GuilloOme/background.js

## background.js
(function() {
    'use strict';

    // keep track of all the opened tab
    let tabs = {};

    // Get all existing tabs
    chrome.tabs.query({}, function(results) {
        results.forEach(function(tab) {
            tabs[tab.id] = tab;
        });
    });

    // Create tab event listeners
    function onUpdatedListener(tabId, changeInfo, tab) {
        tabs[tab.id] = tab;
    }

    function onRemovedListener(tabId) {
        delete tabs[tabId];
    }

    /**
     * if the request url differ from the current tab url block it
     * @param details
     * @return {{redirectUrl: string}}
     */
    function onBeforeRequestListener(details) {
        let currentTab = tabs[details.tabId];

        if (currentTab.url.startsWith('http') && _compareUrls(details.url, currentTab.url)) {
            console.warn(`Navigation to ${details.url} blocked.`);
            chrome.tabs.executeScript(details.tabId, {file: 'content.js'}, function() {
                chrome.tabs.sendMessage(details.tabId, {url: details.url});
            });
            return {redirectUrl: 'javascript:void(0)'};
        }
    }

    // Subscribe to tab events to track opened tabs
    chrome.tabs.onUpdated.addListener(onUpdatedListener);
    chrome.tabs.onRemoved.addListener(onRemovedListener);

    chrome.webRequest.onBeforeRequest.addListener(onBeforeRequestListener, {
        urls: ['<all_urls>'],
        types: ['main_frame', 'sub_frame'], // only watching for "frame" type request
    }, ['blocking']);

    /**
     * compare 2 urls based on there href form WITHOUT the hash part
     * @param {string} url1
     * @param {string} url2
     * @return {boolean}
     * @private
     */
    function _compareUrls(url1, url2) {
        let cleanedUrl1 = new URL(url1),
            cleanedUrl2 = new URL(url2);

        cleanedUrl1.hash = '';
        cleanedUrl2.hash = '';

        return cleanedUrl1.href !== cleanedUrl2.href;
    }

})();

## content.js
(function() {
    'use strict';
    // transmitting url received from the background page to the page
    chrome.runtime.onMessage.addListener(function(msg) {
        window.postMessage({type: 'NavigationBlocked', url: msg.url}, '*');
    });
})();

## example_navigation_away_test_case.html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>test</title>
</head>
<body>
<a href="page1.html">page1 (should be blocked)</a>
<br/><br/>
<a href="javascript:window.location = 'page2.html'">page2 (should be blocked)</a>
<script>
    window.onbeforeunload = function() {
        console.warn('Page: beforeunload');
    };

    window.onunload = function() {
        console.err('Page : unload');
    };

    window.addEventListener('message', function(event) {
        if (event.data.type && event.data.type === 'NavigationBlocked' && event.data.url) {
            console.info('Got url from extension: ' + event.data.url); // since we are in the page, we can retrieve the url the way, we want
        }
    });
</script>
</body>
</html>

## index.js
(function() {
  'use strict';
  const puppeteer = require('puppeteer');

  const browser = await puppeteer.launch({
    headless: false,
    args: {
      '--load-extension=/path/to/chrome_extension/',
      '--disable-extensions-except=path/to/chrome_extension/',
    }
  });

  const page = await browser.newPage();
  await page.goto('https://mypage.lan/example_navigation_away_test_case.html');
  await page.click('a');
  console.log(await page.content());
  await page.screenshot({path: 'screenshot.png'});

  await browser.close();

})();

## manifest.json
{
  "manifest_version": 2,
  "name": "Puppeteer workaround - Navigation blocker",
  "version": "1.0",
  "permissions": [
    "webRequest",
    "*://*/*",
    "webRequestBlocking",
    "tabs"
  ],
  "background": {
    "persistent": true,
    "scripts": [
      "background.js"
    ]
  }
}
	(function() {
	'use strict';

	// keep track of all the opened tab
	let tabs = {};

	// Get all existing tabs
	chrome.tabs.query({}, function(results) {
	results.forEach(function(tab) {
	tabs[tab.id] = tab;
	});
	});

	// Create tab event listeners
	function onUpdatedListener(tabId, changeInfo, tab) {
	tabs[tab.id] = tab;
	}

	function onRemovedListener(tabId) {
	delete tabs[tabId];
	}

	/**
	* if the request url differ from the current tab url block it
	* @param details
	* @return {{redirectUrl: string}}
	*/
	function onBeforeRequestListener(details) {
	let currentTab = tabs[details.tabId];

	if (currentTab.url.startsWith('http') && _compareUrls(details.url, currentTab.url)) {
	console.warn(`Navigation to ${details.url} blocked.`);
	chrome.tabs.executeScript(details.tabId, {file: 'content.js'}, function() {
	chrome.tabs.sendMessage(details.tabId, {url: details.url});
	});
	return {redirectUrl: 'javascript:void(0)'};
	}
	}

	// Subscribe to tab events to track opened tabs
	chrome.tabs.onUpdated.addListener(onUpdatedListener);
	chrome.tabs.onRemoved.addListener(onRemovedListener);

	chrome.webRequest.onBeforeRequest.addListener(onBeforeRequestListener, {
	urls: ['<all_urls>'],
	types: ['main_frame', 'sub_frame'], // only watching for "frame" type request
	}, ['blocking']);

	/**
	* compare 2 urls based on there href form WITHOUT the hash part
	* @param {string} url1
	* @param {string} url2
	* @return {boolean}
	* @private
	*/
	function _compareUrls(url1, url2) {
	let cleanedUrl1 = new URL(url1),
	cleanedUrl2 = new URL(url2);

	cleanedUrl1.hash = '';
	cleanedUrl2.hash = '';

	return cleanedUrl1.href !== cleanedUrl2.href;
	}

	})();
	(function() {
	'use strict';
	// transmitting url received from the background page to the page
	chrome.runtime.onMessage.addListener(function(msg) {
	window.postMessage({type: 'NavigationBlocked', url: msg.url}, '*');
	});
	})();
	<!DOCTYPE html>
	<html lang="en">
	<head>
	<meta charset="UTF-8">
	<title>test</title>
	</head>
	<body>
	<a href="page1.html">page1 (should be blocked)</a>
	<br/><br/>
	<a href="javascript:window.location = 'page2.html'">page2 (should be blocked)</a>
	<script>
	window.onbeforeunload = function() {
	console.warn('Page: beforeunload');
	};

	window.onunload = function() {
	console.err('Page : unload');
	};

	window.addEventListener('message', function(event) {
	if (event.data.type && event.data.type === 'NavigationBlocked' && event.data.url) {
	console.info('Got url from extension: ' + event.data.url); // since we are in the page, we can retrieve the url the way, we want
	}
	});
	</script>
	</body>
	</html>
	(function() {
	'use strict';
	const puppeteer = require('puppeteer');

	const browser = await puppeteer.launch({
	headless: false,
	args: {
	'--load-extension=/path/to/chrome_extension/',
	'--disable-extensions-except=path/to/chrome_extension/',
	}
	});

	const page = await browser.newPage();
	await page.goto('https://mypage.lan/example_navigation_away_test_case.html');
	await page.click('a');
	console.log(await page.content());
	await page.screenshot({path: 'screenshot.png'});

	await browser.close();

	})();
	{
	"manifest_version": 2,
	"name": "Puppeteer workaround - Navigation blocker",
	"version": "1.0",
	"permissions": [
	"webRequest",
	":///*",
	"webRequestBlocking",
	"tabs"
	],
	"background": {
	"persistent": true,
	"scripts": [
	"background.js"
	]
	}
	}