Checkpoint 3: deliver playable samples and complete native authoring workflows

tests/mcp_stdio_test.py

@@ -40,6 +40,7 @@ def run(executable, project):
         assert initialized["result"]["serverInfo"]["name"] == "faset-editor"
         process.stdin.write('{"jsonrpc":"2.0","method":"notifications/initialized"}\n')
         process.stdin.flush()
+        assert call("faset_schema_status")["stale"]
         names = {tool["name"] for tool in request("tools/list")["result"]["tools"]}
         assert {"faset_scene_edit", "faset_export", "faset_job_cancel", "faset_plugins"} <= names
         assert "faset_runtime_query" not in names and "faset_editor_capture" not in names
@@ -78,7 +79,38 @@ def run(executable, project):
         assert code == 0, errors
 
 
+def disconnected_output(executable, project):
+    process = subprocess.Popen([executable, "--project", str(project), "--mcp"],
+                               stdin=subprocess.PIPE, stdout=subprocess.PIPE,
+                               stderr=subprocess.PIPE, text=True, encoding="utf-8")
+    # Keep input open: output failure itself must close the transport. Before
+    # the fix this terminated the POSIX Editor with SIGPIPE (return code -13).
+    process.stdout.close()
+    try:
+        process.stdin.write(json.dumps({"jsonrpc": "2.0", "id": 1, "method": "initialize",
+            "params": {"protocolVersion": "2025-06-18"}}) + "\n")
+        process.stdin.flush()
+        assert process.wait(timeout=20) == 0, process.stderr.read()
+    finally:
+        if process.poll() is None:
+            process.kill()
+            process.wait()
+        process.stdin.close()
+
+
+def eof_tail(executable, project):
+    # A final buffered request must still receive its reply when input closes.
+    message = json.dumps({"jsonrpc": "2.0", "id": "tail", "method": "ping"})
+    result = subprocess.run([executable, "--project", str(project), "--mcp"],
+                            input=message, capture_output=True, text=True,
+                            encoding="utf-8", timeout=20)
+    assert result.returncode == 0, result.stderr
+    assert json.loads(result.stdout)["id"] == "tail", result.stdout
+
+
 with tempfile.TemporaryDirectory(prefix="faset-mcp-stdio-") as temporary:
     run(sys.argv[1], pathlib.Path(temporary))
     run(sys.argv[1], pathlib.Path(temporary))
-print("Real MCP stdio lifecycle, clean stdout, revision conflict, retry, Undo/Redo, disk reopen and process shutdown passed")
+    disconnected_output(sys.argv[1], pathlib.Path(temporary))
+    eof_tail(sys.argv[1], pathlib.Path(temporary))
+print("Real MCP stdio lifecycle, clean stdout, revision conflict, retry, Undo/Redo, disk reopen, broken output pipe and EOF shutdown passed")