def handle_merge(self, loader, conflicts):
"""
Handles merging together conflicted migrations interactively,
if it's safe; otherwise, advises on how to fix it.
"""
if self.interactive:
questioner = InteractiveMigrationQuestioner()
else:
questioner = MigrationQuestioner(defaults={'ask_merge': True})
for app_label, migration_names in conflicts.items():
# Grab out the migrations in question, and work out their
# common ancestor.
merge_migrations = []
for migration_name in migration_names:
migration = loader.get_migration(app_label, migration_name)
migration.ancestry = [
mig for mig in loader.graph.forwards_plan((app_label, migration_name))
if mig[0] == migration.app_label
]
merge_migrations.append(migration)
def all_items_equal(seq):
return all(item == seq[0] for item in seq[1:])
merge_migrations_generations = zip(*(m.ancestry for m in merge_migrations))
common_ancestor_count = sum(1 for common_ancestor_generation
in takewhile(all_items_equal, merge_migrations_generations))
if not common_ancestor_count:
raise ValueError("Could not find common ancestor of %s" % migration_names)
# Now work out the operations along each divergent branch
for migration in merge_migrations:
migration.branch = migration.ancestry[common_ancestor_count:]
migrations_ops = (loader.get_migration(node_app, node_name).operations
for node_app, node_name in migration.branch)
migration.merged_operations = sum(migrations_ops, [])
# In future, this could use some of the Optimizer code
# (can_optimize_through) to automatically see if they're
# mergeable. For now, we always just prompt the user.
if self.verbosity > 0:
self.stdout.write(self.style.MIGRATE_HEADING("Merging %s" % app_label))
for migration in merge_migrations:
self.stdout.write(self.style.MIGRATE_LABEL(" Branch %s" % migration.name))
for operation in migration.merged_operations:
self.stdout.write(" - %s\n" % operation.describe())
if questioner.ask_merge(app_label):
# If they still want to merge it, then write out an empty
# file depending on the migrations needing merging.
numbers = [
MigrationAutodetector.parse_number(migration.name)
for migration in merge_migrations
]
try:
biggest_number = max(x for x in numbers if x is not None)
except ValueError:
biggest_number = 1
subclass = type("Migration", (Migration,), {
"dependencies": [(app_label, migration.name) for migration in merge_migrations],
})
migration_name = "%04i_%s" % (
biggest_number + 1,
self.migration_name or ("merge_%s" % get_migration_name_timestamp())
)
new_migration = subclass(migration_name, app_label)
writer = MigrationWriter(new_migration)
if not self.dry_run:
# Write the merge migrations file to the disk
with open(writer.path, "w", encoding='utf-8') as fh:
fh.write(writer.as_string())
if self.verbosity > 0:
self.stdout.write("\nCreated new merge migration %s" % writer.path)
elif self.verbosity == 3:
# Alternatively, makemigrations --merge --dry-run --verbosity 3
# will output the merge migrations to stdout rather than saving
# the file to the disk.
self.stdout.write(self.style.MIGRATE_HEADING(
"Full merge migrations file '%s':" % writer.filename) + "\n"
)
self.stdout.write("%s\n" % writer.as_string())
def __init__(self, from_state, to_state, questioner=None):
self.from_state = from_state
self.to_state = to_state
self.questioner = questioner or MigrationQuestioner()
def handle_merge(self, loader, conflicts):
"""
Handles merging together conflicted migrations interactively,
if it's safe; otherwise, advises on how to fix it.
"""
if self.interactive:
questioner = InteractiveMigrationQuestioner()
else:
questioner = MigrationQuestioner(defaults={'ask_merge': True})
for app_label, migration_names in conflicts.items():
# Grab out the migrations in question, and work out their
# common ancestor.
merge_migrations = []
for migration_name in migration_names:
migration = loader.get_migration(app_label, migration_name)
migration.ancestry = loader.graph.forwards_plan((app_label, migration_name))
merge_migrations.append(migration)
common_ancestor = None
for level in zip(*[m.ancestry for m in merge_migrations]):
if reduce(operator.eq, level):
common_ancestor = level[0]
else:
break
if common_ancestor is None:
raise ValueError("Could not find common ancestor of %s" % migration_names)
# Now work out the operations along each divergent branch
for migration in merge_migrations:
migration.branch = migration.ancestry[
(migration.ancestry.index(common_ancestor) + 1):
]
migration.merged_operations = []
for node_app, node_name in migration.branch:
migration.merged_operations.extend(
loader.get_migration(node_app, node_name).operations
)
# In future, this could use some of the Optimizer code
# (can_optimize_through) to automatically see if they're
# mergeable. For now, we always just prompt the user.
if self.verbosity > 0:
self.stdout.write(self.style.MIGRATE_HEADING("Merging %s" % app_label))
for migration in merge_migrations:
self.stdout.write(self.style.MIGRATE_LABEL(" Branch %s" % migration.name))
for operation in migration.merged_operations:
self.stdout.write(" - %s\n" % operation.describe())
if questioner.ask_merge(app_label):
# If they still want to merge it, then write out an empty
# file depending on the migrations needing merging.
numbers = [
MigrationAutodetector.parse_number(migration.name)
for migration in merge_migrations
]
try:
biggest_number = max([x for x in numbers if x is not None])
except ValueError:
biggest_number = 1
subclass = type("Migration", (Migration, ), {
"dependencies": [(app_label, migration.name) for migration in merge_migrations],
})
new_migration = subclass("%04i_merge" % (biggest_number + 1), app_label)
writer = MigrationWriter(new_migration)
if not self.dry_run:
# Write the merge migrations file to the disk
with open(writer.path, "wb") as fh:
fh.write(writer.as_string())
if self.verbosity > 0:
self.stdout.write("\nCreated new merge migration %s" % writer.path)
elif self.verbosity == 3:
# Alternatively, makemigrations --merge --dry-run --verbosity 3
# will output the merge migrations to stdout rather than saving
# the file to the disk.
self.stdout.write(self.style.MIGRATE_HEADING(
"Full merge migrations file '%s':" % writer.filename) + "\n"
)
self.stdout.write("%s\n" % writer.as_string())
def test_ask_not_null_alteration(self):
questioner = MigrationQuestioner()
self.assertIsNone(questioner.ask_not_null_alteration('field_name', 'model_name'))
def test_ask_initial_with_disabled_migrations(self):
questioner = MigrationQuestioner()
self.assertIs(False, questioner.ask_initial('migrations'))
def __init__(self, from_state, to_state, questioner=None):
self.from_state = from_state
self.to_state = to_state
self.questioner = questioner or MigrationQuestioner()
self.existing_apps = {app for app, model in from_state.models}
