test: consolidate port-change tests into single deterministic test

Replace 3 timing-dependent real-timer tests with one fake-timer test
that covers port-change detection, debug logging, and backoff reset.

Author: EhabY

test/unit/remote/sshProcess.test.ts

@@ -36,6 +36,7 @@ describe("SshProcessMonitor", () => {
 	});
 
 	afterEach(() => {
+		vi.useRealTimers();
 		for (const m of activeMonitors) {
 			m.dispose();
 		}
@@ -205,106 +206,55 @@ describe("SshProcessMonitor", () => {
 		});
 
 		it("resets backoff when port changes in log file", async () => {
-			// Start with port 11111, no process on it
+			vi.useFakeTimers();
+
 			vol.fromJSON({
 				"/logs/ms-vscode-remote.remote-ssh/1-Remote - SSH.log":
 					"-> socksPort 11111 ->",
 			});
-
-			// No process found initially, then process found after port change
 			vi.mocked(find).mockResolvedValue([]);
 
+			const pollInterval = 100;
 			const logger = createMockLogger();
 			const monitor = createMonitor({
 				codeLogDir: "/logs/window1",
-				discoveryPollIntervalMs: 10,
-				maxDiscoveryBackoffMs: 5000,
+				discoveryPollIntervalMs: pollInterval,
+				maxDiscoveryBackoffMs: 10_000,
 				logger,
 			});
 
-			// Wait for several search attempts with backoff growing
-			await new Promise((r) => setTimeout(r, 80));
-
-			// Now change the port in the log — simulates VS Code reconnection
-			vol.fromJSON({
-				"/logs/ms-vscode-remote.remote-ssh/1-Remote - SSH.log":
-					"-> socksPort 22222 ->",
-			});
-
-			// After port change, make find return a process
-			vi.mocked(find).mockResolvedValue([
-				{ pid: 555, ppid: 1, name: "ssh", cmd: "ssh" },
-			]);
-
-			// The process should be found quickly since backoff resets on port change
-			const pid = await waitForEvent(monitor.onPidChange, 2000);
-			expect(pid).toBe(555);
+			const pids: Array<number | undefined> = [];
+			monitor.onPidChange((pid) => pids.push(pid));
 
-			// Verify port change was logged
+			// Backoff doubles each iteration: 100, 200, 400, 800, 1600, ...
+			// Total after 5 iterations = pollInterval * (2^5 - 1) = 3100ms
+			const fiveIterationsMs = pollInterval * (2 ** 5 - 1);
+			await vi.advanceTimersByTimeAsync(fiveIterationsMs - 1);
 			expect(logger.debug).toHaveBeenCalledWith(
-				"SSH port changed in log file: 11111 -> 22222",
+				"No process found listening on port 11111",
 			);
-		});
 
-		it("logs when port found but no process listening", async () => {
+			// Change port, simulates VS Code reconnection after sleep/wake
 			vol.fromJSON({
 				"/logs/ms-vscode-remote.remote-ssh/1-Remote - SSH.log":
-					"-> socksPort 12345 ->",
-			});
-
-			vi.mocked(find).mockResolvedValue([]);
-
-			const logger = createMockLogger();
-			const monitor = createMonitor({
-				codeLogDir: "/logs/window1",
-				logger,
+					"-> socksPort 22222 ->",
 			});
 
-			// Wait for at least one search attempt
-			await new Promise((r) => setTimeout(r, 30));
-			monitor.dispose();
-
+			// Trigger next iteration: detects port change, resets backoff, no pid
+			await vi.advanceTimersByTimeAsync(1);
 			expect(logger.debug).toHaveBeenCalledWith(
-				"No process found listening on port 12345",
+				"SSH port changed in log file: 11111 -> 22222",
 			);
-		});
-
-		it("detects port change across search attempts", async () => {
-			vol.fromJSON({
-				"/logs/ms-vscode-remote.remote-ssh/1-Remote - SSH.log":
-					"-> socksPort 11111 ->",
-			});
-
-			// First attempt: port 11111 with no process
-			// After port changes: port 22222 with process
-			let callCount = 0;
-			vi.mocked(find).mockImplementation(() => {
-				callCount++;
-				if (callCount >= 3) {
-					return Promise.resolve([
-						{ pid: 777, ppid: 1, name: "ssh", cmd: "ssh" },
-					]);
-				}
-				return Promise.resolve([]);
-			});
 
-			const logger = createMockLogger();
-			const monitor = createMonitor({
-				codeLogDir: "/logs/window1",
-				logger,
-			});
-
-			// Wait for first attempts with port 11111
-			await new Promise((r) => setTimeout(r, 30));
-
-			// Change port
-			vol.fromJSON({
-				"/logs/ms-vscode-remote.remote-ssh/1-Remote - SSH.log":
-					"-> socksPort 22222 ->",
-			});
+			// Process becomes available
+			vi.mocked(find).mockResolvedValue([
+				{ pid: 555, ppid: 1, name: "ssh", cmd: "ssh" },
+			]);
 
-			const pid = await waitForEvent(monitor.onPidChange, 2000);
-			expect(pid).toBe(777);
+			// With reset backoff, process found within 2 poll intervals.
+			// Without reset, backoff would be pollInterval * 2^5 = 3200ms.
+			await vi.advanceTimersByTimeAsync(pollInterval * 2);
+			expect(pids).toContain(555);
 		});
 
 		it("does not fire event when same process is found after stale check", async () => {