Fix argument mismatch in split_cl.py

When adding tests, the LoadDescription function accidentally got called
with the wrong arguments in the main function. This fixes that; a future
CL (uploading shortly) adds more robust tests that would have caught this.

Bug: 389568463, 389069356
Change-Id: Icaf5e83cd8caa9f3975173f8c8ee7d92ef44ee56
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/6170638
Commit-Queue: Andy Perelson <ajp@google.com>
Reviewed-by: Brian Ryner <bryner@google.com>
Reviewed-by: Andy Perelson <ajp@google.com>
Auto-Submit: Devon Loehr <dloehr@google.com>

split_cl.py

@@ -218,8 +218,12 @@ def PrintClInfo(cl_index, num_cls, directories, file_paths, description,
     print()
 
 
-def LoadDescription(description_file):
+def LoadDescription(description_file, dry_run):
     if not description_file:
+        if not dry_run:
+            # Parser checks this as well, so should be impossible
+            raise ValueError(
+                "Must provide a description file except during dry runs")
         return ('Dummy description for dry run.\n'
                 'directory = $directory')
 

tests/split_cl_test.py

@@ -196,11 +196,21 @@ class SplitClTest(unittest.TestCase):
     @mock.patch("gclient_utils.FileRead", return_value="Description")
     def testLoadDescription(self, mock_file_read):
         # No description provided, use the dummy:
-        self.assertTrue(split_cl.LoadDescription(None).startswith("Dummy"))
+        self.assertTrue(
+            split_cl.LoadDescription(None, True).startswith("Dummy"))
         self.assertEqual(mock_file_read.call_count, 0)
 
-        # Description file provided, load it
-        self.assertEqual(split_cl.LoadDescription("SomeFile.txt"),
+        # No description provided during a real run
+        self.assertRaises(ValueError, split_cl.LoadDescription, None, False)
+        self.assertEqual(mock_file_read.call_count, 0)
+
+        # Description file provided, load it regardless of dry run
+        self.assertEqual(split_cl.LoadDescription("SomeFile.txt", False),
+                         "Description")
+        self.assertEqual(mock_file_read.call_count, 1)
+
+        mock_file_read.reset_mock()
+        self.assertEqual(split_cl.LoadDescription("SomeFile.txt", True),
                          "Description")
         self.assertEqual(mock_file_read.call_count, 1)