Node script to extract unique domains from a `*.har` file.

[1] README.md

How to use

To use this Node script:

1. Save the contents of the script in a file named har-domain-parser.cjs.

2. Place your trace.har file in the same directory as the script file.

3. Then run the script using the command line.

node har-domain-parser.cjs

When it has finished running, it will create another file in the same directory named domains.txt.

[2] har-domain-parser.cjs

const { join } = require('path');
const { readFileSync, writeFileSync } = require('fs');

// ==========
// Constants.
// ==========

const FILE_NAME_TEXT = 'domains.txt';
const FILE_NAME_TRACE = 'trace.har';

// =========
// Encoding.
// =========

const encoding = 'utf8';
const options = { encoding };

// ===============
// Get file paths.
// ===============

const pathForFileInput = join(__dirname, FILE_NAME_TRACE);
const pathForFileOutput = join(__dirname, FILE_NAME_TEXT);

// ===============
// Get input text.
// ===============

const textForFileInput = readFileSync(pathForFileInput, options);
const jsonForFileInput = JSON.parse(textForFileInput);

// ===================
// Helper: add domain.
// ===================

const domainSet = new Set();

const addDomain = (value = '') => {
  // Get domain.
  let domain = value.split('://')[1] || '';
  domain = domain.split('/')[0] || '';

  // Domain exists?
  if (domain) {
    // Add to set.
    domainSet.add(domain);
  }
};

// ================================================
// Helper: recursively parse `*.parent.callFrames`.
// ================================================

const parseCallFrames = (obj = {}) => {
  // Loop through call frames.
  obj.callFrames?.forEach(({ url }) => {
    // Add domains.
    addDomain(url);
  });

  // Parent exists?
  if (obj.parent) {
    // Recursion.
    parseCallFrames(obj.parent)
  }
};

// =====================
// Loop through entries.
// =====================

jsonForFileInput.log.entries.forEach((entry) => {
  // ========================
  // Loop through initiators.
  // ========================

  // Add domains.
  addDomain(entry._initiator.url);
  addDomain(entry.request.url);

  // Parse call frames.
  parseCallFrames(entry._initiator.stack);
});

// ================
// Get output text.
// ================

const domainArray = Array.from(domainSet).sort();
const textForFileOutput = domainArray.join('\n');

// ==============
// Write to file.
// ==============

writeFileSync(pathForFileOutput, textForFileOutput, options);

// ===============
// Log completion.
// ===============

global.console.clear();
global.console.log(`Parsing complete. Domains written to file:\n\n${pathForFileOutput}\n`);