test(e2e): isolate prompt tests with per-worker backend (#20464)

1 files changed, 119 insertions, 0 deletions

diff --git a/packages/app/e2e/backend.ts b/packages/app/e2e/backend.ts
new file mode 100644
index 000000000..2acbe7179
--- /dev/null
+++ b/packages/app/e2e/backend.ts
@@ -0,0 +1,119 @@
+import { spawn } from "node:child_process"
+import fs from "node:fs/promises"
+import net from "node:net"
+import os from "node:os"
+import path from "node:path"
+import { fileURLToPath } from "node:url"
+
+type Handle = {
+  url: string
+  stop: () => Promise<void>
+}
+
+function freePort() {
+  return new Promise<number>((resolve, reject) => {
+    const server = net.createServer()
+    server.once("error", reject)
+    server.listen(0, () => {
+      const address = server.address()
+      if (!address || typeof address === "string") {
+        server.close(() => reject(new Error("Failed to acquire a free port")))
+        return
+      }
+      server.close((err) => {
+        if (err) reject(err)
+        else resolve(address.port)
+      })
+    })
+  })
+}
+
+async function waitForHealth(url: string, probe = "/global/health") {
+  const end = Date.now() + 120_000
+  let last = ""
+  while (Date.now() < end) {
+    try {
+      const res = await fetch(`${url}${probe}`)
+      if (res.ok) return
+      last = `status ${res.status}`
+    } catch (err) {
+      last = err instanceof Error ? err.message : String(err)
+    }
+    await new Promise((resolve) => setTimeout(resolve, 250))
+  }
+  throw new Error(`Timed out waiting for backend health at ${url}${probe}${last ? ` (${last})` : ""}`)
+}
+
+const LOG_CAP = 100
+
+function cap(input: string[]) {
+  if (input.length > LOG_CAP) input.splice(0, input.length - LOG_CAP)
+}
+
+function tail(input: string[]) {
+  return input.slice(-40).join("")
+}
+
+export async function startBackend(label: string): Promise<Handle> {
+  const port = await freePort()
+  const sandbox = await fs.mkdtemp(path.join(os.tmpdir(), `opencode-e2e-${label}-`))
+  const appDir = path.resolve(path.dirname(fileURLToPath(import.meta.url)), "..")
+  const repoDir = path.resolve(appDir, "../..")
+  const opencodeDir = path.join(repoDir, "packages", "opencode")
+  const env = {
+    ...process.env,
+    OPENCODE_DISABLE_SHARE: process.env.OPENCODE_DISABLE_SHARE ?? "true",
+    OPENCODE_DISABLE_LSP_DOWNLOAD: "true",
+    OPENCODE_DISABLE_DEFAULT_PLUGINS: "true",
+    OPENCODE_EXPERIMENTAL_DISABLE_FILEWATCHER: "true",
+    OPENCODE_TEST_HOME: path.join(sandbox, "home"),
+    XDG_DATA_HOME: path.join(sandbox, "share"),
+    XDG_CACHE_HOME: path.join(sandbox, "cache"),
+    XDG_CONFIG_HOME: path.join(sandbox, "config"),
+    XDG_STATE_HOME: path.join(sandbox, "state"),
+    OPENCODE_CLIENT: "app",
+    OPENCODE_STRICT_CONFIG_DEPS: "true",
+  } satisfies Record<string, string | undefined>
+  const out: string[] = []
+  const err: string[] = []
+  const proc = spawn(
+    "bun",
+    ["run", "--conditions=browser", "./src/index.ts", "serve", "--port", String(port), "--hostname", "127.0.0.1"],
+    {
+      cwd: opencodeDir,
+      env,
+      stdio: ["ignore", "pipe", "pipe"],
+    },
+  )
+  proc.stdout?.on("data", (chunk) => { out.push(String(chunk)); cap(out) })
+  proc.stderr?.on("data", (chunk) => { err.push(String(chunk)); cap(err) })
+
+  const url = `http://127.0.0.1:${port}`
+  try {
+    await waitForHealth(url)
+  } catch (error) {
+    proc.kill("SIGTERM")
+    await fs.rm(sandbox, { recursive: true, force: true }).catch(() => undefined)
+    throw new Error(
+      [
+        `Failed to start isolated e2e backend for ${label}`,
+        error instanceof Error ? error.message : String(error),
+        tail(out),
+        tail(err),
+      ]
+        .filter(Boolean)
+        .join("\n"),
+    )
+  }
+
+  return {
+    url,
+    async stop() {
+      if (proc.exitCode === null) {
+        proc.kill("SIGTERM")
+        await new Promise((resolve) => proc.once("exit", () => resolve(undefined))).catch(() => undefined)
+      }
+      await fs.rm(sandbox, { recursive: true, force: true }).catch(() => undefined)
+    },
+  }
+}