Add a generate_python_tests! macro (#91)

The macro generates tests for Python scripts found next to the
integration test.

This saves a bit of boiler-plate code at the point where the test is
created. It also allows us to quickly see if there are gaps in the
test coverage between the sync and async code.

This comes at the expense of more “magic” in the form of the macro.

mls-rs-uniffi/Cargo.toml

@@ -27,5 +27,4 @@ uniffi = "0.26.0"
 tokio = { version = "1.36.0", features = ["sync"] }
 
 [dev-dependencies]
-tempfile = "3.10.0"
 uniffi_bindgen = "0.26.0"

mls-rs-uniffi/src/lib.rs

@@ -18,8 +18,6 @@
 //! [UniFFI]: https://mozilla.github.io/uniffi-rs/
 
 mod config;
-#[cfg(test)]
-pub mod test_utils;
 
 use std::sync::Arc;
 
@@ -597,31 +595,3 @@ impl Group {
         }
     }
 }
-
-#[cfg(all(test, not(mls_build_async)))]
-mod sync_tests {
-    use crate::test_utils::run_python;
-
-    #[test]
-    fn test_generate_signature_keypair() -> Result<(), Box<dyn std::error::Error>> {
-        run_python(include_str!("../test_bindings/signatures_sync.py"))
-    }
-
-    #[test]
-    fn test_simple_scenario() -> Result<(), Box<dyn std::error::Error>> {
-        run_python(include_str!("../test_bindings/simple_scenario_sync.py"))
-    }
-}
-
-// TODO(mulmarta): it'll break if we use async trait which will be supported in
-// the next UniFFI release
-#[cfg(all(test, mls_build_async))]
-mod async_tests {
-    use crate::test_utils::run_python;
-
-    #[ignore]
-    #[test]
-    fn test_simple_scenario() -> Result<(), Box<dyn std::error::Error>> {
-        run_python(include_str!("../test_bindings/simple_scenario_async.py"))
-    }
-}

mls-rs-uniffi/tests/scenarios.rs

@@ -0,0 +1,50 @@
+/// Run sync and async Python scenarios.
+///
+/// The Python scripts are given as identifiers, relative to this
+/// file. They can be `None` if the sync or async test variant does
+/// not exist.
+///
+/// The test script can use `import mls_rs_uniffi` to get access to
+/// the Python bindings.
+macro_rules! generate_python_tests {
+    ($sync_scenario:ident, None) => {
+        #[cfg(not(mls_build_async))]
+        generate_python_tests!($sync_scenario);
+    };
+
+    (None, $async_scenario:ident) => {
+        #[cfg(mls_build_async)]
+        generate_python_tests!($async_scenario);
+    };
+
+    ($sync_scenario:ident, $async_scenario:ident) => {
+        #[cfg(not(mls_build_async))]
+        generate_python_tests!($sync_scenario);
+
+        #[cfg(mls_build_async)]
+        generate_python_tests!($async_scenario);
+    };
+
+    ($scenario:ident) => {
+        #[test]
+        fn $scenario() -> Result<(), Box<dyn std::error::Error>> {
+            let target_dir = env!("CARGO_TARGET_TMPDIR");
+            let script_path = format!("tests/{}.py", stringify!($scenario));
+            uniffi_bindgen::bindings::python::run_script(
+                &target_dir,
+                "mls-rs-uniffi",
+                &script_path,
+                vec![],
+                &uniffi_bindgen::bindings::RunScriptOptions::default(),
+            )
+            .map_err(Into::into)
+        }
+    };
+}
+
+generate_python_tests!(generate_signature_keypair, None);
+
+// TODO(mulmarta): it'll break if we use async trait which will be
+// supported in the next UniFFI release
+// TODO(mgeisler): add back simple_scenario_async
+generate_python_tests!(simple_scenario_sync, None);