@equantic/linq
Version:
eQuantic Linq for JavaScript
177 lines (176 loc) • 7.34 kB
TypeScript
export type IndexedObject = Object & {
[key: string]: any;
};
export interface AbstractType<T> extends Function {
prototype: T;
}
export type Constructor<T> = new (...args: Array<any>) => T;
export type Serializable<T> = Constructor<T> | AbstractType<T>;
export type Primitive = null | undefined | string | number | boolean | symbol | bigint;
export type BrowserNativeObject = Date | FileList | File;
export type FieldValues = Record<string, any>;
/**
* Checks whether T1 can be exactly (mutually) assigned to T2
* @typeParam T1 - type to check
* @typeParam T2 - type to check against
* ```
* IsEqual<string, string> = true
* IsEqual<'foo', 'foo'> = true
* IsEqual<string, number> = false
* IsEqual<string, number> = false
* IsEqual<string, 'foo'> = false
* IsEqual<'foo', string> = false
* IsEqual<'foo' | 'bar', 'foo'> = boolean // 'foo' is assignable, but 'bar' is not (true | false) -> boolean
* ```
*/
export type IsEqual<T1, T2> = T1 extends T2 ? (<G>() => G extends T1 ? 1 : 2) extends <G>() => G extends T2 ? 1 : 2 ? true : false : false;
/**
* Type to query whether an array type T is a tuple type.
* @typeParam T - type which may be an array or tuple
* @example
* ```
* IsTuple<[number]> = true
* IsTuple<number[]> = false
* ```
*/
export type IsTuple<T extends ReadonlyArray<any>> = number extends T['length'] ? false : true;
/**
* Checks whether the type is any
* See {@link https://stackoverflow.com/a/49928360/3406963}
* @typeParam T - type which may be any
* ```
* IsAny<any> = true
* IsAny<string> = false
* ```
*/
export type IsAny<T> = 0 extends 1 & T ? true : false;
/**
* Type which can be used to index an array or tuple type.
*/
export type ArrayKey = number;
/**
* Type which given a tuple type returns its own keys, i.e. only its indices.
* @typeParam T - tuple type
* @example
* ```
* TupleKeys<[number, string]> = '0' | '1'
* ```
*/
export type TupleKeys<T extends ReadonlyArray<any>> = Exclude<keyof T, keyof any[]>;
/**
* Helper function to break apart T1 and check if any are equal to T2
*
* See {@link IsEqual}
*/
type AnyIsEqual<T1, T2> = T1 extends T2 ? (IsEqual<T1, T2> extends true ? true : never) : never;
/**
* Helper type for recursively constructing paths through a type.
* This actually constructs the strings and recurses into nested
* object types.
*
* See {@link Path}
*/
type PathImpl<K extends string | number, V, TraversedTypes> = V extends Primitive | BrowserNativeObject ? `${K}` : true extends AnyIsEqual<TraversedTypes, V> ? `${K}` : `${K}` | `${K}.${PathInternal<V, TraversedTypes | V>}`;
/**
* Helper type for recursively constructing paths through a type.
* This obscures the internal type param TraversedTypes from exported contract.
*
* See {@link Path}
*/
type PathInternal<T, TraversedTypes = T> = T extends ReadonlyArray<infer V> ? IsTuple<T> extends true ? {
[K in TupleKeys<T>]-?: PathImpl<K & string, T[K], TraversedTypes>;
}[TupleKeys<T>] : PathImpl<ArrayKey, V, TraversedTypes> : {
[K in keyof T]-?: PathImpl<K & string, T[K], TraversedTypes>;
}[keyof T];
/**
* Type which eagerly collects all paths through a type
* @typeParam T - type which should be introspected
* @example
* ```
* Path<{foo: {bar: string}}> = 'foo' | 'foo.bar'
* ```
*/
export type Path<T> = T extends any ? PathInternal<T> : never;
/**
* See {@link Path}
*/
export type FieldPath<TFieldValues extends FieldValues> = Path<TFieldValues>;
/**
* Helper type for recursively constructing paths through a type.
* This actually constructs the strings and recurses into nested
* object types.
