feat : lighthouse service added

controllers/lighthouse.js

@@ -0,0 +1,119 @@
+const argv = require('yargs').argv;
+const url = require('url');
+const fs = require('fs');
+const glob = require('glob');
+const path = require('path');
+
+
+const launchChromeAndRunLighthouse = async (url) => {
+    const lighthouse = (await import('lighthouse')).default;
+    const chromeLauncher = await import('chrome-launcher');
+    try {
+        const chrome = await chromeLauncher.launch();
+        const opts = {
+            port: chrome.port
+        };
+
+        const results = await lighthouse(url, opts);
+
+        await chrome.kill();
+
+        return {
+            js: results.lhr,
+            json: results.report
+        };
+    } catch (error) {
+        console.error('Error:', error);
+        throw error; // Propagate the error
+    }
+};
+
+const getContents = (pathStr) => {
+	const output = fs.readFileSync(pathStr, 'utf8', (err, results) => {
+		return results;
+	});
+	return JSON.parse(output);
+};
+
+const compareReports = (from, to) => {
+	const metricFilter = [
+		'first-contentful-paint',
+		'first-meaningful-paint',
+		'speed-index',
+		'estimated-input-latency',
+		'total-blocking-time',
+		'max-potential-fid',
+		'time-to-first-byte',
+		'first-cpu-idle',
+		'interactive'
+	]
+
+	const calcPercentageDiff = (from, to) => {
+		const per = ((to - from) / from) * 100;
+		return Math.round(per * 100) / 100;
+	};
+
+	for(let auditObj in from['audits']) {
+		if(metricFilter.includes(auditObj)) {
+			const percentageDiff = calcPercentageDiff(
+				from['audits'][auditObj].numericValue,
+				to['audits'][auditObj].numericValue
+			);
+
+			let logColor = '\x1b[37m';
+			const log = (() => {
+				if(Math.sign(percentageDiff) === 1) {
+					logColor = "\x1b[31m";
+					return `${percentageDiff.toString().replace('-','') + '%'} slower`;
+				}
+				else if(Math.sign(percentageDiff) === 0) {
+					return 'unchanged';
+				}
+				else {
+					logColor = "\x1b[32m";
+					return `${percentageDiff.toString().replace('-','') + '%'} faster`;
+				}
+			})();
+			console.log(logColor, `${from['audits'][auditObj].title} is ${log}`);
+		}
+	}
+}
+
+
+module.exports.launchChromeAndRunLighthouse = async () => {
+   // const urlObj = new URL(argv.url);
+	let dirName = "report";
+	// if(urlObj.pathname !== '/') {
+	// 	dirName = dirName + urlObj.pathname.replace(/\//g,'_');
+	// }
+
+	if(!fs.existsSync(dirName)) {
+	    fs.mkdirSync(dirName);
+	}
+
+    const results  = await launchChromeAndRunLighthouse("https://www.smashingmagazine.com/2020/09/introduction-running-lighthouse-programmatically/");
+
+    const prevReports = glob(`${dirName}/*.json`, {
+        sync: true
+    });
+
+    if(prevReports.length) {
+        dates = [];
+        for(report in prevReports) {
+            dates.push(new Date(path.parse(prevReports[report]).name.replace(/_/g, ':')));
+        }
+        const max = dates.reduce(function(a, b) {
+            return Math.max(a, b);
+        });
+        const recentReport = new Date(max).toISOString();
+
+        const recentReportContents = getContents(dirName + '/' + recentReport.replace(/:/g, '_') + '.json');
+
+        compareReports(recentReportContents, results.js);
+    }
+
+    fs.writeFile(`${dirName}/${results.js['fetchTime'].replace(/:/g, '_')}.json`, results.json, (err) => {
+        if (err) throw err;
+    });
+
+}