Community Snippets — SaveSnippets

JavaScript Retry Promise with Backoff

Retries a Promise-returning function up to a specified number of times with configurable exponential backoff and optional jitter. Accepts a shouldRetry predicate so you can skip retries on specific error types (e.g. 401 Unauthorized). Returns the resolved value or re-throws the last error after exhausting retries.

#async #retry #promise #utils

@admin 9h ago

JavaScript Queue (Async Task Queue)

A serialised async task queue that executes queued async functions one at a time, in order. Useful for sequencing operations that must not run concurrently (file writes, ordered API mutations, step-by-step wizards). add() returns a Promise that resolves/rejects when that specific task completes.

#async #queue #concurrency #utils

@admin 9h ago

JavaScript Middleware Pipeline

A simple Koa/Express-style middleware runner for client-side use. Middleware functions receive a context object and a next() function — call next() to pass control to the next middleware or skip it to short-circuit the chain. Useful for building plugin systems, request pipelines, and composable validation logic.

#middleware #pipeline #pattern #advanced

@admin 9h ago

JavaScript Deep Equal Comparison

Performs a recursive structural equality check between two values. Handles primitives, arrays, objects, Dates, Maps, Sets, null, and undefined. Faster than JSON.stringify comparison (which ignores undefined and Map/Set), and avoids the false-positive trap of == or Object.is for nested structures.

#comparison #objects #utils

@admin 9h ago

JavaScript Calculate Reading Time

Estimates the reading time of a block of text based on an average adult reading speed (default 200 words per minute). Strips HTML tags before counting to handle rich-text content. Returns the result in minutes, rounded up, so a short article always shows at least "1 min read".

#text #readingtime #utils

@admin 9h ago

JavaScript Generate Initials Avatar (Canvas)

Draws a coloured circular avatar with up to two initials on an HTML5 Canvas and returns it as a data URL. Generates a consistent background colour from the name string so the same user always gets the same colour. Useful as a fallback when a user has no profile photo.

#canvas #avatar #ui #utils

@admin 9h ago

JavaScript Simple State Machine

A lightweight finite state machine that defines valid states and allowed transitions between them. Attempting an invalid transition throws an error. Supports entry/exit hooks per state for side effects. Useful for modelling UI flows (idle → loading → success/error), auth states, and multi-step forms.

#statemachine #pattern #utils

@admin 9h ago

JavaScript String Template Tag — SQL / HTML Sanitiser

A tagged template literal that automatically escapes interpolated values, preventing SQL injection (server-side) or XSS (client-side) from untrusted input. The html tag HTML-encodes values; the sql tag parameterises values and returns a { text, values } tuple ready for a parameterised query driver.

#security #template #xss #sql #tagged-template

@admin 9h ago

JavaScript Worker Pool (Web Workers)

Manages a pool of Web Workers for CPU-intensive tasks (image processing, crypto, parsing). Distributes tasks across available workers using a round-robin strategy and returns a Promise per task. Falls back gracefully to inline execution in environments where workers are unavailable.

#workers #concurrency #performance #advanced

@admin 9h ago

JavaScript IndexedDB Wrapper

A Promise-based wrapper for the IndexedDB API — simplifies the verbose request/onsuccess/onerror pattern into clean async/await calls. Supports get, set, delete, and getAll operations on a named object store. Ideal for storing large client-side datasets, offline data, and blobs that exceed localStorage limits.

#indexeddb #storage #offline #browser

@admin 9h ago

JavaScript Keyboard Shortcut Manager

Registers global keyboard shortcuts with a simple key-combo syntax ("ctrl+k", "meta+shift+p"). Handles modifier keys (ctrl, alt, shift, meta) and prevents default browser behaviour when a shortcut matches. Shortcuts can be unregistered individually or all at once, making it easy to scope shortcuts to page sections or modals.

#keyboard #shortcuts #browser #ui

@admin 9h ago

JavaScript Download File from Client

Programmatically triggers a file download from a Blob, File object, or plain text/JSON string without a server round-trip. Creates a temporary anchor element with a download attribute and revokes the object URL after use to prevent memory leaks. Supports custom filenames and MIME types.

#download #blob #files #browser

@admin 9h ago

JavaScript Long Polling Helper

Implements a long-polling loop that repeatedly calls a fetch endpoint and invokes a callback with the result. Backs off exponentially on errors and stops cleanly when cancelled via the returned stop function. A simple alternative to WebSockets for low-frequency server-push events without SSE support.

#polling #async #http #realtime

@admin 9h ago

JavaScript i18n Minimal Translator

A tiny internationalisation helper that loads a locale dictionary and resolves translation strings by dot-notation key. Supports variable interpolation via {{placeholder}} syntax. Falls back to the key itself when a translation is missing, keeping the UI readable during development. Swap the locale at runtime without a page reload.

#i18n #localization #utils

@admin 9h ago

JavaScript Range Generator

Generates an array of numbers from start to end (inclusive) with an optional step. Supports negative steps for counting down. Covers the most common use case of Array.from({ length: n }, (_, i) => i) with a much cleaner API, and handles arbitrary start/end/step combinations.

#array #range #utils

@admin 9h ago

JavaScript Throttle

Ensures a function is called at most once per specified time interval, no matter how many times the trigger fires. Ideal for scroll listeners, mousemove handlers, and window resize events where you need regular updates but not every single frame.

#throttle #performance #events

@admin 9h ago

JavaScript Deep Clone Object

Creates a true deep copy of any serialisable object or array — nested objects, arrays, dates (as ISO strings). Uses structuredClone when available (modern browsers/Node 17+) and falls back to JSON round-trip for older environments. Does not handle functions, undefined, or circular references.

#clone #objects #utils

@admin 9h ago

JavaScript Deep Merge Objects

Recursively merges two or more objects, combining nested properties rather than overwriting them. Unlike Object.assign or spread, this preserves deep keys from all sources. Useful for merging configuration objects, default settings with user overrides, and API response patching.

#merge #objects #utils

@admin 9h ago