feature: fixes #87 drop_unused_enums, detect_enum_values_changes feature flags that can be disabled

README.md

@@ -30,33 +30,19 @@ import alembic_postgresql_enum
 
 To the top of your migrations/env.py file.
 
-## Configuration
-
-You can configure this extension to disable parts of it, or to enable some feature flags
-
-To do so you need to call set_configuration function after the import:
-
-```python
-import alembic_postgresql_enum
-
-alembic_postgresql_enum.set_configuration(
-    alembic_postgresql_enum.Config(
-        add_type_ignore=True,
-    )
-)
-```
 ## Features
 
 * [Creation of enums](#creation-of-enum)
 * [Deletion of unreferenced enums](#deletion-of-unreferenced-enum)
-* [Creation of new enum values](#creation-of-new-enum-values)
-* [Deletion of enums values](#deletion-of-enums-values)
-* [Renaming of enum values](#rename-enum-value)
+* [Detection of enum values changes](#detection-of-enum-values-changes)
+  * [Creation of new enum values](#creation-of-new-enum-values)
+  * [Deletion of enums values](#deletion-of-enums-values)
+  * [Renaming of enum values](#rename-enum-value)
 * [Omitting managing enums](#omitting-managing-enums)
 
-### Creation of enum<a id="creation-of-enum"></a>
+## Creation of enum<a id="creation-of-enum"></a>
 
-#### When table is created
+### When table is created
 
 ```python
 class MyEnum(enum.Enum):
@@ -93,7 +79,7 @@ def downgrade():
     # ### end Alembic commands ###
 ```
 
-#### When column is added
+### When column is added
 ```python
 class MyEnum(enum.Enum):
     one = 1
@@ -125,7 +111,7 @@ def downgrade():
     # ### end Alembic commands ###
 ```
 
-### Deletion of unreferenced enum<a id="deletion-of-unreferenced-enum"></a>
+## Deletion of unreferenced enum<a id="deletion-of-unreferenced-enum"></a>
 If enum is defined in postgres schema, but its mentions removed from code - It will be automatically removed
 ```python
 class ExampleTable(BaseModel):
@@ -148,6 +134,10 @@ def downgrade():
     # ### end Alembic commands ###
 ```
 
+## Detection of enum values changes<a id="detection-of-enum-values-changes"></a>
+
+***Can be disabled with `detect_enum_values_changes` configuration flag turned off***
+
 ### Creation of new enum values<a id="creation-of-new-enum-values"></a>
 
