response.text_or_raise() workaround

Closes #632

docs/plugins/advanced-model-plugins.md

@@ -162,5 +162,8 @@ for prev_response in conversation.responses:
         messages.append(
             {"role": "user", "content": prev_response.prompt.prompt}
         )
-    messages.append({"role": "assistant", "content": prev_response.text()})
+    messages.append({"role": "assistant", "content": prev_response.text_or_raise()})
 ```
+The `response.text_or_raise()` method used there will return the text from the response or raise a `ValueError` exception if the response is an `AsyncResponse` instance that has not yet been fully resolved.
+
+This is a slightly weird hack to work around the common need to share logic for building up the `messages` list across both sync and async models.

llm/default_plugins/openai_models.py

@@ -375,7 +375,9 @@ def build_messages(self, prompt, conversation):
                     messages.append(
                         {"role": "user", "content": prev_response.prompt.prompt}
                     )
-                messages.append({"role": "assistant", "content": prev_response.text()})
+                messages.append(
+                    {"role": "assistant", "content": prev_response.text_or_raise()}
+                )
         if prompt.system and prompt.system != current_system:
             messages.append({"role": "system", "content": prompt.system})
         if not prompt.attachments:

llm/models.py

@@ -399,6 +399,11 @@ async def _force(self):
                 pass
         return self
 
+    def text_or_raise(self) -> str:
+        if not self._done:
+            raise ValueError("Response not yet awaited")
+        return "".join(self._chunks)
+
     async def text(self) -> str:
         await self._force()
         return "".join(self._chunks)