Handle missing npx.cmd fallback on Windows 🤖 Generated with GPT-5.2-Codex (#3416)

src/fastmcp/cli/cli.py

@@ -54,7 +54,7 @@ def _get_npx_command():
             try:
                 subprocess.run([cmd, "--version"], check=True, capture_output=True)
                 return cmd
-            except subprocess.CalledProcessError:
+            except (subprocess.CalledProcessError, FileNotFoundError):
                 continue
         return None
     return "npx"  # On Unix-like systems, just use npx

tests/cli/test_cli.py

@@ -440,6 +440,23 @@ class TestWindowsSpecific:
             assert result == "npx.exe"
             assert mock_run.call_count == 2
 
+    @patch("subprocess.run")
+    def test_get_npx_command_windows_cmd_missing(self, mock_run):
+        """Test npx command detection continues when npx.cmd is missing."""
+        from fastmcp.cli.cli import _get_npx_command
+
+        with patch("sys.platform", "win32"):
+            # Missing npx.cmd should not abort detection
+            mock_run.side_effect = [
+                FileNotFoundError("npx.cmd not found"),
+                Mock(returncode=0),
+            ]
+
+            result = _get_npx_command()
+
+            assert result == "npx.exe"
+            assert mock_run.call_count == 2
+
     @patch("subprocess.run")
     def test_get_npx_command_windows_fallback(self, mock_run):
         """Test npx command detection on Windows with plain npx."""