chore: isolate build artifacts and storybook smoke infra

tests/e2e/support/storybook-server.cjs

@@ -0,0 +1,171 @@
+const { spawn } = require("node:child_process");
+const fs = require("node:fs/promises");
+const path = require("node:path");
+
+const repoRoot = path.resolve(__dirname, "../../..");
+const docsDir = path.resolve(repoRoot, "apps/docs");
+const stateFile = path.resolve(repoRoot, ".artifacts/test-results/storybook-server.json");
+
+const baseURL = "http://127.0.0.1:6006";
+const startupTimeoutMs = 120_000;
+const shutdownTimeoutMs = 10_000;
+const pollIntervalMs = 250;
+const storybookCommand = process.platform === "win32" ? "pnpm.cmd" : "pnpm";
+const storybookArgs = ["run", "storybook"];
+const reuseExistingServer = !process.env.CI;
+
+function sleep(ms) {
+  return new Promise((resolve) => setTimeout(resolve, ms));
+}
+
+async function isServerResponsive() {
+  try {
+    const response = await fetch(baseURL, {
+      redirect: "manual",
+      signal: AbortSignal.timeout(1_000)
+    });
+
+    return response.status < 404 || [400, 401, 402, 403].includes(response.status);
+  } catch {
+    return false;
+  }
+}
+
+async function waitFor(condition, timeoutMs, failureMessage) {
+  const deadline = Date.now() + timeoutMs;
+
+  while (Date.now() < deadline) {
+    if (await condition()) {
+      return;
+    }
+
+    await sleep(pollIntervalMs);
+  }
+
+  throw new Error(failureMessage);
+}
+
+async function ensureStateDir() {
+  await fs.mkdir(path.dirname(stateFile), { recursive: true });
+}
+
+async function readServerState() {
+  try {
+    const raw = await fs.readFile(stateFile, "utf8");
+    return JSON.parse(raw);
+  } catch {
+    return null;
+  }
+}
+
+async function clearServerState() {
+  await fs.rm(stateFile, { force: true });
+}
+
+async function stopProcess(pid) {
+  try {
+    if (process.platform === "win32") {
+      process.kill(pid, "SIGTERM");
+    } else {
+      process.kill(-pid, "SIGTERM");
+    }
+  } catch (error) {
+    if (error && error.code === "ESRCH") {
+      return;
+    }
+
+    throw error;
+  }
+
+  try {
+    await waitFor(
+      async () => !(await isServerResponsive()),
+      shutdownTimeoutMs,
+      `Timed out waiting ${shutdownTimeoutMs}ms for Storybook to stop.`
+    );
+  } catch {
+    try {
+      if (process.platform === "win32") {
+        process.kill(pid, "SIGKILL");
+      } else {
+        process.kill(-pid, "SIGKILL");
+      }
+    } catch (error) {
+      if (!error || error.code !== "ESRCH") {
+        throw error;
+      }
+    }
+  }
+}
+
+async function startStorybookServer() {
+  if (await isServerResponsive()) {
+    if (reuseExistingServer) {
+      return;
+    }
+
+    throw new Error(`${baseURL} is already in use, and CI runs must start their own Storybook server.`);
+  }
+
+  const child = spawn(storybookCommand, storybookArgs, {
+    cwd: docsDir,
+    detached: process.platform !== "win32",
+    env: process.env,
+    shell: false,
+    stdio: "ignore"
+  });
+
+  const exitPromise = new Promise((_, reject) => {
+    child.once("error", (error) => {
+      reject(error);
+    });
+
+    child.once("exit", (code, signal) => {
+      reject(
+        new Error(
+          `Storybook exited before becoming ready (code: ${code ?? "null"}, signal: ${signal ?? "null"}).`
+        )
+      );
+    });
+  });
+
+  try {
+    await Promise.race([
+      waitFor(
+        async () => isServerResponsive(),
+        startupTimeoutMs,
+        `Timed out waiting ${startupTimeoutMs}ms for Storybook on ${baseURL}.`
+      ),
+      exitPromise
+    ]);
+  } catch (error) {
+    await stopProcess(child.pid);
+    throw error;
+  }
+
+  child.unref();
+
+  await ensureStateDir();
+  await fs.writeFile(stateFile, JSON.stringify({ pid: child.pid }, null, 2));
+}
+
+async function stopStorybookServer() {
+  const state = await readServerState();
+
+  if (!state) {
+    return;
+  }
+
+  try {
+    await stopProcess(state.pid);
+  } finally {
+    await clearServerState();
+  }
+}
+
+module.exports = {
+  clearServerState,
+  readServerState,
+  startStorybookServer,
+  stopStorybookServer
+};