test: implement tests using vitest framework

test/java.test.js

@@ -0,0 +1,112 @@
+import net from "node:net";
+import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
+import { pingJava } from "../lib/java.js";
+import varint from "../lib/varint.js";
+
+vi.mock("node:net");
+
+describe("pingJava", () => {
+	let mockSocket;
+
+	beforeEach(() => {
+		const mockHandlers = {};
+		mockSocket = {
+			write: vi.fn(),
+			destroy: vi.fn(),
+			setNoDelay: vi.fn(),
+			on: vi.fn((event, handler) => (mockHandlers[event] = handler)),
+			emit: vi.fn((event, ...args) => mockHandlers[event]?.(...args)),
+		};
+		net.createConnection = vi.fn().mockReturnValue(mockSocket);
+		vi.useFakeTimers();
+	});
+
+	afterEach(() => {
+		vi.restoreAllMocks();
+	});
+
+	it("should ping a server and handle a chunked response", async () => {
+		const host = "mc.hypixel.net";
+		const options = {
+			port: 25565,
+			timeout: 5000,
+			protocolVersion: 765,
+			virtualHost: "mc.hypixel.net",
+		};
+
+		const pingPromise = pingJava(host, options);
+
+		mockSocket.emit("connect");
+
+		expect(net.createConnection).toHaveBeenCalledWith({
+			host,
+			port: options.port,
+		});
+		expect(mockSocket.setNoDelay).toHaveBeenCalledWith(true);
+		expect(mockSocket.write).toHaveBeenCalledTimes(2);
+
+		const mockResponse = {
+			version: { name: "1.21", protocol: 765 },
+			players: { max: 20, online: 5, sample: [] },
+			description: "A Minecraft Server",
+			favicon: "data:image/png;base64,iVBORw0KGgo...",
+		};
+		const fullPacket = createMockJavaResponse(mockResponse);
+		const chunk1 = fullPacket.subarray(0, 10);
+		const chunk2 = fullPacket.subarray(10);
+
+		mockSocket.emit("data", chunk1);
+		mockSocket.emit("data", chunk2);
+
+		const result = await pingPromise;
+		expect(result).toEqual(mockResponse);
+		expect(mockSocket.destroy).toHaveBeenCalled();
+	});
+
+	describe("errors", () => {
+		it("should throw an error if host is not provided", () => {
+			expect(() => pingJava(null)).toThrow("Host argument is not provided");
+		});
+
+		it("should reject on socket timeout before data is received", async () => {
+			const pingPromise = pingJava("localhost", { timeout: 1000 });
+			mockSocket.emit("connect");
+
+			// Advance time to trigger the timeout
+			vi.advanceTimersByTime(1000);
+
+			await expect(pingPromise).rejects.toThrow("Socket timeout");
+			expect(mockSocket.destroy).toHaveBeenCalled();
+		});
+
+		it("should reject on connection error", async () => {
+			const pingPromise = pingJava("localhost");
+
+			// Simulate a connection refusal
+			mockSocket.emit("error", new Error("ECONNREFUSED"));
+
+			await expect(pingPromise).rejects.toThrow("ECONNREFUSED");
+		});
+
+		it("should only reject once, even if multiple errors occur", async () => {
+			const pingPromise = pingJava("localhost");
+
+			// Fire two errors back-to-back
+			mockSocket.emit("error", new Error("First error"));
+			mockSocket.emit("error", new Error("Second error"));
+
+			await expect(pingPromise).rejects.toThrow("First error");
+			expect(mockSocket.destroy).toHaveBeenCalledTimes(1);
+		});
+	});
+});
+
+function createMockJavaResponse(response) {
+	const jsonString = JSON.stringify(response);
+	const jsonBuffer = Buffer.from(jsonString, "utf8");
+	const responseLength = varint.encodeInt(jsonBuffer.length);
+	const packetId = varint.encodeInt(0);
+	const packetData = Buffer.concat([packetId, responseLength, jsonBuffer]);
+	const packetLength = varint.encodeInt(packetData.length);
+	return Buffer.concat([packetLength, packetData]);
+}