JS Tutorials And Tech Blog

Hi, I'm Hamza, a lead software engineer specializing in everything JavaScript. I write the tutorials, code snippets, and tech notes here.

JavascriptHacker is where I write up what I'm building and learning: practical tutorials and short code snippets across web development, Node, React, web scraping, and automation.

I also cover AI coding tools and the tech news worth paying attention to. Everything here is the kind of thing I'd actually want to read.

[read the blog][browse snippets]

Hamza Rahman

Learner | Developer

Lead Developer - building products

Pakistan🇵🇰

github.com/yum72

function fixBug(bug) {
  return Math.random() < 0.5 ? bug : moreBugs  // progress
}

function estimate(task) {
  return task.guess * 3  // still wildly optimistic
}

const coffee = await brew()
if (!coffee) throw new Error('cannot code, send help')

function understand(legacyCode) {
  return undefined  // nobody actually knows
}

while (it.works) { dont.touch(it) }
const fix = stackOverflow.copy().paste()  // it works now

function review(pr) {
  return Math.random() > 0.1 ? 'LGTM' : 'add tests'  // brave
}

git commit -m "final_v2_FINAL_actually_use_this_one"

function fixBug(bug) {
  return Math.random() < 0.5 ? bug : moreBugs  // progress
}

function estimate(task) {
  return task.guess * 3  // still wildly optimistic
}

const coffee = await brew()
if (!coffee) throw new Error('cannot code, send help')

function understand(legacyCode) {
  return undefined  // nobody actually knows
}

while (it.works) { dont.touch(it) }
const fix = stackOverflow.copy().paste()  // it works now

function review(pr) {
  return Math.random() > 0.1 ? 'LGTM' : 'add tests'  // brave
}

git commit -m "final_v2_FINAL_actually_use_this_one"

function fixBug(bug) {
  return Math.random() < 0.5 ? bug : moreBugs  // progress
}

function estimate(task) {
  return task.guess * 3  // still wildly optimistic
}

const coffee = await brew()
if (!coffee) throw new Error('cannot code, send help')

function understand(legacyCode) {
  return undefined  // nobody actually knows
}

while (it.works) { dont.touch(it) }
const fix = stackOverflow.copy().paste()  // it works now

function review(pr) {
  return Math.random() > 0.1 ? 'LGTM' : 'add tests'  // brave
}

git commit -m "final_v2_FINAL_actually_use_this_one"

function fixBug(bug) {
  return Math.random() < 0.5 ? bug : moreBugs  // progress
}

function estimate(task) {
  return task.guess * 3  // still wildly optimistic
}

const coffee = await brew()
if (!coffee) throw new Error('cannot code, send help')

function understand(legacyCode) {
  return undefined  // nobody actually knows
}

while (it.works) { dont.touch(it) }
const fix = stackOverflow.copy().paste()  // it works now

function review(pr) {
  return Math.random() > 0.1 ? 'LGTM' : 'add tests'  // brave
}

git commit -m "final_v2_FINAL_actually_use_this_one"

function fixBug(bug) {
  return Math.random() < 0.5 ? bug : moreBugs  // progress
}

function estimate(task) {
  return task.guess * 3  // still wildly optimistic
}

const coffee = await brew()
if (!coffee) throw new Error('cannot code, send help')

function understand(legacyCode) {
  return undefined  // nobody actually knows
}

while (it.works) { dont.touch(it) }
const fix = stackOverflow.copy().paste()  // it works now

function review(pr) {
  return Math.random() > 0.1 ? 'LGTM' : 'add tests'  // brave
}

git commit -m "final_v2_FINAL_actually_use_this_one"

function fixBug(bug) {
  return Math.random() < 0.5 ? bug : moreBugs  // progress
}

function estimate(task) {
  return task.guess * 3  // still wildly optimistic
}

const coffee = await brew()
if (!coffee) throw new Error('cannot code, send help')

function understand(legacyCode) {
  return undefined  // nobody actually knows
}

while (it.works) { dont.touch(it) }
const fix = stackOverflow.copy().paste()  // it works now

function review(pr) {
  return Math.random() > 0.1 ? 'LGTM' : 'add tests'  // brave
}

git commit -m "final_v2_FINAL_actually_use_this_one"

function fixBug(bug) {
  return Math.random() < 0.5 ? bug : moreBugs  // progress
}

function estimate(task) {
  return task.guess * 3  // still wildly optimistic
}

const coffee = await brew()
if (!coffee) throw new Error('cannot code, send help')

function understand(legacyCode) {
  return undefined  // nobody actually knows
}

while (it.works) { dont.touch(it) }
const fix = stackOverflow.copy().paste()  // it works now

function review(pr) {
  return Math.random() > 0.1 ? 'LGTM' : 'add tests'  // brave
}

git commit -m "final_v2_FINAL_actually_use_this_one"

function fixBug(bug) {
  return Math.random() < 0.5 ? bug : moreBugs  // progress
}

