fixed command line overwrite options

Author: shimwell

openmc_data_downloader/openmc_data_downloader

@@ -66,11 +66,18 @@ if __name__ == '__main__':
     )
 
     parser.add_argument(
-        '-o', '--overwrite',
-        type=bool, default=True,
-        help='Should exiting files be overwritten'
+        '--overwrite',
+        action='store_true',
+        help='Exiting files will be overwritten'
     )
 
+    parser.add_argument(
+        '--no-overwrite',
+        action='store_false',
+        help='Exiting files will not be overwritten'
+    )
+
+    parser.set_defaults(overwrite=False)
     args = parser.parse_args()
 
     just_in_time_library_generator(

tests/test_command_line_usage.py

@@ -4,6 +4,7 @@
 
 
 import os
+import time
 import unittest
 from pathlib import Path
 
@@ -146,3 +147,22 @@ def test_sab_download_with_endf(self):
         assert Path("ENDFB-7.1-NNDC_c_Be_in_BeO.h5").is_file()
         assert Path("materials.xml").is_file()
         assert len(list(Path(".").glob("*.h5"))) == 5
+
+    def test_download_single_file_with_overwrite_speed_up(self):
+        """Checks that downloading with overwrite to False is quicker"""
+
+        current_time = time.time()
+        os.system(
+            "openmc_data_downloader -l ENDFB-7.1-NNDC TENDL-2019 -e Be --overwrite"
+        )
+        time_after_download = time.time()
+        time_to_download = time_after_download - current_time
+
+        current_time = time.time()
+        os.system(
+            "openmc_data_downloader -l ENDFB-7.1-NNDC TENDL-2019 -e Be --no-overwrite",
+        )
+        time_after_download = time.time()
+        time_to_not_download = time_after_download - current_time
+
+        assert time_to_not_download < time_to_download