Make questioner prompt responsive to --scriptable

django/core/management/commands/makemigrations.py

@@ -152,7 +152,9 @@ def handle(self, *app_labels, **options):
             return self.handle_merge(loader, conflicts)
 
         if self.interactive:
-            questioner = InteractiveMigrationQuestioner(specified_apps=app_labels, dry_run=self.dry_run)
+            prompt_destination = self.stderr if self.scriptable else self.stdout
+            questioner = InteractiveMigrationQuestioner(
+                specified_apps=app_labels, dry_run=self.dry_run, prompt_destination=prompt_destination)
         else:
             questioner = NonInteractiveMigrationQuestioner(specified_apps=app_labels, dry_run=self.dry_run)
         # Set up autodetector

django/db/migrations/questioner.py

@@ -81,6 +81,9 @@ def ask_auto_now_add_addition(self, field_name, model_name):
 
 
 class InteractiveMigrationQuestioner(MigrationQuestioner):
+    def __init__(self, defaults=None, specified_apps=None, dry_run=None, prompt_destination=sys.stdout):
+        super().__init__(defaults=defaults, specified_apps=specified_apps, dry_run=dry_run)
+        self.prompt_destination = prompt_destination
 
     def _boolean_input(self, question, default=None):
         result = input("%s " % question)
@@ -91,9 +94,9 @@ def _boolean_input(self, question, default=None):
         return result[0].lower() == "y"
 
     def _choice_input(self, question, choices):
-        print(question)
+        self.prompt_destination.write(question + os.linesep)
         for i, choice in enumerate(choices):
-            print(" %s) %s" % (i + 1, choice))
+            self.prompt_destination.write(" %s) %s" % (i + 1, choice) + os.linesep)
         result = input("Select an option: ")
         while True:
             try:
@@ -113,17 +116,17 @@ def _ask_default(self, default=''):
         string) which will be shown to the user and used as the return value
         if the user doesn't provide any other input.
         """
-        print('Please enter the default value as valid Python.')
+        self.prompt_destination.write('Please enter the default value as valid Python.' + os.linesep)
         if default:
-            print(
-                f"Accept the default '{default}' by pressing 'Enter' or "
-                f"provide another value."
+            self.prompt_destination.write(
+                f"Accept the default '{default}' by pressing 'Enter' or " +
+                'provide another value.' + os.linesep
             )
-        print(
+        self.prompt_destination.write(
             'The datetime and django.utils.timezone modules are available, so '
-            'it is possible to provide e.g. timezone.now as a value.'
-        )
-        print("Type 'exit' to exit this prompt")
+            'it is possible to provide e.g. timezone.now as a value.' +
+            os.linesep)
+        self.prompt_destination.write("Type 'exit' to exit this prompt" + os.linesep)
         while True:
             if default:
                 prompt = "[default: {}] >>> ".format(default)
@@ -133,14 +136,15 @@ def _ask_default(self, default=''):
             if not code and default:
                 code = default
             if not code:
-                print("Please enter some code, or 'exit' (without quotes) to exit.")
+                self.prompt_destination.write(
+                    "Please enter some code, or 'exit' (with no quotes) to exit." + os.linesep)
             elif code == "exit":
                 sys.exit(1)
             else:
                 try:
                     return eval(code, {}, {'datetime': datetime, 'timezone': timezone})
                 except (SyntaxError, NameError) as e:
-                    print("Invalid input: %s" % e)
+                    self.prompt_destination.write("Invalid input: %s" % e + os.linesep)
 
     def ask_not_null_addition(self, field_name, model_name):
         """Adding a NOT NULL field to a model."""