function estimate(task) {
  return task.guess * 3  // still wildly optimistic
}

const coffee = await brew()
if (!coffee) throw new Error('cannot code, send help')

function understand(legacyCode) {
  return undefined  // nobody actually knows
}

while (it.works) { dont.touch(it) }
const fix = stackOverflow.copy().paste()  // it works now

function review(pr) {
  return Math.random() > 0.1 ? 'LGTM' : 'add tests'  // brave
}

git commit -m "final_v2_FINAL_actually_use_this_one"

function fixBug(bug) {
  return Math.random() < 0.5 ? bug : moreBugs  // progress
}

function estimate(task) {
  return task.guess * 3  // still wildly optimistic
}

const coffee = await brew()
if (!coffee) throw new Error('cannot code, send help')

function understand(legacyCode) {
  return undefined  // nobody actually knows
}

while (it.works) { dont.touch(it) }
const fix = stackOverflow.copy().paste()  // it works now

function review(pr) {
  return Math.random() > 0.1 ? 'LGTM' : 'add tests'  // brave
}

git commit -m "final_v2_FINAL_actually_use_this_one"

function fixBug(bug) {
  return Math.random() < 0.5 ? bug : moreBugs  // progress
}

function estimate(task) {
  return task.guess * 3  // still wildly optimistic
}

const coffee = await brew()
if (!coffee) throw new Error('cannot code, send help')

function understand(legacyCode) {
  return undefined  // nobody actually knows
}

while (it.works) { dont.touch(it) }
const fix = stackOverflow.copy().paste()  // it works now

function review(pr) {
  return Math.random() > 0.1 ? 'LGTM' : 'add tests'  // brave
}

git commit -m "final_v2_FINAL_actually_use_this_one"

function fixBug(bug) {
  return Math.random() < 0.5 ? bug : moreBugs  // progress
}

function estimate(task) {
  return task.guess * 3  // still wildly optimistic
}

const coffee = await brew()
if (!coffee) throw new Error('cannot code, send help')

function understand(legacyCode) {
  return undefined  // nobody actually knows
}

while (it.works) { dont.touch(it) }
const fix = stackOverflow.copy().paste()  // it works now

function review(pr) {
  return Math.random() > 0.1 ? 'LGTM' : 'add tests'  // brave
}

git commit -m "final_v2_FINAL_actually_use_this_one"

function fixBug(bug) {
  return Math.random() < 0.5 ? bug : moreBugs  // progress
}

function estimate(task) {
  return task.guess * 3  // still wildly optimistic
}

const coffee = await brew()
if (!coffee) throw new Error('cannot code, send help')

function understand(legacyCode) {
  return undefined  // nobody actually knows
}

while (it.works) { dont.touch(it) }
const fix = stackOverflow.copy().paste()  // it works now

function review(pr) {
  return Math.random() > 0.1 ? 'LGTM' : 'add tests'  // brave
}

git commit -m "final_v2_FINAL_actually_use_this_one"

function fixBug(bug) {
  return Math.random() < 0.5 ? bug : moreBugs  // progress
}

function estimate(task) {
  return task.guess * 3  // still wildly optimistic
}

const coffee = await brew()
if (!coffee) throw new Error('cannot code, send help')

function understand(legacyCode) {
  return undefined  // nobody actually knows
}

while (it.works) { dont.touch(it) }
const fix = stackOverflow.copy().paste()  // it works now

function review(pr) {
  return Math.random() > 0.1 ? 'LGTM' : 'add tests'  // brave
}

git commit -m "final_v2_FINAL_actually_use_this_one"

function fixBug(bug) {
  return Math.random() < 0.5 ? bug : moreBugs  // progress
}

function estimate(task) {
  return task.guess * 3  // still wildly optimistic
}

const coffee = await brew()
if (!coffee) throw new Error('cannot code, send help')

function understand(legacyCode) {
  return undefined  // nobody actually knows
}

while (it.works) { dont.touch(it) }
const fix = stackOverflow.copy().paste()  // it works now

function review(pr) {
  return Math.random() > 0.1 ? 'LGTM' : 'add tests'  // brave
}

git commit -m "final_v2_FINAL_actually_use_this_one"

function fixBug(bug) {
  return Math.random() < 0.5 ? bug : moreBugs  // progress
}

function estimate(task) {
  return task.guess * 3  // still wildly optimistic
}

const coffee = await brew()
if (!coffee) throw new Error('cannot code, send help')

function understand(legacyCode) {
  return undefined  // nobody actually knows
}

while (it.works) { dont.touch(it) }
const fix = stackOverflow.copy().paste()  // it works now

function review(pr) {
  return Math.random() > 0.1 ? 'LGTM' : 'add tests'  // brave
}

git commit -m "final_v2_FINAL_actually_use_this_one"

function fixBug(bug) {
  return Math.random() < 0.5 ? bug : moreBugs  // progress
}

function estimate(task) {
  return task.guess * 3  // still wildly optimistic
}

const coffee = await brew()
if (!coffee) throw new Error('cannot code, send help')

function understand(legacyCode) {
  return undefined  // nobody actually knows
}

while (it.works) { dont.touch(it) }
const fix = stackOverflow.copy().paste()  // it works now

function review(pr) {
  return Math.random() > 0.1 ? 'LGTM' : 'add tests'  // brave
}

git commit -m "final_v2_FINAL_actually_use_this_one"

