Fixed #32900 -- Improved migrations questioner prompts.

2 files changed, 64 insertions, 50 deletions

diff --git a/django/db/migrations/questioner.py b/django/db/migrations/questioner.py
index 216f2af6a1..3891616ce0 100644
--- a/django/db/migrations/questioner.py
+++ b/django/db/migrations/questioner.py
@@ -71,7 +71,7 @@ class MigrationQuestioner:
         return self.defaults.get("ask_rename_model", False)
 
     def ask_merge(self, app_label):
-        """Do you really want to merge these migrations?"""
+        """Should these migrations really be merged?"""
         return self.defaults.get("ask_merge", False)
 
     def ask_auto_now_add_addition(self, field_name, model_name):
@@ -113,13 +113,16 @@ class InteractiveMigrationQuestioner(MigrationQuestioner):
         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 now, as valid Python")
+        print('Please enter the default value as valid Python.')
         if default:
             print(
-                "You can accept the default '{}' by pressing 'Enter' or you "
-                "can provide another value.".format(default)
+                f"Accept the default '{default}' by pressing 'Enter' or "
+                f"provide another value."
             )
-        print("The datetime and django.utils.timezone modules are available, so you can do e.g. timezone.now")
+        print(
+            '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")
         while True:
             if default:
@@ -130,7 +133,7 @@ class InteractiveMigrationQuestioner(MigrationQuestioner):
             if not code and default:
                 code = default
             if not code:
-                print("Please enter some code, or 'exit' (with no quotes) to exit.")
+                print("Please enter some code, or 'exit' (without quotes) to exit.")
             elif code == "exit":
                 sys.exit(1)
             else:
@@ -143,13 +146,15 @@ class InteractiveMigrationQuestioner(MigrationQuestioner):
         """Adding a NOT NULL field to a model."""
         if not self.dry_run:
             choice = self._choice_input(
-                "You are trying to add a non-nullable field '%s' to %s without a default; "
-                "we can't do that (the database needs something to populate existing rows).\n"
-                "Please select a fix:" % (field_name, model_name),
+                f"It is impossible to add a non-nullable field '{field_name}' "
+                f"to {model_name} without specifying a default. This is "
+                f"because the database needs something to populate existing "
+                f"rows.\n"
+                f"Please select a fix:",
                 [
                     ("Provide a one-off default now (will be set on all existing "
                      "rows with a null value for this column)"),
-                    "Quit, and let me add a default in models.py",
+                    'Quit and manually define a default value in models.py.',
                 ]
             )
             if choice == 2:
@@ -162,17 +167,18 @@ class InteractiveMigrationQuestioner(MigrationQuestioner):
         """Changing a NULL field to NOT NULL."""
         if not self.dry_run:
             choice = self._choice_input(
-                "You are trying to change the nullable field '%s' on %s to non-nullable "
-                "without a default; we can't do that (the database needs something to "
-                "populate existing rows).\n"
-                "Please select a fix:" % (field_name, model_name),
+                f"It is impossible to change a nullable field '{field_name}' "
+                f"on {model_name} to non-nullable without providing a "
+                f"default. This is because the database needs something to "
+                f"populate existing rows.\n"
+                f"Please select a fix:",
                 [
                     ("Provide a one-off default now (will be set on all existing "
                      "rows with a null value for this column)"),
-                    ("Ignore for now, and let me handle existing rows with NULL myself "
-                     "(e.g. because you added a RunPython or RunSQL operation to handle "
-                     "NULL values in a previous data migration)"),
-                    "Quit, and let me add a default in models.py",
+                    'Ignore for now. Existing rows that contain NULL values '
+                    'will have to be handled manually, for example with a '
+                    'RunPython or RunSQL operation.',
+                    'Quit and manually define a default value in models.py.',
                 ]
             )
             if choice == 2:
@@ -185,13 +191,13 @@ class InteractiveMigrationQuestioner(MigrationQuestioner):
 
     def ask_rename(self, model_name, old_name, new_name, field_instance):
         """Was this field really renamed?"""
-        msg = "Did you rename %s.%s to %s.%s (a %s)? [y/N]"
+        msg = 'Was %s.%s renamed to %s.%s (a %s)? [y/N]'
         return self._boolean_input(msg % (model_name, old_name, model_name, new_name,
                                           field_instance.__class__.__name__), False)
 
     def ask_rename_model(self, old_model_state, new_model_state):
         """Was this model really renamed?"""
-        msg = "Did you rename the %s.%s model to %s? [y/N]"
+        msg = 'Was the model %s.%s renamed to %s? [y/N]'
         return self._boolean_input(msg % (old_model_state.app_label, old_model_state.name,
                                           new_model_state.name), False)
 
@@ -199,7 +205,7 @@ class InteractiveMigrationQuestioner(MigrationQuestioner):
         return self._boolean_input(
             "\nMerging will only work if the operations printed above do not conflict\n" +
             "with each other (working on different fields or models)\n" +
-            "Do you want to merge these migration branches? [y/N]",
+            'Should these migration branches be merged?',
             False,
         )
 
