test: use bun for mcp server mock (#95)

* test: launch mock server with shebang

* chore(flake): remove node_modules install

bun install all deps automatically

* test: remove bun install

* fix(test): use -S flag in shebang for Linux compatibility

The shebang `#!/usr/bin/env bun run` works on macOS but fails on Linux
because the `env` command doesn't split space-separated arguments by
default. Using `#!/usr/bin/env -S bun run` makes env parse the string
as multiple arguments, enabling cross-platform compatibility.

Fixes CI failures where the mock server couldn't start due to:
  /usr/bin/env: 'bun run': No such file or directory

Author: ryoppippi

flake.nix

@@ -120,15 +120,6 @@
                 uv sync --all-extras
               fi
 
-              # Install Node.js dependencies for MCP mock server (used in tests)
-              if [ -f vendor/stackone-ai-node/package.json ]; then
-                if [ ! -f vendor/stackone-ai-node/node_modules/.pnpm/lock.yaml ] || \
-                   [ vendor/stackone-ai-node/pnpm-lock.yaml -nt vendor/stackone-ai-node/node_modules/.pnpm/lock.yaml ]; then
-                  echo "📦 Installing MCP mock server dependencies..."
-                  (cd vendor/stackone-ai-node && pnpm install --frozen-lockfile)
-                fi
-              fi
-
               # Install git hooks
               ${config.pre-commit.installationScript}
             '';

tests/conftest.py

@@ -3,7 +3,6 @@
 from __future__ import annotations
 
 import os
-import shutil
 import socket
 import subprocess
 import time
@@ -61,30 +60,16 @@ def test_mcp_integration(mcp_mock_server):
     if not vendor_dir.exists():
         pytest.skip("stackone-ai-node submodule not found. Run 'git submodule update --init'")
 
-    # Check for bun runtime
-    bun_path = shutil.which("bun")
-    if not bun_path:
-        pytest.skip("bun not found. Install via Nix flake.")
-
+    # find port
     port = _find_free_port()
     base_url = f"http://localhost:{port}"
 
-    # Install dependencies if needed
-    node_modules = vendor_dir / "node_modules"
-    if not node_modules.exists():
-        subprocess.run(
-            [bun_path, "install"],
-            cwd=vendor_dir,
-            check=True,
-            capture_output=True,
-        )
-
     # Start the server from project root
     env = os.environ.copy()
     env["PORT"] = str(port)
 
     process = subprocess.Popen(
-        [bun_path, "run", str(serve_script)],
+        [str(serve_script)],
         cwd=project_root,
         env=env,
         stdout=subprocess.PIPE,

tests/mocks/serve.ts

@@ -1,8 +1,11 @@
+#!/usr/bin/env -S bun run
 /**
  * Standalone HTTP server for MCP mock testing.
  * Imports createMcpApp from stackone-ai-node vendor submodule.
  *
  * Usage:
+ *   ./tests/mocks/serve.ts [port]
+ *   # or
  *   bun run tests/mocks/serve.ts [port]
  */
 import { Hono } from "hono";