Fix profiling for 'ui5 serve'

Author: RandomByte

bin/ui5.cjs

@@ -90,12 +90,19 @@ const ui5 = {
 	},
 
 	async invokeCLI(pkg) {
+		let profile;
 		if (process.env.UI5_CLI_PROFILE) {
-			const profile = await import("../lib/utils/profile.js");
+			profile = await import("../lib/utils/profile.js");
 			await profile.start();
 		}
 		const {default: cli} = await import("../lib/cli/cli.js");
-		await cli(pkg);
+		const {command} = await cli(pkg);
+
+		// Stop profiling after CLI finished execution
+		// Except for "serve" command, which continues running and only stops on sigint (see profile.js)
+		if (profile && command !== "serve") {
+			await profile.stop();
+		}
 	},
 
 	async main() {
@@ -105,8 +112,7 @@ const ui5 = {
 		} else {
 			const localInstallationInvoked = await ui5.invokeLocalInstallation(pkg);
 			if (!localInstallationInvoked) {
-				const exitCode = await ui5.invokeCLI(pkg);
-				process.exit(exitCode);
+				await ui5.invokeCLI(pkg);
 			}
 		}
 	}

lib/cli/base.js

@@ -135,5 +135,6 @@ export default function(cli) {
 				process.stderr.write(chalk.dim(`See 'ui5 --help'`));
 				process.stderr.write("\n");
 			}
+			process.exit(1);
 		});
 }

lib/cli/cli.js

@@ -68,20 +68,8 @@ export default async (pkg) => {
 	// Format terminal output to full available width
 	cli.wrap(cli.terminalWidth());
 
-	let exitCode = 0;
-	try {
-		// Call parse to run yargs
-		await cli.parse();
-	} catch (err) {
-		// Error is already handled via .fail callback in ./base.js
-		exitCode = 1;
-	} finally {
-		// Stop profiling after CLI finished execution
-		if (process.env.UI5_CLI_PROFILE) {
-			const profile = await import("../utils/profile.js");
-			await profile.stop();
-		}
-	}
-
-	return exitCode;
+	const {_} = await cli.argv;
+	return {
+		command: _[0]
+	};
 };

lib/utils/profile.js

@@ -2,6 +2,7 @@ import {writeFile} from "node:fs/promises";
 import {Session} from "node:inspector";
 
 let session;
+let processSignals;
 
 export async function start() {
 	if (session) {
@@ -11,25 +12,44 @@ export async function start() {
 	session.connect();
 	await new Promise((resolve) => {
 		session.post("Profiler.enable", () => {
+			console.log(`Recording CPU profile...`);
 			session.post("Profiler.start", () => {
+				processSignals = registerSigHooks();
 				resolve();
 			});
 		});
 	});
 }
 
 async function writeProfile(profile) {
-	const d = new Date();
-	const timestamp =
-		`${d.getFullYear()}-${d.getMonth()+1}-${d.getDate()}_${d.getHours()}-${d.getMinutes()}-${d.getSeconds()}`;
+	const formatter = new Intl.DateTimeFormat("en-GB", {
+		year: "numeric",
+		month: "2-digit",
+		day: "2-digit",
+		hour: "2-digit",
+		minute: "2-digit",
+		second: "2-digit",
+	});
+	const dateParts = Object.create(null);
+	const parts = formatter.formatToParts(new Date());
+	parts.forEach((p) => {
+		dateParts[p.type] = p.value;
+	});
 
-	await writeFile(`./ui5_${timestamp}.cpuprofile`, JSON.stringify(profile));
+	const fileName = `./ui5_${dateParts.year}-${dateParts.month}-${dateParts.day}_` +
+		`${dateParts.hour}-${dateParts.minute}-${dateParts.second}.cpuprofile`;
+	console.log(`\nSaving CPU profile to ${fileName}...`);
+	await writeFile(fileName, JSON.stringify(profile));
 }
 
 export async function stop() {
 	if (!session) {
 		return;
 	}
+	if (processSignals) {
+		deregisterSigHooks(processSignals);
+		processSignals = null;
+	}
 	const profile = await new Promise((resolve) => {
 		session.post("Profiler.stop", (err, {profile}) => {
 			if (err) {
@@ -38,8 +58,38 @@ export async function stop() {
 				resolve(profile);
 			}
 		});
+		session = null;
 	});
 	if (profile) {
 		await writeProfile(profile);
 	}
 }
+
+function registerSigHooks() {
+	function createListener(exitCode) {
+		return function() {
+			// Gracefully end profiling, then exit
+			stop().then(() => {
+				process.exit(exitCode);
+			});
+		};
+	}
+
+	const processSignals = {
+		"SIGHUP": createListener(128 + 1),
+		"SIGINT": createListener(128 + 2),
+		"SIGTERM": createListener(128 + 15),
+		"SIGBREAK": createListener(128 + 21)
+	};
+
+	for (const signal of Object.keys(processSignals)) {
+		process.on(signal, processSignals[signal]);
+	}
+	return processSignals;
+}
+
+function deregisterSigHooks(signals) {
+	for (const signal of Object.keys(signals)) {
+		process.removeListener(signal, signals[signal]);
+	}
+}