Add test

tests/test_field_cfg.rs

@@ -0,0 +1,24 @@
+#![cfg(feature = "macros")]
+
+use pyo3::prelude::*;
+
+#[pyclass]
+struct CfgClass {
+    #[pyo3(get, set)]
+    #[cfg(any())]
+    pub a: u32,
+    #[pyo3(get, set)]
+    #[cfg(all())]
+    pub b: u32,
+}
+
+#[test]
+fn test_cfg() {
+    Python::with_gil(|py| {
+        let cfg = CfgClass { b: 3 };
+        let py_cfg = Py::new(py, cfg).unwrap();
+        assert!(py_cfg.as_ref(py).getattr("a").is_err());
+        let b: u32 = py_cfg.as_ref(py).getattr("b").unwrap().extract().unwrap();
+        assert_eq!(b, 3);
+    });
+}