pattern-collector

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

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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).

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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.

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Installation

npm install pattern-collector

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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

• (string[]): An array of matches found. If no matches are found, it returns an empty array.

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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:
[
  'import { exec } from "child_process"',
  "import dotenv from 'dotenv'",
  'import express from "express"'
]
*/

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License

MIT License. Designed with by KeshavSoft.