*
* See {@link ArrayPath}
*/
type ArrayPathImpl<K extends string | number, V, TraversedTypes> = V extends Primitive | BrowserNativeObject ? IsAny<V> extends true ? string : never : V extends ReadonlyArray<infer U> ? U extends Primitive | BrowserNativeObject ? IsAny<V> extends true ? string : never : true extends AnyIsEqual<TraversedTypes, V> ? never : `${K}` | `${K}.${ArrayPathInternal<V, TraversedTypes | V>}` : true extends AnyIsEqual<TraversedTypes, V> ? never : `${K}.${ArrayPathInternal<V, TraversedTypes | V>}`;
/**
* Helper type for recursively constructing paths through a type.
* This obscures the internal type param TraversedTypes from exported contract.
*
* See {@link ArrayPath}
*/
type ArrayPathInternal<T, TraversedTypes = T> = T extends ReadonlyArray<infer V> ? IsTuple<T> extends true ? {
[K in TupleKeys<T>]-?: ArrayPathImpl<K & string, T[K], TraversedTypes>;
}[TupleKeys<T>] : ArrayPathImpl<ArrayKey, V, TraversedTypes> : {
[K in keyof T]-?: ArrayPathImpl<K & string, T[K], TraversedTypes>;
}[keyof T];
/**
* Type which eagerly collects all paths through a type which point to an array
* type.
* @typeParam T - type which should be introspected.
* @example
* ```
* Path<{foo: {bar: string[], baz: number[]}}> = 'foo.bar' | 'foo.baz'
* ```
*/
export type ArrayPath<T> = T extends any ? ArrayPathInternal<T> : never;
/**
* See {@link ArrayPath}
*/
export type FieldArrayPath<TFieldValues extends FieldValues> = ArrayPath<TFieldValues>;
/**
* Type to evaluate the type which the given path points to.
* @typeParam T - deeply nested type which is indexed by the path
* @typeParam P - path into the deeply nested type
* @example
* ```
* PathValue<{foo: {bar: string}}, 'foo.bar'> = string
* PathValue<[number, string], '1'> = string
* ```
*/
export type PathValue<T, P extends Path<T> | ArrayPath<T>> = T extends any ? P extends `${infer K}.${infer R}` ? K extends keyof T ? R extends Path<T[K]> ? PathValue<T[K], R> : never : K extends `${ArrayKey}` ? T extends ReadonlyArray<infer V> ? PathValue<V, R & Path<V>> : never : never : P extends keyof T ? T[P] : P extends `${ArrayKey}` ? T extends ReadonlyArray<infer V> ? V : never : never : never;
/**
* See {@link PathValue}
*/
export type FieldPathValue<TFieldValues extends FieldValues, TFieldPath extends FieldPath<TFieldValues>> = PathValue<TFieldValues, TFieldPath>;
/**
* See {@link PathValue}
*/
export type FieldArrayPathValue<TFieldValues extends FieldValues, TFieldArrayPath extends FieldArrayPath<TFieldValues>> = PathValue<TFieldValues, TFieldArrayPath>;
/**
* Type to evaluate the type which the given paths point to.
* @typeParam TFieldValues - field values which are indexed by the paths
* @typeParam TPath - paths into the deeply nested field values
* @example
* ```
* FieldPathValues<{foo: {bar: string}}, ['foo', 'foo.bar']>
* = [{bar: string}, string]
* ```
*/
export type FieldPathValues<TFieldValues extends FieldValues, TPath extends FieldPath<TFieldValues>[] | readonly FieldPath<TFieldValues>[]> = {} & {
[K in keyof TPath]: FieldPathValue<TFieldValues, TPath[K] & FieldPath<TFieldValues>>;
};
/**
* Type which eagerly collects all paths through a fieldType that matches a give type
* @typeParam TFieldValues - field values which are indexed by the paths
* @typeParam TValue - the value you want to match into each type
* @example
* ```typescript
* FieldPathByValue<{foo: {bar: number}, baz: number, bar: string}, number>
* = 'foo.bar' | 'baz'
* ```
*/
export type FieldPathByValue<TFieldValues extends FieldValues, TValue> = {
[Key in FieldPath<TFieldValues>]: FieldPathValue<TFieldValues, Key> extends TValue ? Key : never;
}[FieldPath<TFieldValues>];
export {};