Add reversed option when listing history of revisions

Author: vinthara

alembic/command.py

@@ -561,6 +561,7 @@ def history(
     rev_range: Optional[str] = None,
     verbose: bool = False,
     indicate_current: bool = False,
+    reversed: bool = False,
 ) -> None:
     """List changeset scripts in chronological order.
 
@@ -592,7 +593,7 @@ def history(
 
     def _display_history(config, script, base, head, currents=()):
         for sc in script.walk_revisions(
-            base=base or "base", head=head or "heads"
+            base=base or "base", head=head or "heads", reversed=reversed
         ):
             if indicate_current:
                 sc._db_current_indicator = sc.revision in currents

alembic/config.py

@@ -756,6 +756,14 @@ def __init__(self, prog: Optional[str] = None) -> None:
                 "generating one",
             ),
         ),
+        "reversed": (
+            "-R",
+            "--reversed",
+            dict(
+                action="store_true",
+                help="Show the history in the reversed order",
+            ),
+        ),
         "version_path": (
             "--version-path",
             dict(

alembic/script/base.py

@@ -247,7 +247,7 @@ def _catch_revision_errors(
             raise util.CommandError(err.args[0]) from err
 
     def walk_revisions(
-        self, base: str = "base", head: str = "heads"
+        self, base: str = "base", head: str = "heads", reversed: bool = False
     ) -> Iterator[Script]:
         """Iterate through all revisions.
 
@@ -261,7 +261,11 @@ def walk_revisions(
         """
         with self._catch_revision_errors(start=base, end=head):
             for rev in self.revision_map.iterate_revisions(
-                head, base, inclusive=True, assert_relative_length=False
+                head,
+                base,
+                inclusive=True,
+                assert_relative_length=False,
+                reversed=reversed,
             ):
                 yield cast(Script, rev)
 

alembic/script/revision.py

@@ -793,6 +793,7 @@ def iterate_revisions(
         inclusive: bool = False,
         assert_relative_length: bool = True,
         select_for_downgrade: bool = False,
+        reversed: bool = False,
     ) -> Iterator[Revision]:
         """Iterate through script revisions, starting at the given
         upper revision identifier and ending at the lower.
@@ -819,7 +820,12 @@ def iterate_revisions(
             assert_relative_length=assert_relative_length,
         )
 
-        for node in self._topological_sort(revisions, heads):
+        topological_sort = (
+            self._topological_sort(revisions, heads)[::-1]
+            if reversed
+            else self._topological_sort(revisions, heads)
+        )
+        for node in topological_sort:
             yield not_none(self.get_revision(node))
 
     def _get_descendant_nodes(