When raising error, show the current state vs expected state (#87)

Author: Mariatta

cherry_picker/cherry_picker.py

@@ -541,7 +541,9 @@ def abort_cherry_pick(self):
         run `git cherry-pick --abort` and then clean up the branch
         """
         if self.initial_state != WORKFLOW_STATES.BACKPORT_PAUSED:
-            raise ValueError("One can only abort a paused process.")
+            raise ValueError(
+                f"One can only abort a paused process. Current state: {self.initial_state}. Expected state: {WORKFLOW_STATES.BACKPORT_PAUSED}"
+            )
 
         try:
             validate_sha("CHERRY_PICK_HEAD")

cherry_picker/test_cherry_picker.py

@@ -1,5 +1,6 @@
 import os
 import pathlib
+import re
 import subprocess
 import warnings
 from collections import ChainMap
@@ -1141,7 +1142,7 @@ def test_continue_cherry_pick_invalid_state(tmp_git_repo_dir):
 
     assert get_state() == WORKFLOW_STATES.UNSET
 
-    with pytest.raises(ValueError, match=r"^One can only continue a paused process.$"):
+    with pytest.raises(ValueError, match=re.compile(r"^One can only continue a paused process.")):
         cherry_picker.continue_cherry_pick()
 
     assert get_state() == WORKFLOW_STATES.UNSET  # success
@@ -1167,7 +1168,7 @@ def test_abort_cherry_pick_invalid_state(tmp_git_repo_dir):
 
     assert get_state() == WORKFLOW_STATES.UNSET
 
-    with pytest.raises(ValueError, match=r"^One can only abort a paused process.$"):
+    with pytest.raises(ValueError, match=re.compile(r"^One can only abort a paused process.")):
         cherry_picker.abort_cherry_pick()