 If new enum value is defined sync_enum_values function call will be added to migration to account for it
@@ -221,6 +211,7 @@ def downgrade():
     # ### end Alembic commands ###
 ```
 
+
 ### Rename enum value<a id="rename-enum-value"></a>
 In this case you must manually edit migration
 
@@ -286,7 +277,7 @@ Do not forget to switch places old and new values for downgrade
 
 All defaults in postgres will be renamed automatically as well
 
-### Omitting managing enums<a id="omitting-managing-enums"></a>
+## Omitting managing enums<a id="omitting-managing-enums"></a>
 
 If configured `include_name` function returns `False` given enum will be not managed.
 ```python
@@ -302,4 +293,34 @@ alembic_postgresql_enum.set_configuration(
 )
 ```
 
-Feature is similar to [sqlalchemy feature for tables](https://alembic.sqlalchemy.org/en/latest/autogenerate.html#omitting-table-names-from-the-autogenerate-process)
+Feature is similar to [sqlalchemy feature for tables](https://alembic.sqlalchemy.org/en/latest/autogenerate.html#omitting-table-names-from-the-autogenerate-process)
+
+## Configuration
+
+You can configure this extension to disable parts of it, or to enable some feature flags
+
+To do so you need to call set_configuration function after the import:
+
+```python
+import alembic_postgresql_enum
+
+alembic_postgresql_enum.set_configuration(
+    alembic_postgresql_enum.Config(
+        add_type_ignore=True,
+    )
+)
+```
+
+Available options:
+
+- `add_type_ignore` (`False` by default) - flag that can be turned on 
+to add `# type: ignore[attr-defined]` at the end of generated `op.sync_enum_values` calls.
+This is helpful if you are using type checker such as `mypy`.
+`type: ignore` is needed because there is no way to add new function to an existing alembic's `op`.
+
+- `include_name` (`lambda _: True` bby default) - it adds ability to ignore process enum by name in similar way alembic allows to define `include_name` function. 
+This property accepts function that takes enum name and returns whether it should be processed.  
+
+- `drop_unused_enums` (`True` by default) - feature flag that can be turned off to disable clean up of undeclared enums
+
+- `detect_enum_values_changes` (`True` by default) - feature flag that can be turned off to disable generation of `op.sync_enum_values`.

alembic_postgresql_enum/compare_dispatch.py

@@ -76,12 +76,14 @@ def compare_enums(
 
         create_new_enums(definitions, declarations.enum_values, schema, upgrade_ops)
 
-        drop_unused_enums(definitions, declarations.enum_values, schema, upgrade_ops)
-
-        sync_changed_enums(
-            definitions,
-            declarations.enum_values,
-            declarations.enum_table_references,
-            schema,
-            upgrade_ops,
-        )
+        if configuration.drop_unused_enums:
+            drop_unused_enums(definitions, declarations.enum_values, schema, upgrade_ops)
+
+        if configuration.detect_enum_values_changes:
+            sync_changed_enums(
+                definitions,
+                declarations.enum_values,
+                declarations.enum_table_references,
+                schema,
+                upgrade_ops,
+            )

alembic_postgresql_enum/configuration.py

@@ -6,6 +6,8 @@
 class Config:
     add_type_ignore: bool = False
     include_name: Callable[[str], bool] = lambda _: True
+    drop_unused_enums: bool = True
+    detect_enum_values_changes: bool = True
 
 
 _config = Config()

alembic_postgresql_enum/sql_commands/column_default.py

@@ -66,7 +66,6 @@ def rename_default_if_required(
         return column_default_value
 
     if default_value.endswith("[]"):
-
         # remove old type postfix
         column_default_value = default_value[: default_value.find("::")]
 

tests/sync_enum_values/test_render.py

@@ -26,6 +26,37 @@
 from tests.utils.migration_context import create_migration_context
 
 
+class TestDisabledSyncEnumValues(CompareAndRunTestCase):
+    """Check that enum variants are updated when new variant is added"""
+
+    config = Config(detect_enum_values_changes=False)
+
+    old_enum_variants = ["active", "passive"]
+    new_enum_variants = old_enum_variants + ["banned"]
+
+    def get_database_schema(self) -> MetaData:
+        schema = get_schema_with_enum_variants(self.old_enum_variants)
+        return schema
+
+    def get_target_schema(self) -> MetaData:
+        schema = get_schema_with_enum_variants(self.new_enum_variants)
+        return schema
+
+    def get_expected_upgrade(self) -> str:
+        return f"""
+        # ### commands auto generated by Alembic - please adjust! ###
+        pass
+        # ### end Alembic commands ###
+        """
+
+    def get_expected_downgrade(self) -> str:
+        return f"""
+        # ### commands auto generated by Alembic - please adjust! ###
+        pass
+        # ### end Alembic commands ###
+        """
+
+
 class TestAddNewEnumValueRender(CompareAndRunTestCase):
     """Check that enum variants are updated when new variant is added"""
 

tests/test_enum_creation/test_drop_column.py

@@ -1,5 +1,6 @@
 from typing import TYPE_CHECKING
 
+from alembic_postgresql_enum import Config
 from alembic_postgresql_enum.operations import DropEnumOp
 from tests.base.run_migration_test_abc import CompareAndRunTestCase
 
@@ -63,6 +64,36 @@ def get_expected_downgrade(self) -> str:
         """
 
 
+class TestDisabledDeleteEnumAfterDropColumn(CompareAndRunTestCase):
+    """Check that library correctly removes unused enum after drop_column"""
+
+    config = Config(
+        drop_unused_enums=False,
+    )
+    enum_variants_to_delete = ["active", "passive"]
+
+    def get_database_schema(self) -> MetaData:
+        return get_schema_with_enum_variants(self.enum_variants_to_delete)
+
+    def get_target_schema(self) -> MetaData:
+        return get_schema_without_enum()
+
+    def get_expected_upgrade(self) -> str:
+        return f"""
+        # ### commands auto generated by Alembic - please adjust! ###
+        op.drop_column('{USER_TABLE_NAME}', '{USER_STATUS_COLUMN_NAME}')
+        # ### end Alembic commands ###
+        """
+
+    def get_expected_downgrade(self) -> str:
+        # For some reason alembic decided to add redundant autoincrement=False on downgrade
+        return f"""
+        # ### commands auto generated by Alembic - please adjust! ###
+        op.add_column('{USER_TABLE_NAME}', sa.Column('{USER_STATUS_COLUMN_NAME}', postgresql.ENUM({', '.join(map(repr, self.enum_variants_to_delete))}, name='{USER_STATUS_ENUM_NAME}', create_type=False), autoincrement=False, nullable=True))
+        # ### end Alembic commands ###
+        """
+
+
 class TestDeleteEnumAfterDropColumnWithArray(CompareAndRunTestCase):
     """Check that library correctly removes unused enum after drop_column. Enum is used in ARRAY"""