refactor: tighten backend, flows, frontend, tests; push flows to Langflow

backend/tests/_harness.py

@@ -0,0 +1,68 @@
+"""Shared e2e harness: free ports, health waits, lfx spawn, migrate, sessions.
+
+Single place for logic duplicated between tests/conftest.py and
+scripts/smoke_e2e.py (~60 lines). Full real-LFX runs are kept.
+"""
+
+from __future__ import annotations
+
+import os
+import shutil
+import socket
+import subprocess
+import sys
+import time
+import urllib.request
+from pathlib import Path
+
+
+def free_port() -> int:
+    sock = socket.socket()
+    sock.bind(("127.0.0.1", 0))
+    port = sock.getsockname()[1]
+    sock.close()
+    return port
+
+
+def wait_healthy(url: str, deadline_s: float = 240.0) -> None:
+    deadline = time.time() + deadline_s
+    while time.time() < deadline:
+        try:
+            with urllib.request.urlopen(url + "/health", timeout=3) as response:
+                if response.status == 200:
+                    return
+        except OSError:
+            time.sleep(1)
+    raise RuntimeError(f"server did not become healthy: {url}")
+
+
+def spawn_lfx(flow_dir: Path, port: int) -> subprocess.Popen:
+    bindir = Path(sys.executable).parent
+    lfx_bin = shutil.which("lfx", path=str(bindir)) or "lfx"
+    env = {**os.environ, "LANGFLOW_API_KEY": "", "LFX_API_KEY": "test-lfx-key"}
+    return subprocess.Popen(
+        [
+            lfx_bin,
+            "serve",
+            "--host",
+            "127.0.0.1",
+            "--port",
+            str(port),
+            "--flow-dir",
+            str(flow_dir),
+            str(flow_dir),
+        ],
+        stdout=subprocess.PIPE,
+        stderr=subprocess.STDOUT,
+        text=True,
+        env=env,
+    )
+
+
+def migrate_throwaway(backend_dir: Path) -> None:
+    from alembic import command as alembic_command
+    from alembic.config import Config
+
+    cfg = Config()
+    cfg.set_main_option("script_location", str(backend_dir / "migrations"))
+    alembic_command.upgrade(cfg, "head")