Fix overlapping, missing slots

piccolo/columns/combination.py

@@ -12,6 +12,9 @@
 
 
 class CombinableMixin(object):
+
+    __slots__ = ()
+
     def __and__(self, value: Combinable) -> "And":
         return And(self, value)  # type: ignore
 
@@ -86,6 +89,8 @@ class Undefined:
 
 
 class WhereRaw(CombinableMixin):
+    __slots__ = ("querystring",)
+
     def __init__(self, sql: str, *args: t.Any) -> None:
         """
         Execute raw SQL queries in your where clause. Use with caution!

piccolo/query/methods/alter.py

@@ -72,7 +72,7 @@ def ddl(self) -> str:
 
 @dataclass
 class AddColumn(AlterColumnStatement):
-    __slots__ = ("column", "name")
+    __slots__ = ("name",)
 
     column: Column
     name: str
@@ -120,7 +120,7 @@ def ddl(self) -> str:
 
 @dataclass
 class SetDefault(AlterColumnStatement):
-    __slots__ = ("column", "value")
+    __slots__ = ("value",)
 
     column: Column
     value: t.Any

requirements/dev-requirements.txt

@@ -3,6 +3,7 @@ ipdb==0.13.9
 ipython>=7.31.1
 flake8==4.0.1
 isort==5.10.1
+slotscheck==0.12.0
 twine==3.7.1
 mypy==0.931
 pip-upgrader==1.4.15

scripts/lint.sh

@@ -1,7 +1,8 @@
 #!/bin/bash
 set -e
 
-SOURCES="piccolo tests"
+MODULES="piccolo"
+SOURCES="$MODULES tests"
 
 echo "Running isort..."
 isort --check $SOURCES
@@ -19,4 +20,8 @@ echo "Running mypy..."
 mypy $SOURCES
 echo "-----"
 
+echo "Running slotscheck..."
+python -m slotscheck $MODULES
+echo "-----"
+
 echo "All passed!"