satisfy the constraint 'true'.2344Type 'false' does not satisfy the constraint 'true'.
]

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解决方案

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ts
type MapTypes<T, R> = any
 

ts
type MapTypes<T, R> = any
 

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