refactor demos (#398)

demos/shared/test_runner/common.py

@@ -0,0 +1,35 @@
+import json
+
+
+ARCH_STATE_HEADER = "x-arch-state"
+
+
+def get_data_chunks(stream, n=1):
+    chunks = []
+    for chunk in stream.iter_lines():
+        if chunk:
+            chunk = chunk.decode("utf-8")
+            chunk_data_id = chunk[0:6]
+            assert chunk_data_id == "data: "
+            chunk_data = chunk[6:]
+            chunk_data = chunk_data.strip()
+            chunks.append(chunk_data)
+            if len(chunks) >= n:
+                break
+    return chunks
+
+
+def get_arch_messages(response_json):
+    arch_messages = []
+    if response_json and "metadata" in response_json:
+        # load arch_state from metadata
+        arch_state_str = response_json.get("metadata", {}).get(ARCH_STATE_HEADER, "{}")
+        # parse arch_state into json object
+        arch_state = json.loads(arch_state_str)
+        # load messages from arch_state
+        arch_messages_str = arch_state.get("messages", "[]")
+        # parse messages into json object
+        arch_messages = json.loads(arch_messages_str)
+        # append messages from arch gateway to history
+        return arch_messages
+    return []