test: add infra coverage and fix web logging

src/infra/ports.test.ts

@@ -0,0 +1,32 @@
+import net from "node:net";
+import { describe, expect, it, vi } from "vitest";
+
+import { ensurePortAvailable, handlePortError, PortInUseError } from "./ports.js";
+
+describe("ports helpers", () => {
+	it("ensurePortAvailable rejects when port busy", async () => {
+		const server = net.createServer();
+		await new Promise((resolve) => server.listen(0, resolve));
+		const port = (server.address() as net.AddressInfo).port;
+		await expect(ensurePortAvailable(port)).rejects.toBeInstanceOf(
+			PortInUseError,
+		);
+		server.close();
+	});
+
+	it("handlePortError exits nicely on EADDRINUSE", async () => {
+		const runtime = {
+			error: vi.fn(),
+			log: vi.fn(),
+			exit: vi.fn() as unknown as (code: number) => never,
+		};
+		await handlePortError(
+			{ code: "EADDRINUSE" },
+			1234,
+			"context",
+			runtime,
+		).catch(() => {});
+		expect(runtime.error).toHaveBeenCalled();
+		expect(runtime.exit).toHaveBeenCalledWith(1);
+	});
+});