modified _create_new_migration to return info about the created file

This will be useful for testing purposes.

Author: dantownsend

piccolo/apps/migrations/commands/new.py

@@ -1,4 +1,5 @@
 from __future__ import annotations
+from dataclasses import dataclass
 import datetime
 from itertools import chain
 import os
@@ -52,7 +53,16 @@ def _create_migrations_folder(migrations_path: str) -> bool:
         return True
 
 
-async def _create_new_migration(app_config: AppConfig, auto=False) -> None:
+@dataclass
+class NewMigrationMeta:
+    migration_id: str
+    migration_filename: str
+    migration_path: str
+
+
+async def _create_new_migration(
+    app_config: AppConfig, auto=False
+) -> NewMigrationMeta:
     """
     Creates a new migration file on disk.
     """
@@ -105,6 +115,10 @@ async def _create_new_migration(app_config: AppConfig, auto=False) -> None:
     with open(path, "w") as f:
         f.write(file_contents)
 
+    return NewMigrationMeta(
+        migration_id=_id, migration_filename=filename, migration_path=path
+    )
+
 
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