Published on
June 26, 2026
Cheerio vs node-html-parser
Cheerio vs node-html-parser for parsing HTML in Node.js: node-html-parser is lighter and faster, Cheerio has a fuller jQuery-style API. How to choose between them.
web-scraping nodejs cheerio
Published on
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Cheerio vs Puppeteer: which to use for scraping
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web-scraping nodejs cheerio puppeteer
Published on
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Building a RAG System with MongoDB and Node.js
Build a RAG system in Node.js using MongoDB text search. A good fit when you already run MongoDB and need keyword retrieval without a separate vector database.
nodejs mongodb rag text-search database
Published on
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Building a RAG System with Pinecone and Node.js
Build a RAG system in Node.js with Pinecone and OpenAI embeddings. Semantic search that matches on meaning, for large document collections that outgrow keyword search.
nodejs pinecone vector-database rag semantic-search
Published on
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Check if a string is alphanumeric in JavaScript
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javascript snippets string
Published on
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Force an LLM to return JSON in JavaScript
Return schema-shaped JSON from an LLM in JavaScript using OpenAI structured outputs instead of fragile JSON parsing.
javascript snippets llm openai json
Published on
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The nullish coalescing operator (??) in JavaScript
What the double question mark (??) means in JavaScript: the nullish coalescing operator, how it differs from ||, and the ??= assignment shorthand.
javascript snippets tips
Published on
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LangChain JS agent with a custom tool
Create a small LangChain JavaScript agent with one custom tool using createAgent, tool, and Zod.
javascript snippets langchain agents llm
Published on
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OpenAI function calling JavaScript example
Minimal OpenAI function calling example in JavaScript using a local tool and the Responses API.
javascript snippets openai llm agents
Published on
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OpenAI structured outputs with Zod in JavaScript
Use OpenAI structured outputs with a Zod schema to get typed JSON back from an LLM in JavaScript.
javascript snippets openai llm zod
Published on
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Vercel AI SDK tool calling example
Minimal Vercel AI SDK tool calling example using generateText, tool, stepCountIs, and Zod.
javascript snippets ai-sdk llm agents
Published on
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AI Coding Benchmark Leaderboard: Cursor + DeepSWE
A combined AI coding benchmark leaderboard merging CursorBench and DeepSWE. See which model wins on correctness versus cost: Fable 5, GPT-5.5, Claude, and more.
ai llm benchmarks coding-agents cursor
Published on
November 3, 2025
Deploy Next.js SSR to Cloudflare Workers with GitHub Actions
I tried to deploy my Next.js SSR app and hit the usual snags (Pages 404s, works-on-my-machine). Here’s the simple CI/CD flow I shipped with Cloudflare Workers + GitHub Actions.
nextjs cloudflare github-actions ssr cicd
Published on
November 15, 2024
Build a RAG System with Node.js and OpenAI - No Database Required
Build a simple RAG system in Node.js with OpenAI and plain text files. No vector database, no embeddings: pass docs into the model and get answers.
nodejs openai rag chatgpt api javascript express
Published on
September 10, 2024
Nextjs Link onClick: Run Code, Redirect, and Handle Forms
How to use the onClick prop on the Next.js Link component to run code before navigation, redirect programmatically, and use preventDefault, with App Router and Pages Router examples in JavaScript and TypeScript.
nextjs react routing
Published on
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How to Train Your Team on KPI Software Tools
Learn practical strategies to effectively train your team on KPI software tools, enhancing their productivity and aligning them with organizational goals.
tech
Published on
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RFID Technology
RFID technology or Radio Frequency Identification has revolutionized the way businesses track and manage inventory.
tech
Published on
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Understanding !! in JavaScript - A Simple Guide
A practical guide to what the double exclamation mark (!!) does in JavaScript, how it differs from Boolean() and the ?? operator, with real examples.
javascript tips
Published on
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Javascript add property to object
Add a property to an object in JavaScript with dot notation, square brackets, the spread operator, and Object.assign. Plus dynamic keys, conditional properties, nested objects, adding several at once, and TypeScript.
javascript snippets object
Published on
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Javascript random alphanumeric string of length n
How to create a random alphanumeric string of a certain length in javascript, with a simple helper and a more secure crypto-based version.
javascript snippets helper
Published on
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Javascript: check if an array contains a string
How to check if a JavaScript array contains a string with includes, some, and indexOf, and how to check if a string contains any element from an array.
javascript snippets array
Published on
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Web scraping with Node, Axios and Cheerio
Web scraping tutorial with Node.js using Axios and Cheerio. Fetch a page, select data with Cheerio CSS selectors, filter it, handle pagination, and save the results to a CSV file.
web-scraping nodejs axios cheerio