Fix bug editing previous migration files. (#120)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

migration_fixer/management/commands/makemigrations.py

@@ -19,6 +19,7 @@
     get_filename,
     migration_sorter,
     no_translations,
+    sibling_nodes,
 )
 
 
@@ -161,9 +162,10 @@ def handle(self, *app_labels, **options):
                         ):
                             loader.check_consistent_history(connection)
 
-                    # Before anything else, see if there's conflicting apps and drop out
-                    # hard if there are any and they don't want to merge
-                    conflicts = loader.detect_conflicts()
+                    conflicts = {
+                        app_name: sibling_nodes(loader.graph, app_name)
+                        for app_name in loader.detect_conflicts()
+                    }
 
                     for app_label in conflicts:
                         conflict = conflicts.get(app_label)
@@ -213,8 +215,8 @@ def handle(self, *app_labels, **options):
                                     path
                                     for path in sorted_changed_files
                                     if (
-                                        int(conflict_base.split("_")[0])
-                                        >= int(get_filename(path).split("_")[0])
+                                        int(get_filename(path).split("_")[0])
+                                        >= int(conflict_base.split("_")[0])
                                     )
                                 ]
 

migration_fixer/utils.py

@@ -123,3 +123,20 @@ def wrapped(*args, **kwargs):
 def get_filename(path: str) -> str:
     """Return the file name from a path."""
     return os.path.splitext(os.path.basename(path))[0]
+
+
+def sibling_nodes(graph, app_name=None):
+    """
+    Return all sibling nodes that have the same parent
+    - it's usually the result of a VCS merge and needs some user input.
+    """
+    siblings = set()
+
+    for node in graph.nodes:
+        if len(graph.node_map[node].children) > 1 and (
+            not app_name or app_name == node[0]
+        ):
+            for child in graph.node_map[node].children:
+                siblings.add(child[-1])
+
+    return sorted(siblings)