IDGrep

A command-line tool that searches for identifier patterns in JavaScript files using AST parsing.

Context

A "hello world" to familiarize the ULL PL students with AST-based code analysis. It introduces espree, estraverse, commander, regular expressions and typescript. See crguezl PL 24/25 course book, section"Introduction to Espree" for a JS version and more detailed introduction to espree and estraverse.

Setup

1. Install nvm and node or open the repo in a GH codespace
2. Install dependencies:

   npm install

3. Build the project:

   npm run build

4. Run the tool on the example file:

   npm start

Usage

node dist/idgrep.js -p "your_pattern" file1.js file2.js

Development

• npm run build - Compile TypeScript to JavaScript
• npm run dev - Watch mode for development (auto-recompile on changes)
• npm start - Run the compiled version

Project Structure

• src/ - TypeScript source files
  • [index.ts](src/index.ts) - Main CLI application
  • idgrep.ts - Search library
• dist/- Output folder
• dist/hacky.js - Input example
• tsconfig.json - TypeScript configuration with strict type checking
• package.json - Project dependencies and scripts

Exercise for students

Read in detail PL 24/25 course book, section"Introduction to Espree" for a JS version and more detailed introduction to espree and estraverse.