diff --git a/tests/test_api/test_file_storage_backends.py b/tests/test_api/test_file_storage_backends.py
index 89e3d5db..62910f10 100644
--- a/tests/test_api/test_file_storage_backends.py
+++ b/tests/test_api/test_file_storage_backends.py
@@ -1,9 +1,10 @@
 import typing
+from unittest import mock
 
 from pillar.tests import AbstractPillarTest
 
 
-class LocalStorageBackendTest(AbstractPillarTest):
+class AbstractStorageBackendTest(AbstractPillarTest):
     def create_test_file(self) -> (typing.IO, bytes):
         import io
         import secrets
@@ -13,6 +14,20 @@ class LocalStorageBackendTest(AbstractPillarTest):
 
         return test_file, file_contents
 
+    def assert_valid_file(self, expected_file_contents: bytes, url: str):
+        resp = self.get(url)
+
+        self.assertEqual(200, resp.status_code)
+        self.assertEqual(len(expected_file_contents), int(resp.headers['Content-Length']))
+        self.assertEqual(expected_file_contents, resp.data)
+
+
+class LocalStorageBackendTest(AbstractStorageBackendTest):
+    def storage_backend(self):
+        from pillar.api.file_storage_backends import Bucket
+
+        return Bucket.for_backend('local')
+
     def test_upload_download(self):
         test_file, file_contents = self.create_test_file()
 
@@ -24,19 +39,33 @@ class LocalStorageBackendTest(AbstractPillarTest):
             # We should be able to upload the file, and then download it again
             # from the URL given by its blob.
             blob.create_from_file(test_file, file_size=512, content_type='application/octet-stream')
-
             url = blob.get_url(is_public=True)
 
-        resp = self.get(url)
+        self.assert_valid_file(file_contents, url)
 
-        self.assertEqual(200, resp.status_code)
-        self.assertEqual('512', resp.headers['Content-Length'])
-        self.assertEqual(file_contents, resp.data)
+    def test_upload_from_path(self):
+        import tempfile
+        import pathlib
 
-    def storage_backend(self):
-        from pillar.api.file_storage_backends import Bucket
+        test_file, file_contents = self.create_test_file()
+        with tempfile.TemporaryDirectory() as tmpdir:
+            test_file_path = pathlib.Path(tmpdir) / 'testfile.bin'
 
-        return Bucket.for_backend('local')
+            with test_file_path.open('wb') as outfile:
+                outfile.write(file_contents)
+
+            with self.app.test_request_context():
+                bucket_class = self.storage_backend()
+                bucket = bucket_class('buckettest')
+                blob = bucket.blob('somefile.bin')
+
+                # We should be able to upload the file, and then download it again
+                # from the URL given by its blob, even after the original file was removed.
+                blob.upload_from_path(test_file_path, content_type='application/octet-stream')
+                url = blob.get_url(is_public=True)
+
+        self.assertFalse(test_file_path.exists())
+        self.assert_valid_file(file_contents, url)
 
     def test_copy_to_bucket(self):
         from bson import ObjectId
@@ -64,3 +93,45 @@ class LocalStorageBackendTest(AbstractPillarTest):
         self.assertEqual(200, resp.status_code)
         self.assertEqual('512', resp.headers['Content-Length'])
         self.assertEqual(file_contents, resp.data)
+
+
+class MockedGoogleCloudStorageTest(AbstractStorageBackendTest):
+    def storage_backend(self):
+        from pillar.api.file_storage_backends import Bucket
+
+        return Bucket.for_backend('gcs')
+
+    def test_file_upload(self):
+        import pillar.api.file_storage_backends.gcs as gcs
+        from gcloud.storage import Client, Bucket, Blob
+
+        # Set up mock GCS client
+        mock_gcs_client = gcs.gcs = mock.MagicMock(name='mock_gcs_client', autospec=Client)
+        mock_bucket = mock.MagicMock(name='mock_bucket', autospec=Bucket)
+        mock_blob = mock.MagicMock(name='mock_blob', autospec=Blob)
+
+        mock_gcs_client.get_bucket.return_value = mock_bucket
+        mock_bucket.blob.return_value = mock_blob
+        mock_blob.public_url = '/path/to/somefile.bin'
+        mock_blob.size = 318
+
+        test_file, file_contents = self.create_test_file()
+
+        with self.app.test_request_context():
+            bucket_class = self.storage_backend()
+            bucket = bucket_class('buckettest')
+            blob = bucket.blob('somefile.bin')
+
+            # We should be able to upload the file, and then download it again
+            # from the URL given by its blob.
+            blob.create_from_file(test_file, file_size=512, content_type='application/octet-stream')
+            url = blob.get_url(is_public=True)
+            self.assertIn('somefile.bin', url)
+
+            # Google-reported size should take precedence over reality.
+            self.assertEqual(318, blob.size)
+
+        mock_blob.upload_from_file.assert_called_with(test_file,
+                                                      size=512,
+                                                      content_type='application/octet-stream')
+        mock_blob.reload.assert_called_once()