[1.7.x] Fixed #22862 -- Added --noinput option to makemigrations.

Thanks artortenburger for the report.

Backport of fbb684d95e from master

django/core/management/commands/makemigrations.py

@@ -22,6 +22,8 @@ class Command(BaseCommand):
             help="Enable fixing of migration conflicts."),
         make_option('--empty', action='store_true', dest='empty', default=False,
             help="Create an empty migration."),
+        make_option('--noinput', action='store_false', dest='interactive', default=True,
+            help='Tells Django to NOT prompt the user for input of any kind.'),
     )
 
     help = "Creates new migration(s) for apps."
@@ -156,7 +158,7 @@ class Command(BaseCommand):
         if self.interactive:
             questioner = InteractiveMigrationQuestioner()
         else:
-            questioner = MigrationQuestioner()
+            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.

docs/ref/django-admin.txt

@@ -642,6 +642,8 @@ Providing one or more app names as arguments will limit the migrations created
 to the app(s) specified and any dependencies needed (the table at the other end
 of a ``ForeignKey``, for example).
 
+The :djadminopt:`--noinput` option may be provided to suppress all user prompts.
+
 .. django-admin-option:: --empty
 
 The ``--empty`` option will cause ``makemigrations`` to output an empty

tests/migrations/test_commands.py

@@ -231,19 +231,6 @@ class MakeMigrationsTests(MigrationTestBase):
         with self.assertRaises(CommandError):
             call_command("makemigrations")
 
-    @override_system_checks([])
-    @override_settings(MIGRATION_MODULES={"migrations": "migrations.test_migrations_conflict"})
-    def test_makemigrations_merge_basic(self):
-        """
-        Makes sure that makemigrations doesn't error if you ask for
-        merge mode with a conflict present. Doesn't test writing of the merge
-        file, as that requires temp directories.
-        """
-        try:
-            call_command("makemigrations", merge=True, verbosity=0)
-        except CommandError:
-            self.fail("Makemigrations errored in merge mode with conflicts")
-
     @override_system_checks([])
     @override_settings(MIGRATION_MODULES={"migrations": "migrations.test_migrations"})
     def test_makemigrations_merge_no_conflict(self):
@@ -386,13 +373,18 @@ class MakeMigrationsTests(MigrationTestBase):
     @override_settings(MIGRATION_MODULES={"migrations": "migrations.test_migrations_conflict"})
     def test_makemigrations_handle_merge(self):
         """
-        Makes sure that makemigrations properly merges the conflicting migrations.
+        Makes sure that makemigrations properly merges the conflicting migrations with --noinput.
         """
         stdout = six.StringIO()
-        call_command("makemigrations", "migrations", merge=True, stdout=stdout)
+        call_command("makemigrations", "migrations", merge=True, interactive=False, stdout=stdout)
         self.assertIn("Merging migrations", stdout.getvalue())
         self.assertIn("Branch 0002_second", stdout.getvalue())
         self.assertIn("Branch 0002_conflicting_second", stdout.getvalue())
+        merge_file = os.path.join(self.test_dir, 'test_migrations_conflict', '0003_merge.py')
+        self.assertTrue(os.path.exists(merge_file))
+        os.remove(merge_file)
+        self.assertFalse(os.path.exists(merge_file))
+        self.assertIn("Created new merge migration", stdout.getvalue())
 
     @override_system_checks([])
     @override_settings(MIGRATION_MODULES={"migrations": "migrations.test_migrations_no_default"})
@@ -469,3 +461,28 @@ class MakeMigrationsTests(MigrationTestBase):
         self.assertTrue(os.path.isfile(os.path.join(self.test_dir,
                        "test_migrations_path_doesnt_exist", "foo", "bar",
                        "0001_initial.py")))
+
+    @override_system_checks([])
+    @override_settings(MIGRATION_MODULES={"migrations": "migrations.test_migrations_conflict"})
+    def test_makemigrations_interactive_by_default(self):
+        """
+        Makes sure that the user is prompted to merge by default if there are
+        conflicts and merge is True. Answer negative to differentiate it from
+        behavior when --noinput is specified.
+        """
+        # Monkeypatch interactive questioner to auto reject
+        old_input = questioner.input
+        questioner.input = lambda _: "N"
+        stdout = six.StringIO()
+        merge_file = os.path.join(self.test_dir, 'test_migrations_conflict', '0003_merge.py')
+        try:
+            call_command("makemigrations", "migrations", merge=True, stdout=stdout)
+            # This will fail if interactive is False by default
+            self.assertFalse(os.path.exists(merge_file))
+        except CommandError:
+            self.fail("Makemigrations failed while running interactive questioner")
+        finally:
+            questioner.input = old_input
+            if os.path.exists(merge_file):
+                os.remove(merge_file)
+        self.assertNotIn("Created new merge migration", stdout.getvalue())