@@ -207,13 +213,14 @@ class InteractiveMigrationQuestioner(MigrationQuestioner):
         """Adding an auto_now_add field to a model."""
         if not self.dry_run:
             choice = self._choice_input(
-                "You are trying to add the field '{}' with 'auto_now_add=True' "
-                "to {} without a default; the database needs something to "
-                "populate existing rows.\n".format(field_name, model_name),
+                f"It is impossible to add the field '{field_name}' with "
+                f"'auto_now_add=True' to {model_name} without providing a "
+                f"default. This is because the database needs something to "
+                f"populate existing rows.\n",
                 [
-                    "Provide a one-off default now (will be set on all "
-                    "existing rows)",
-                    "Quit, and let me add a default in models.py",
+                    'Provide a one-off default now which will be set on all '
+                    'existing rows',
+                    'Quit and manually define a default value in models.py.',
                 ]
             )
             if choice == 2:
diff --git a/tests/migrations/test_commands.py b/tests/migrations/test_commands.py
index 133df37c06..563b1bd146 100644
--- a/tests/migrations/test_commands.py
+++ b/tests/migrations/test_commands.py
@@ -1360,13 +1360,13 @@ class MakeMigrationsTests(MigrationTestBase):
                 app_label = 'migrations'
 
         input_msg = (
-            "You are trying to add a non-nullable field 'silly_field' to "
-            "author without a default; we can't do that (the database needs "
-            "something to populate existing rows).\n"
+            "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"
             " 1) Provide a one-off default now (will be set on all existing "
             "rows with a null value for this column)\n"
-            " 2) Quit, and let me add a default in models.py"
+            " 2) Quit and manually define a default value in models.py."
         )
         with self.temporary_migration_module(module='migrations.test_migrations'):
             # 2 - quit.
@@ -1380,10 +1380,11 @@ class MakeMigrationsTests(MigrationTestBase):
                     call_command('makemigrations', 'migrations', interactive=True)
             output = out.getvalue()
             self.assertIn(input_msg, output)
-            self.assertIn('Please enter the default value now, as valid Python', output)
+            self.assertIn('Please enter the default value as valid Python.', output)
             self.assertIn(
                 'The datetime and django.utils.timezone modules are '
-                'available, so you can do e.g. timezone.now',
+                'available, so it is possible to provide e.g. timezone.now as '
+                'a value',
                 output,
             )
             self.assertIn("Type 'exit' to exit this prompt", output)
@@ -1418,16 +1419,16 @@ class MakeMigrationsTests(MigrationTestBase):
                 app_label = 'migrations'
 
         input_msg = (
-            "You are trying to change the nullable field 'slug' on author to "
-            "non-nullable without a default; we can't do that (the database "
-            "needs something to populate existing rows).\n"
+            "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"
             " 1) Provide a one-off default now (will be set on all existing "
             "rows with a null value for this column)\n"
-            " 2) Ignore for now, and let me handle existing rows with NULL "
-            "myself (e.g. because you added a RunPython or RunSQL operation "
-            "to handle NULL values in a previous data migration)\n"
-            " 3) Quit, and let me add a default in models.py"
+            " 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."
         )
         with self.temporary_migration_module(module='migrations.test_migrations'):
             # 3 - quit.
@@ -1441,10 +1442,11 @@ class MakeMigrationsTests(MigrationTestBase):
                     call_command('makemigrations', 'migrations', interactive=True)
             output = out.getvalue()
             self.assertIn(input_msg, output)
-            self.assertIn('Please enter the default value now, as valid Python', output)
+            self.assertIn('Please enter the default value as valid Python.', output)
             self.assertIn(
                 'The datetime and django.utils.timezone modules are '
-                'available, so you can do e.g. timezone.now',
+                'available, so it is possible to provide e.g. timezone.now as '
+                'a value',
                 output,
             )
             self.assertIn("Type 'exit' to exit this prompt", output)
@@ -1814,12 +1816,13 @@ class MakeMigrationsTests(MigrationTestBase):
                 app_label = 'migrations'
 
         input_msg = (
-            "You are trying to add the field 'creation_date' with "
-            "'auto_now_add=True' to entry without a default; the database "
-            "needs something to populate existing rows.\n\n"
-            " 1) Provide a one-off default now (will be set on all existing "
-            "rows)\n"
-            " 2) Quit, and let me add a default in models.py"
+            "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"
+            " 1) Provide a one-off default now which will be set on all "
+            "existing rows\n"
+            " 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:
@@ -1830,10 +1833,14 @@ class MakeMigrationsTests(MigrationTestBase):
             prompt_output = prompt_stdout.getvalue()
             self.assertIn(input_msg, prompt_output)
             self.assertIn(
-                'Please enter the default value now, as valid Python',
+                'Please enter the default value as valid Python.',
+                prompt_output,
+            )
+            self.assertIn(
+                "Accept the default 'timezone.now' by pressing 'Enter' or "
+                "provide another value.",
                 prompt_output,
             )
-            self.assertIn("You can accept the default 'timezone.now' by pressing 'Enter'", prompt_output)
             self.assertIn("Type 'exit' to exit this prompt", prompt_output)
             self.assertIn("Add field creation_date to entry", output)