Add unit test for module

tests/test_module.rs

@@ -0,0 +1,50 @@
+#![feature(proc_macro, specialization)]
+
+#[macro_use]
+extern crate pyo3;
+
+use pyo3::{PyDict, PyModule, PyObject, PyResult, Python};
+use pyo3::py::{class, function, modinit};
+
+
+#[class]
+struct EmptyClass {}
+
+fn sum_as_string(a: i64, b: i64) -> String {
+    format!("{}", a + b).to_string()
+}
+
+/// This module is implemented in Rust.
+#[modinit(module_with_functions)]
+fn init_mod(py: Python, m: &PyModule) -> PyResult<()> {
+    #[pyfn(m, "sum_as_string")]
+    fn sum_as_string_py(_py: Python, a: i64, b: i64) -> PyResult<String> {
+        let out = sum_as_string(a, b);
+        return Ok(out);
+    }
+
+    #[pyfn(m, "no_parameters")]
+    fn no_parameters() -> PyResult<usize> {
+        return Ok(42);
+    }
+
+    m.add_class::<EmptyClass>();
+
+    m.add("foo", "bar");
+
+    Ok(())
+}
+
+#[test]
+fn test_module_with_functions() {
+    let gil = Python::acquire_gil();
+    let py = gil.python();
+
+    let d = PyDict::new(py);
+    d.set_item("module_with_functions", unsafe { PyObject::from_owned_ptr(py, PyInit_module_with_functions()) }).unwrap();
+    py.run("assert module_with_functions.__doc__.strip() == 'This module is implemented in Rust.'", None, Some(d)).unwrap();
+    py.run("assert module_with_functions.sum_as_string(1, 2) == '3'", None, Some(d)).unwrap();
+    py.run("assert module_with_functions.no_parameters() == 42", None, Some(d)).unwrap();
+    py.run("assert module_with_functions.foo == 'bar'", None, Some(d)).unwrap();
+    py.run("assert module_with_functions.EmptyClass != None", None, Some(d)).unwrap();
+}