test: Add profile utils test

Author: matz3

packages/cli/test/lib/utils/profile.js

@@ -0,0 +1,169 @@
+import test from "ava";
+import sinon from "sinon";
+import esmock from "esmock";
+
+function createSessionStubs() {
+	const connectStub = sinon.stub();
+	const postStub = sinon.stub().callsFake(async (method) => {
+		if (method === "Profiler.stop") {
+			return {profile: {foo: "bar"}};
+		}
+		return {};
+	});
+	class Session {
+		connect() {
+			return connectStub();
+		}
+		post(method) {
+			return postStub(method);
+		}
+	}
+	return {Session, connectStub, postStub};
+}
+
+test.afterEach.always(() => {
+	sinon.restore();
+});
+
+test.serial("start() enables and starts profiler and registers signals", async (t) => {
+	const {Session, connectStub, postStub} = createSessionStubs();
+	const writeFileSyncStub = sinon.stub();
+
+	const installed = new Map();
+	const onStub = sinon.stub(process, "on").callsFake((signal, handler) => {
+		installed.set(signal, handler);
+		return process;
+	});
+	const removeListenerStub = sinon.stub(process, "removeListener");
+
+	const {start, stop} = await esmock("../../../lib/utils/profile.js", {
+		"node:inspector/promises": {Session},
+		"node:fs": {writeFileSync: writeFileSyncStub}
+	});
+
+	await start();
+
+	t.true(connectStub.calledOnce, "session.connect called once");
+	t.true(postStub.calledWith("Profiler.enable"), "Profiler.enable posted");
+	t.true(postStub.calledWith("Profiler.start"), "Profiler.start posted");
+
+	// Four signals should be registered
+	t.true(onStub.calledWith("SIGHUP"));
+	t.true(onStub.calledWith("SIGINT"));
+	t.true(onStub.calledWith("SIGTERM"));
+	t.true(onStub.calledWith("SIGBREAK"));
+
+	// Cleanup to reset internal state
+	await stop();
+
+	// stop should deregister the same handlers
+	t.true(removeListenerStub.calledWith("SIGHUP", installed.get("SIGHUP")));
+	t.true(removeListenerStub.calledWith("SIGINT", installed.get("SIGINT")));
+	t.true(removeListenerStub.calledWith("SIGTERM", installed.get("SIGTERM")));
+	t.true(removeListenerStub.calledWith("SIGBREAK", installed.get("SIGBREAK")));
+});
+
+test.serial("start() is idempotent", async (t) => {
+	const {Session, connectStub} = createSessionStubs();
+	const writeFileSyncStub = sinon.stub();
+
+	sinon.stub(process, "on").returns(process);
+	sinon.stub(process, "removeListener");
+
+	const {start, stop} = await esmock("../../../lib/utils/profile.js", {
+		"node:inspector/promises": {Session},
+		"node:fs": {writeFileSync: writeFileSyncStub}
+	});
+
+	await start();
+	await start();
+	t.true(connectStub.calledOnce, "connect should be called only once");
+
+	await stop();
+});
+
+test.serial("stop() writes profile and deregisters signals", async (t) => {
+	const {Session, postStub} = createSessionStubs();
+	const writeFileSyncStub = sinon.stub();
+
+	const installed = new Map();
+	sinon.stub(process, "on").callsFake((signal, handler) => {
+		installed.set(signal, handler);
+		return process;
+	});
+	const removeListenerStub = sinon.stub(process, "removeListener");
+
+	const {start, stop} = await esmock("../../../lib/utils/profile.js", {
+		"node:inspector/promises": {Session},
+		"node:fs": {writeFileSync: writeFileSyncStub}
+	});
+
+	await start();
+	t.true(postStub.calledWith("Profiler.start"));
+
+	await stop();
+
+	t.true(writeFileSyncStub.calledOnce, "profile written once");
+	const [fileName, content] = writeFileSyncStub.firstCall.args;
+	t.regex(fileName, /^\.\/ui5_\d{4}-\d{2}-\d{2}_\d{2}-\d{2}-\d{2}\.cpuprofile$/, "filename matches pattern");
+	t.deepEqual(JSON.parse(content), {foo: "bar"}, "written profile content matches");
+
+	t.true(removeListenerStub.calledWith("SIGHUP", installed.get("SIGHUP")));
+	t.true(removeListenerStub.calledWith("SIGINT", installed.get("SIGINT")));
+	t.true(removeListenerStub.calledWith("SIGTERM", installed.get("SIGTERM")));
+	t.true(removeListenerStub.calledWith("SIGBREAK", installed.get("SIGBREAK")));
+});
+
+test.serial("stop() without start is a no-op", async (t) => {
+	const writeFileSyncStub = sinon.stub();
+
+	const removeListenerStub = sinon.stub(process, "removeListener");
+
+	const {stop} = await esmock("../../../lib/utils/profile.js", {
+		"node:inspector/promises": {Session: class {}},
+		"node:fs": {writeFileSync: writeFileSyncStub}
+	});
+
+	await stop();
+
+	t.true(removeListenerStub.notCalled, "no signal deregistration happened");
+	t.true(writeFileSyncStub.notCalled, "no write happened");
+});
+
+test.serial("signal handler stops profiling and exits", async (t) => {
+	const {Session, postStub} = createSessionStubs();
+	const writeFileSyncStub = sinon.stub();
+
+	const installed = new Map();
+	sinon.stub(process, "on").callsFake((signal, handler) => {
+		installed.set(signal, handler);
+		return process;
+	});
+	const removeListenerStub = sinon.stub(process, "removeListener");
+	const exitStub = sinon.stub(process, "exit");
+
+	const {start} = await esmock("../../../lib/utils/profile.js", {
+		"node:inspector/promises": {Session},
+		"node:fs": {writeFileSync: writeFileSyncStub}
+	});
+
+	await start();
+
+	t.true(typeof installed.get("SIGINT") === "function", "SIGINT handler registered");
+
+	// Trigger the signal handler
+	installed.get("SIGINT")();
+
+	// Allow the Promise chain in the handler (stop().then(...)) to run
+	await new Promise((resolve) => setImmediate(resolve));
+
+	t.true(postStub.calledWith("Profiler.stop"), "Profiler.stop posted via handler");
+	t.true(writeFileSyncStub.calledOnce, "profile written by handler");
+	t.true(exitStub.calledWith(128 + 2), "process.exit called with SIGINT code");
+
+	// Signals should be deregistered during stop
+	t.true(removeListenerStub.calledWith("SIGHUP", installed.get("SIGHUP")));
+	t.true(removeListenerStub.calledWith("SIGINT", installed.get("SIGINT")));
+	t.true(removeListenerStub.calledWith("SIGTERM", installed.get("SIGTERM")));
+	t.true(removeListenerStub.calledWith("SIGBREAK", installed.get("SIGBREAK")));
+});