Validates whether a given string is an email using a regular expression.
13 weeks ago
function isValidEmail(email: string): boolean {
const emailRegex = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;
return emailRegex.test(email);
}
Formats a Date object to an ISO string without the time portion.
13 weeks ago
function toISODate(date: Date): string {
return date.toISOString().split("T")[0];
}
Sorts an array of objects by a specified key in ascending or descending order.
13 weeks ago
function sortByKey<T extends Record<string, any>, K extends keyof T>(
array: T[],
key: K,
ascending: boolean = true
): T[] {
return array.sort((a, b) =>
ascending ? (a[key] > b[key] ? 1 : -1) : (a[key] < b[key] ? 1 : -1)
);
}
Wraps a promise with a timeout to reject if it takes too long.
13 weeks ago
function timeoutPromise<T>(promise: Promise<T>, ms: number): Promise<T> {
const timeout = new Promise<never>((_, reject) =>
setTimeout(() => reject(new Error("Timeout exceeded")), ms)
);
return Promise.race([promise, timeout]);
}
Groups an array of objects by a specified key.
13 weeks ago
function groupBy<T extends Record<string, any>, K extends keyof T>(
array: T[],
key: K
): Record<T[K], T[]> {
return array.reduce((acc, item) => {
const groupKey = item[key];
if (!acc[groupKey]) {
acc[groupKey] = [];
}
acc[groupKey].push(item);
return acc;
}, {} as Record<T[K], T[]>);
}
A type-safe utility function to determine if a value is an object.
13 weeks ago
function isObject(value: unknown): value is Record<string, any> {
return value !== null && typeof value === "object" && !Array.isArray(value);
}
Generates a random alphanumeric string of a specified length.
13 weeks ago
function generateRandomString(length: number): string {
const chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
return Array.from({ length }, () =>
chars.charAt(Math.floor(Math.random() * chars.length))
).join("");
}
A recursive function to flatten a deeply nested array.
13 weeks ago
function flattenArray<T>(arr: any[]): T[] {
return arr.reduce(
(flat, item) =>
Array.isArray(item) ? [...flat, ...flattenArray(item)] : [...flat, item],
[] as T[]
);
}
A utility function to capitalize the first letter of a string.
13 weeks ago
function capitalize(str: string): string {
if (!str) return str;
return str.charAt(0).toUpperCase() + str.slice(1);
}
Utility functions to work with TypeScript enums, such as getting all keys or values.
13 weeks ago
enum Colors {
Red = "RED",
Green = "GREEN",
Blue = "BLUE",
}
function getEnumKeys<E>(e: E): (keyof E)[] {
return Object.keys(e).filter((k) => isNaN(Number(k))) as (keyof E)[];
}
function getEnumValues<E>(e: E): E[keyof E][] {
return Object.values(e).filter((v) => typeof v === "string") as E[keyof E][];
}
Implements a strongly typed event emitter for use in applications.
13 weeks ago
type EventMap = Record<string, (...args: any[]) => void>;
class TypedEventEmitter<T extends EventMap> {
private listeners: { [K in keyof T]?: T[K][] } = {};
on<K extends keyof T>(event: K, listener: T[K]): void {
if (!this.listeners[event]) {
this.listeners[event] = [];
}
this.listeners[event]!.push(listener);
}
emit<K extends keyof T>(event: K, ...args: Parameters<T[K]>): void {
this.listeners[event]?.forEach((listener) => listener(...args));
}
}
A custom type guard to check if an object has a specific optional property.
13 weeks ago
function hasProperty<T extends object, K extends PropertyKey>(
obj: T,
key: K
): obj is T & Record<K, unknown> {
return key in obj;
}
Creates a deep copy of an object to ensure no shared references with the original.
13 weeks ago
function deepClone<T>(obj: T): T {
return JSON.parse(JSON.stringify(obj));
}
Prevents a function from being called multiple times in quick succession. Useful for search bars, button clicks, and API requests.
13 weeks ago
function debounce<T extends (...args: any[]) => void>(
func: T,
wait: number
): (...args: Parameters<T>) => void {
let timeout: ReturnType<typeof setTimeout> | null = null;
return (...args: Parameters<T>) => {
if (timeout) clearTimeout(timeout);
timeout = setTimeout(() => {
func(...args);
}, wait);
};
}