update auxiliary download condition

geospaas_processing/converters/base.py

@@ -78,13 +78,15 @@ def make_symlink(source, destination):
             os.symlink(source, destination)
 
     @classmethod
-    def download_auxiliary_files(cls):
+    def download_auxiliary_files(cls, force_download=False):
         """Download the auxiliary files necessary for IDF conversion.
         They are too big to be included in the package.
         """
         url = cls.auxiliary_url.format(cls.auxiliary_version)
         auxiliary_archive_path = cls.auxiliary_path / 'auxiliary.tar.gz'
-        if not (cls.downloaded_aux or cls.auxiliary_path.is_dir()):
+        if (force_download or
+            not (cls.downloaded_aux or
+                 (cls.auxiliary_path.is_dir() and list(cls.auxiliary_path.iterdir())))):
             logger.info(
                 "Downloading auxiliary files for conversions, this may take a while. "
                 "Download path: %s", str(cls.auxiliary_path))

tests/converters/test_base.py

@@ -117,11 +117,12 @@ def test_convert(self):
 class AuxiliaryDownloadTestCase(unittest.TestCase):
     """Test the download of auxiliary files"""
 
-    def test_do_not_download_auxiliary_files_if_folder_present(self):
+    def test_do_not_download_auxiliary_files_if_folder_not_empty(self):
         """Test that auxiliary files are not downloaded if the folder
         is present
         """
         with mock.patch('pathlib.Path.is_dir', return_value=True), \
+             mock.patch('pathlib.Path.iterdir', return_value=iter(['baz'])), \
                 mock.patch('geospaas_processing.utils.http_request') as mock_http_request, \
                 mock.patch.object(TestConversionManager, 'make_symlink') as mock_make_symlink:
             TestConversionManager.download_auxiliary_files()