validate prediction response to raise errors, but return the unvalida…

…ted output to avoid converting urls to File/Path

Signed-off-by: technillogue <technillogue@gmail.com>

python/cog/server/clients.py

@@ -188,7 +188,7 @@ async def chunk_file_reader() -> AsyncIterator[bytes]:
             if resp1.status_code == 307 and resp1.headers["Location"]:
                 log.info("got file upload redirect from api")
                 url = resp1.headers["Location"]
-        log.info("doing real upload to", url)
+        log.info("doing real upload to %s", url)
         resp = await self.file_client.put(
             url,
             content=chunk_file_reader(),

python/cog/server/http.py

@@ -316,8 +316,13 @@ async def shared_predict(
         if respond_async:
             return JSONResponse(jsonable_encoder(initial_response), status_code=202)
 
+        # by now, output Path and File are already converted to str
+        # so when we validate the schema, those urls get cast back to Path and File
+        # in the previous implementation those would then get encoded as strings
+        # however the changes to Path and File break this and return the filename instead
         try:
             prediction = await async_result
+            # we're only doing this to catch validation errors
             response = PredictionResponse(**prediction.dict())
         except ValidationError as e:
             _log_invalid_output(e)
@@ -329,7 +334,9 @@ async def shared_predict(
         # )
         # dict_resp["output"] = output
         # encoded_response = jsonable_encoder(dict_resp)
-        encoded_response = jsonable_encoder(response.dict())
+
+        # return *prediction* and not *response* to preserve urls
+        encoded_response = jsonable_encoder(prediction.dict())
         return JSONResponse(content=encoded_response)
 
     @app.post("/predictions/{prediction_id}/cancel")

python/tests/server/test_http_input.py

@@ -71,6 +71,8 @@ def test_default_int_input(client, match):
     assert resp.json() == match({"output": 9, "status": "succeeded"})
 
 
+# the data uri BytesIO gets consumed by jsonable_encoder
+# doesn't really matter that much for our purposes
 @uses_predictor("input_file")
 def test_file_input_data_url(client, match):
     resp = client.post(