Don't copy dataclass methods to the schema.

changelog.d/79.change.rst

@@ -0,0 +1 @@
+Schemas no longer copy non-field dataclass attributes. Thanks to @sveinse for report and test.

src/desert/_make.py

@@ -118,10 +118,12 @@ def class_schema(
     else:
         raise desert.exceptions.NotAnAttrsClassOrDataclass(clazz)
 
-    # Copy all public members of the dataclass to the schema
-    attributes = {k: v for k, v in inspect.getmembers(clazz) if not k.startswith("_")}
-    # Update the schema members to contain marshmallow fields instead of dataclass fields
+    # Copy all public fields of the dataclass to the schema
+    attributes = {
+        field.name: field for field in fields if not field.name.startswith("_")
+    }
 
+    # Update the schema members to contain marshmallow fields instead of dataclass fields.
     hints = t.get_type_hints(clazz)
     for field in fields:
         if field.init:

tests/test_make.py

@@ -557,3 +557,17 @@ def _(self):
 
     schema = desert.schema(C)
     assert schema.load({"x": 1}) == C(x=1, y=2)
+
+
+def test_methods_not_on_schema(module):
+    """Dataclass methods are not copied to the schema."""
+
+    @module.dataclass
+    class A:
+        def dataclass_method(self) -> None:
+            """This method should not exist on the schema."""
+
+    schema = desert.schema(A)
+    sentinel = object()
+    method = getattr(schema, "dataclass_method", sentinel)
+    assert method is sentinel