x

core/mapping/unmarshaler_test.go

@@ -4425,4 +4425,16 @@ func TestFillDefaultUnmarshal(t *testing.T) {
 		assert.Equal(t, st.A, "a")
 		assert.Equal(t, st.C, "c")
 	})
+
+	t.Run("has value", func(t *testing.T) {
+		type St struct {
+			A string `json:",default=a"`
+			B string
+		}
+		var st = St{
+			A: "b",
+		}
+		err := fillDefaultUnmarshal.Unmarshal(map[string]any{}, &st)
+		assert.Error(t, err)
+	})
 }