TelegramPWA/src/util/iteratees.ts
Alexander Zinchuk 3afcde3217 Initial commit
2021-04-09 14:11:51 +03:00

184 lines
5.0 KiB
TypeScript

type CollectionByKey<Member> = Record<number | string, Member>;
type OrderDirection = 'asc' | 'desc';
interface OrderCallback<T> {
(member: T): any;
}
export function buildCollectionByKey<T extends AnyLiteral>(collection: T[], key: keyof T) {
return collection.reduce((byKey: CollectionByKey<T>, member: T) => {
byKey[member[key]] = member;
return byKey;
}, {});
}
export function mapValues<R extends any, M extends any>(
byKey: CollectionByKey<M>,
callback: (member: M, key: string, index: number, originalByKey: CollectionByKey<M>) => R,
): CollectionByKey<R> {
return Object.keys(byKey).reduce((newByKey: CollectionByKey<R>, key, index) => {
newByKey[key] = callback(byKey[key], key, index, byKey);
return newByKey;
}, {});
}
export function pick<T, K extends keyof T>(object: T, keys: K[]) {
return keys.reduce((result, key) => {
result[key] = object[key];
return result;
}, {} as Pick<T, K>);
}
export function pickTruthy<T, K extends keyof T>(object: T, keys: K[]) {
return keys.reduce((result, key) => {
if (object[key]) {
result[key] = object[key];
}
return result;
}, {} as Pick<T, K>);
}
export function omit<T, K extends keyof T>(object: T, keys: K[]) {
const stringKeys = new Set(keys.map(String));
const savedKeys = Object.keys(object)
.filter((key) => !stringKeys.has(key)) as Array<Exclude<keyof T, K>>;
return pick(object, savedKeys);
}
export function orderBy<T>(
collection: T[],
orderKey: (keyof T) | OrderCallback<T> | ((keyof T) | OrderCallback<T>)[],
mode: OrderDirection | [OrderDirection, OrderDirection] = 'asc',
): T[] {
return collection.sort((a, b) => {
if (Array.isArray(orderKey)) {
const [mode1, mode2] = Array.isArray(mode) ? mode : [mode, mode];
const [orderKey1, orderKey2] = orderKey;
let aValue1;
let bValue1;
if (typeof orderKey1 === 'function') {
aValue1 = orderKey1(a) || 0;
bValue1 = orderKey1(b) || 0;
} else if (typeof orderKey1 === 'string') {
aValue1 = a[orderKey1] || 0;
bValue1 = b[orderKey1] || 0;
}
if (aValue1 !== bValue1) {
return mode1 === 'asc' ? aValue1 - bValue1 : bValue1 - aValue1;
} else {
let aValue2;
let bValue2;
if (typeof orderKey2 === 'function') {
aValue2 = orderKey2(a) || 0;
bValue2 = orderKey2(b) || 0;
} else if (typeof orderKey2 === 'string') {
aValue2 = a[orderKey2] || 0;
bValue2 = b[orderKey2] || 0;
}
return mode2 === 'asc' ? aValue2 - bValue2 : bValue2 - aValue2;
}
}
let aValue;
let bValue;
if (typeof orderKey === 'function') {
aValue = orderKey(a) || 0;
bValue = orderKey(b) || 0;
} else if (typeof orderKey === 'string') {
aValue = a[orderKey] || 0;
bValue = b[orderKey] || 0;
}
return mode === 'asc' ? aValue - bValue : bValue - aValue;
});
}
export function flatten(array: any[]) {
return array.reduce((result, member) => {
if (Array.isArray(member)) {
return result.concat(member);
} else {
result.push(member);
return result;
}
}, []);
}
export function unique<T extends any>(array: T[]): T[] {
return Array.from(new Set(array));
}
export function compact(array: any[]) {
return array.filter(Boolean);
}
export function areSortedArraysEqual(array1: any[], array2: any[]) {
if (array1.length !== array2.length) {
return false;
}
return array1.every((item, i) => item === array2[i]);
}
export function areSortedArraysIntersecting(array1: any[], array2: any[]) {
return array1[0] <= array2[array2.length - 1] && array1[array1.length - 1] >= array2[0];
}
export function findIntersectionWithSet<T>(array: T[], set: Set<T>): T[] {
return array.filter((a) => set.has(a));
}
export function split(array: any[], chunkSize: number) {
const result = [];
for (let i = 0; i < array.length; i += chunkSize) {
result.push(array.slice(i, i + chunkSize));
}
return result;
}
export function cloneDeep<T>(value: T): T {
if (typeof value !== 'object') {
return value;
}
if (Array.isArray(value)) {
return value.map(cloneDeep) as typeof value;
}
return Object.keys(value).reduce((acc, key) => {
acc[key as keyof T] = cloneDeep(value[key as keyof T]);
return acc;
}, {} as T);
}
/**
* Returns the index of the last element in the array where predicate is true, and -1 otherwise.
*
* @param array The source array to search in
* @param predicate find calls predicate once for each element of the array, in descending
* order, until it finds one where predicate returns true. If such an element is found,
* findLastIndex immediately returns that element index. Otherwise, findLastIndex returns -1.
*/
export function findLast<T>(array: Array<T>, predicate: (value: T, index: number, obj: T[]) => boolean): T | undefined {
let cursor = array.length;
while (cursor--) {
if (predicate(array[cursor], cursor, array)) {
return array[cursor];
}
}
return undefined;
}