pattern-collector 🔍

A high-performance pattern collector and ESM import statement analyzer for JavaScript.

🔗 Quick Links:

• 📦 NPM Registry: npmjs.com/package/pattern-collector
• 💻 GitHub Repo: github.com/keshavsoft/pattern-collector
• 📄 Interactive Docs: keshavsoft.github.io/pattern-collector
• ⚙️ Publish Workflow: .github/workflows/npm-publish.yml

📖 Overview

pattern-collector is a zero-dependency, lightweight JavaScript library designed to scan file content and collect substrings that match a specified pattern or regular expression.

It serves as a fast and flexible engine, enabling easy parsing, extraction, and static analysis of source files (such as locating ES Module imports, decorators, function declarations, or other syntactic patterns).

✨ Features

• ⚡ Zero Dependencies: Light, fast, and secure.
• 🧩 Flexible Matching: Collects any patterns by accepting custom global Regular Expressions.
• 📦 ESM Native: Built for modern ES module environments.
• 🏷️ Versioned Under the Hood: Uses an extensible directory-based versioned core.

🚀 Installation

npm install pattern-collector

🛠️ API Reference

default(options)

The default export is a function that collects all occurrences of a pattern in the given text.

Parameters

An options object containing:

• fileContent (string): The raw text or code content to search.
• searchString (RegExp): A regular expression with the global (g) flag to match patterns in the content.

Returns

• Object[]: An array of matches found. If no matches are found, it returns an empty array.
  • match (string): The exact matched substring.
  • line (string): The full line of code containing the match.
  • lineNumber (number): The 1-indexed line number in the source file.

💻 Usage Example

import patternCollector from 'pattern-collector';

const code = `
import { exec } from "child_process";
import dotenv from 'dotenv';
import express from "express";

const PORT = 3000;
`;

// Extract all import statements
const imports = patternCollector({
  fileContent: code,
  searchString: /import\s+[\s\S]*?\s+from\s+['"][^'"]+['"]/g
});

console.log(imports);
/*
Output:
[
  {
    match: 'import { exec } from "child_process"',
    line: 'import { exec } from "child_process";',
    lineNumber: 2
  },
  {
    match: "import dotenv from 'dotenv'",
    line: "import dotenv from 'dotenv';",
    lineNumber: 3
  },
  {
    match: 'import express from "express"',
    line: 'import express from "express";',
    lineNumber: 4
  }
]
*/

⚖️ License

MIT License. Designed with ❤️ by KeshavSoft.