类型体操.mts

type PromiseType<T extends Promise<any>> = T extends Promise<infer U> ? U : never;
type Partical<T> = {
  [K in keyof T]?: T[K];
};
type DeepPartial<T> = {
  [K in keyof T]?: T[K] extends object ? DeepPartial<T[K]> : T[K];
};
type MutableDeep<T> = {
  -readonly [K in keyof T]: T[K] extends object ? MutableDeep<T[K]> : T[K];
};
type FuncTypeKeys<T> = {
  [K in keyof T]-?: T[K] extends Function ? K : never;
}[keyof T];

type RequireKeys<T> = {
  [K in keyof T]-?: {} extends Pick<T, K> ? never : K; //这里面的Pick<T, K> 不能换成T[K]
}[keyof T];

type OptionalKeys<T> = {
  [K in keyof T]-?: {} extends Pick<T, K> ? K : never;
}[keyof T];

type PickedByValueType<T, ValueType> = Pick<T, { [K in keyof T]-?: T[K] extends ValueType ? K : never }[keyof T]>;
type ReturnType1<T> = T extends (...arg: any[]) => infer R ? R : any;
type Exclude1<T, K> = T extends K ? never : K;
function isNumber(val: unknown): val is number {
  return typeof val === "number";
}
type ReadOnly2<T> = {
  readonly [K in keyof T]: T[K];
};
type Mutable<T> = {
  -readonly [K in keyof T]: T[K];
};
type Omit2<T, K> = Pick<T, Exclude<keyof T, K>>;
type NonNullable2<T> = T extends null | undefined ? never : T;
type Record2<T extends keyof any, K extends keyof T> = {
  [P in T]: K;
};

type getParams<T> = T extends (...params: any) => infer U ? U : never;
type Pop<T> = T extends [...infer Rest, infer R] ? Rest : never;
type getReturnType<T> = T extends () => infer R ? R : never;

//把字符串重复n次
type RepeatStr<Str extends string, Count extends number, Arr extends Str[] = [], ResStr extends string = ""> = Arr["length"] extends Count ? ResStr : RepeatStr<Str, Count, [Str, ...Arr], `${Str}${ResStr}`>;

//反转字符串
type ReverseStr<Str extends string, Result extends string = ""> = Str extends `${infer First}${infer Rest}` ? ReverseStr<Rest, `${First}${Result}`> : Result;

type ParseQueryString<Str extends string> = Str extends `${infer T}&${infer Rest}` ? MergeParams<parseParams<T>, ParseQueryString<Rest>> : parseParams<Str>;

//将url的query参数解析成对象形式
type MergeParams<One extends object, Other extends object> = {
  [key in keyof One | keyof Other]: key extends keyof One ? (key extends keyof Other ? MergeValue<One[key], Other[key]> : One[key]) : key extends keyof Other ? Other[key] : never;
};

type MergeValue<One, Other> = One extends Other ? One : Other extends unknown[] ? [One, ...Other] : [One, Other];

type parseParams<Str> = Str extends `${infer A}=${infer B}` ? { [key in A]: B } : {};

type ParseQueryStringResult = ParseQueryString<"a=1&a=2&b=2&c=3">;

//拼接两个字符串
type Concat<A extends string, B extends string> = `${A}${B}`;

type Push<array extends unknown[], Item> = [...array, Item];
//分割字符串
type SplitStr<Str extends string, split extends string = "", Arr extends string[] = []> = Str extends `${infer S}${split}${infer Rest}` ? SplitStr<Rest, split, Push<Arr, S>> : Str extends string ? (Str extends "" ? Arr : Push<Arr, Str>) : never;

//获取字符串长度，TS 中元组的长度可以通过['length'] 获取
type getStrLength<Str extends string, Count extends number = 0> = SplitStr<Str>["length"];