runtime-sdk: Better support tests setting the chain context

runtime-sdk/modules/evm/src/test.rs

@@ -281,12 +281,14 @@ fn test_evm_calls() {
 
 #[test]
 fn test_c10l_evm_calls() {
+    let _guard = crypto::signature::context::test_using_chain_context();
     crypto::signature::context::set_chain_context(Default::default(), "test");
     do_test_evm_calls::<ConfidentialEVMConfig>();
 }
 
 #[test]
 fn test_c10l_evm_balance_transfer() {
+    let _guard = crypto::signature::context::test_using_chain_context();
     crypto::signature::context::set_chain_context(Default::default(), "test");
     let mut mock = mock::Mock::default();
     let mut ctx = mock.create_ctx();
@@ -771,6 +773,7 @@ fn test_evm_runtime() {
 
 #[test]
 fn test_c10l_evm_runtime() {
+    let _guard = crypto::signature::context::test_using_chain_context();
     crypto::signature::context::set_chain_context(Default::default(), "test");
     do_test_evm_runtime::<ConfidentialEVMConfig>();
 }

runtime-sdk/src/crypto/signature/context.rs

@@ -69,20 +69,32 @@ pub fn set_chain_context(runtime_id: Namespace, consensus_chain_context: &str) {
     *guard = Some(ctx.into_bytes());
 }
 
+/// Test helper to serialize unit tests using the global chain context. The chain context is reset
+/// when this method is called.
+///
+/// # Example
+///
+/// ```rust
+/// # use oasis_runtime_sdk::crypto::signature::context::test_using_chain_context;
+/// let _guard = test_using_chain_context();
+/// // ... rest of the test code follows ...
+/// ```
+#[cfg(any(test, feature = "test"))]
+pub fn test_using_chain_context() -> std::sync::MutexGuard<'static, ()> {
+    static TEST_USING_CHAIN_CONTEXT: Lazy<Mutex<()>> = Lazy::new(Default::default);
+    let guard = TEST_USING_CHAIN_CONTEXT.lock().unwrap();
+    *CHAIN_CONTEXT.lock().unwrap() = None;
+
+    guard
+}
+
 #[cfg(test)]
 mod test {
     use super::*;
 
-    static TEST_GUARD: Lazy<Mutex<()>> = Lazy::new(Default::default);
-
-    fn reset_chain_context() {
-        *CHAIN_CONTEXT.lock().unwrap() = None;
-    }
-
     #[test]
     fn test_chain_context() {
-        let _guard = TEST_GUARD.lock().unwrap();
-        reset_chain_context();
+        let _guard = test_using_chain_context();
         set_chain_context(
             "8000000000000000000000000000000000000000000000000000000000000000".into(),
             "643fb06848be7e970af3b5b2d772eb8cfb30499c8162bc18ac03df2f5e22520e",
@@ -94,17 +106,15 @@ mod test {
 
     #[test]
     fn test_chain_context_not_configured() {
-        let _guard = TEST_GUARD.lock().unwrap();
-        reset_chain_context();
+        let _guard = test_using_chain_context();
 
         let result = std::panic::catch_unwind(|| get_chain_context_for(b"test"));
         assert!(result.is_err());
     }
 
     #[test]
     fn test_chain_context_already_configured() {
-        let _guard = TEST_GUARD.lock().unwrap();
-        reset_chain_context();
+        let _guard = test_using_chain_context();
         set_chain_context(
             "8000000000000000000000000000000000000000000000000000000000000000".into(),
             "643fb06848be7e970af3b5b2d772eb8cfb30499c8162bc18ac03df2f5e22520e",