Fixes opentofu#539: Setting both "Type" and "NestedType" removes othe…

…r validation error messages (opentofu#897)

Signed-off-by: Janos Bonic <86970079+janosdebugs@users.noreply.github.com>

internal/configs/configschema/internal_validate.go

@@ -128,7 +128,7 @@ func (a *Attribute) internalValidate(name, prefix string) error {
 
 	if a.Type != cty.NilType {
 		if a.NestedType != nil {
-			err = multierror.Append(fmt.Errorf("%s: Type and NestedType cannot both be set", name))
+			err = multierror.Append(err, fmt.Errorf("%s: Type and NestedType cannot both be set", name))
 		}
 	}
 

internal/configs/configschema/internal_validate_test.go

@@ -134,6 +134,32 @@ func TestBlockInternalValidate(t *testing.T) {
 			},
 			[]string{"foo: either Type or NestedType must be defined"},
 		},
+		"attribute with both type and nestedtype should not suppress other validation messages": {
+			&Block{
+				Attributes: map[string]*Attribute{
+					"foo": {
+						// These properties are here to make sure other errors are also reported.
+						Optional: true,
+						Required: true,
+						// Here's what we actually want to validate:
+						Type: cty.String,
+						NestedType: &Object{
+							Nesting: NestingSingle,
+							Attributes: map[string]*Attribute{
+								"foo": {
+									Type:     cty.String,
+									Required: true,
+								},
+							},
+						},
+					},
+				},
+			},
+			[]string{
+				"foo: cannot set both Optional and Required",
+				"foo: Type and NestedType cannot both be set",
+			},
+		},
 		/* FIXME: This caused errors when applied to existing providers (oci)
 		and cannot be enforced without coordination.