ENH: Emit correct logs when no diagnostics with octue get-diagnostics

octue/cli.py

@@ -307,13 +307,17 @@ def get_diagnostics(cloud_path, local_path, download_datasets):
             )
         )
 
-    GoogleCloudStorageClient().download_all_files(
+    local_paths = GoogleCloudStorageClient().download_all_files(
         local_path=local_path,
         cloud_path=cloud_path,
         filter=filter,
         recursive=True,
     )
 
+    if not local_paths:
+        logger.warning("No diagnostics found at %r.", cloud_path)
+        return
+
     # Update the manifests with the local paths of the datasets.
     if download_datasets:
         for manifest_type in ("configuration_manifest", "input_manifest"):

octue/cloud/storage/client.py

@@ -180,38 +180,42 @@ def download_all_files(self, local_path, cloud_path, filter=None, recursive=Fals
         :param str cloud_path: the path to a cloud storage directory to download
         :param callable|None filter: an optional callable to filter which files are downloaded from the cloud path; the callable should take a blob as its only positional argument
         :param bool recursive: if `True`, also download all files in all subdirectories of the cloud directory recursively
-        :return None:
+        :return list(str): the list of paths the files were downloaded to
         """
         bucket, _ = self._get_bucket_and_path_in_bucket(cloud_path)
 
-        cloud_and_local_paths = [
-            {
-                "cloud_path": storage.path.generate_gs_path(bucket.name, blob.name),
-                "local_path": os.path.join(
+        cloud_paths = []
+        local_paths = []
+
+        for blob in self.scandir(cloud_path, filter=filter, recursive=recursive):
+            cloud_paths.append(storage.path.generate_gs_path(bucket.name, blob.name))
+
+            local_paths.append(
+                os.path.join(
                     local_path,
                     storage.path.relpath(
                         storage.path.generate_gs_path(bucket.name, blob.name),
                         cloud_path,
                     ),
-                ),
-            }
-            for blob in self.scandir(cloud_path, filter=filter, recursive=recursive)
-        ]
+                )
+            )
 
-        if not cloud_and_local_paths:
+        if not cloud_paths:
             logger.warning(
                 "Attempted to download files from %r but it appears empty. Please check this is the correct path.",
                 cloud_path,
             )
-            return
+            return []
 
         def download_file(cloud_and_local_path):
-            self.download_to_file(cloud_and_local_path["local_path"], cloud_and_local_path["cloud_path"])
+            self.download_to_file(cloud_and_local_path[0], cloud_and_local_path[1])
 
         with concurrent.futures.ThreadPoolExecutor() as executor:
-            for path in executor.map(download_file, cloud_and_local_paths):
+            for path in executor.map(download_file, zip(local_paths, cloud_paths)):
                 logger.debug("Downloaded file to %r.", path)
 
+        return local_paths
+
     def download_as_string(self, cloud_path, timeout=_DEFAULT_TIMEOUT):
         """Download a file to a string from a Google Cloud bucket at gs://<bucket_name>/<path_in_bucket>.
 

tests/test_cli.py

@@ -268,6 +268,33 @@ def setUpClass(cls):
 
         diagnostics.upload(storage.path.join(cls.DIAGNOSTICS_CLOUD_PATH, cls.ANALYSIS_ID))
 
+    def test_warning_logged_if_no_diagnostics_found(self):
+        """Test that a warning about there being no diagnostics is logged if the diagnostics cloud path is empty."""
+        with tempfile.TemporaryDirectory() as temporary_directory:
+            result = CliRunner().invoke(
+                octue_cli,
+                [
+                    "get-diagnostics",
+                    storage.path.join(self.DIAGNOSTICS_CLOUD_PATH, "9f4ccee3-15b0-4a03-b5ac-c19e1d66a709"),
+                    "--local-path",
+                    temporary_directory,
+                ],
+            )
+
+        self.assertIn(
+            "Attempted to download files from 'gs://octue-sdk-python-test-bucket/diagnostics/9f4ccee3-15b0-4a03-b5ac-"
+            "c19e1d66a709' but it appears empty. Please check this is the correct path.",
+            result.output,
+        )
+
+        self.assertIn(
+            "No diagnostics found at 'gs://octue-sdk-python-test-bucket/diagnostics/9f4ccee3-15b0-4a03-b5ac-"
+            "c19e1d66a709'",
+            result.output,
+        )
+
+        self.assertNotIn("Downloaded diagnostics from", result.output)
+
     def test_get_diagnostics(self):
         """Test that only the values files, manifests, and questions file are downloaded when using the
         `get-diagnostics` CLI command.