tests/migrations/test_commands.py

@@ -2,7 +2,6 @@
 import importlib
 import io
 import os
-import sys
 from unittest import mock
 
 from django.apps import apps
@@ -1376,9 +1375,9 @@ class Meta:
             "It is impossible to add a non-nullable field 'silly_field' to "
             "author without specifying a default. This is because the "
             "database needs something to populate existing rows.\n"
-            "Please select a fix:\n"
+            f"Please select a fix:{os.linesep}"
             " 1) Provide a one-off default now (will be set on all existing "
-            "rows with a null value for this column)\n"
+            f"rows with a null value for this column){os.linesep}"
             " 2) Quit and manually define a default value in models.py."
         )
         with self.temporary_migration_module(module='migrations.test_migrations'):
@@ -1435,13 +1434,13 @@ class Meta:
             "It is impossible to change a nullable field 'slug' on author to "
             "non-nullable without providing a default. This is because the "
             "database needs something to populate existing rows.\n"
-            "Please select a fix:\n"
+            f"Please select a fix:{os.linesep}"
             " 1) Provide a one-off default now (will be set on all existing "
-            "rows with a null value for this column)\n"
+            f"rows with a null value for this column){os.linesep}"
             " 2) Ignore for now. Existing rows that contain NULL values will "
             "have to be handled manually, for example with a RunPython or "
-            "RunSQL operation.\n"
-            " 3) Quit and manually define a default value in models.py."
+            f"RunSQL operation.{os.linesep}"
+            f" 3) Quit and manually define a default value in models.py.{os.linesep}"
         )
         with self.temporary_migration_module(module='migrations.test_migrations'):
             # 3 - quit.
@@ -1835,7 +1834,6 @@ def test_makemigrations_inconsistent_history_db_failure(self):
                 self.assertEqual(str(cm.warning), msg)
 
     @mock.patch('builtins.input', return_value='1')
-    @mock.patch('django.db.migrations.questioner.sys.stdin', mock.MagicMock(encoding=sys.getdefaultencoding()))
     def test_makemigrations_auto_now_add_interactive(self, *args):
         """
         makemigrations prompts the user when adding auto_now_add to an existing
@@ -1852,17 +1850,15 @@ class Meta:
             "It is impossible to add the field 'creation_date' with "
             "'auto_now_add=True' to entry without providing a default. This "
             "is because the database needs something to populate existing "
-            "rows.\n\n"
+            f"rows.\n{os.linesep}"
             " 1) Provide a one-off default now which will be set on all "
-            "existing rows\n"
+            f"existing rows{os.linesep}"
             " 2) Quit and manually define a default value in models.py."
         )
         # Monkeypatch interactive questioner to auto accept
         with mock.patch('django.db.migrations.questioner.sys.stdout', new_callable=io.StringIO) as prompt_stdout:
-            out = io.StringIO()
             with self.temporary_migration_module(module='migrations.test_auto_now_add'):
-                call_command('makemigrations', 'migrations', interactive=True, stdout=out)
-            output = out.getvalue()
+                call_command('makemigrations', 'migrations', interactive=True, stdout=prompt_stdout)
             prompt_output = prompt_stdout.getvalue()
             self.assertIn(input_msg, prompt_output)
             self.assertIn(
@@ -1875,7 +1871,7 @@ class Meta:
                 prompt_output,
             )
             self.assertIn("Type 'exit' to exit this prompt", prompt_output)
-            self.assertIn("Add field creation_date to entry", output)
+            self.assertIn("Add field creation_date to entry", prompt_output)
 
     @mock.patch('builtins.input', return_value='2')
     def test_makemigrations_auto_now_add_interactive_quit(self, mock_input):

tests/migrations/test_questioner.py

@@ -20,14 +20,14 @@ def test_ask_initial_with_disabled_migrations(self):
 
     @mock.patch('builtins.input', return_value='datetime.timedelta(days=1)')
     def test_timedelta_default(self, mock):
-        questioner = InteractiveMigrationQuestioner()
-        with captured_stdout():
+        with captured_stdout() as stdout:
+            questioner = InteractiveMigrationQuestioner(prompt_destination=stdout)
             value = questioner._ask_default()
         self.assertEqual(value, datetime.timedelta(days=1))
 
     @mock.patch('builtins.input', return_value='2')
     def test_ask_not_null_alteration_not_provided(self, mock):
-        questioner = InteractiveMigrationQuestioner()
-        with captured_stdout():
+        with captured_stdout() as stdout:
+            questioner = InteractiveMigrationQuestioner(prompt_destination=stdout)
             question = questioner.ask_not_null_alteration('field_name', 'model_name')
         self.assertEqual(question, NOT_PROVIDED)