Fixed #34052 -- Made migrate --check don't emit signals and output when up to date.

django/core/management/commands/migrate.py

@@ -240,23 +240,27 @@ class Command(BaseCommand):
                     self.stdout.write("  No migrations to prune.")
 
         plan = executor.migration_plan(targets)
-        exit_dry = plan and options["check_unapplied"]
 
         if options["plan"]:
             self.stdout.write("Planned operations:", self.style.MIGRATE_LABEL)
             if not plan:
                 self.stdout.write("  No planned migration operations.")
-            for migration, backwards in plan:
-                self.stdout.write(str(migration), self.style.MIGRATE_HEADING)
-                for operation in migration.operations:
-                    message, is_error = self.describe_operation(operation, backwards)
-                    style = self.style.WARNING if is_error else None
-                    self.stdout.write("    " + message, style)
-            if exit_dry:
+            else:
+                for migration, backwards in plan:
+                    self.stdout.write(str(migration), self.style.MIGRATE_HEADING)
+                    for operation in migration.operations:
+                        message, is_error = self.describe_operation(
+                            operation, backwards
+                        )
+                        style = self.style.WARNING if is_error else None
+                        self.stdout.write("    " + message, style)
+                if options["check_unapplied"]:
+                    sys.exit(1)
+            return
+        if options["check_unapplied"]:
+            if plan:
                 sys.exit(1)
             return
-        if exit_dry:
-            sys.exit(1)
         if options["prune"]:
             return
 

tests/migrate_signals/tests.py

@@ -156,3 +156,15 @@ class MigrateSignalTests(TransactionTestCase):
             ],
             ["migrate_signals.Signal"],
         )
+        # Migrating with an empty plan and --check doesn't emit signals.
+        pre_migrate_receiver = Receiver(signals.pre_migrate)
+        post_migrate_receiver = Receiver(signals.post_migrate)
+        management.call_command(
+            "migrate",
+            database=MIGRATE_DATABASE,
+            verbosity=MIGRATE_VERBOSITY,
+            interactive=MIGRATE_INTERACTIVE,
+            check_unapplied=True,
+        )
+        self.assertEqual(pre_migrate_receiver.call_counter, 0)
+        self.assertEqual(post_migrate_receiver.call_counter, 0)

tests/migrations/test_commands.py

@@ -355,6 +355,26 @@ class MigrateTests(MigrationTestBase):
         self.assertTableNotExists("migrations_tribble")
         self.assertTableNotExists("migrations_book")
 
+    @override_settings(
+        INSTALLED_APPS=[
+            "migrations.migrations_test_apps.migrated_app",
+        ]
+    )
+    def test_migrate_check_migrated_app(self):
+        out = io.StringIO()
+        try:
+            call_command("migrate", "migrated_app", verbosity=0)
+            call_command(
+                "migrate",
+                "migrated_app",
+                stdout=out,
+                check_unapplied=True,
+            )
+            self.assertEqual(out.getvalue(), "")
+        finally:
+            # Unmigrate everything.
+            call_command("migrate", "migrated_app", "zero", verbosity=0)
+
     @override_settings(
         MIGRATION_MODULES={
             "migrations": "migrations.test_migrations_plan",