more composition tests

README.md

@@ -15,3 +15,7 @@ export LLVM_PROFILE_FILE="prof/%p-%m.profraw"
 ```sh
 ./coverage.sh
 ```
+
+```sh
+clear && npx http-server -p 1337 ./target/debug/coverage
+```

src/func/instances/composition.rs

@@ -181,7 +181,9 @@ impl<'a, U: SharedFunctor<'a> + Functor<'a>, V: SharedFunctor<'a>> SharedFunctor
 mod composition_tests {
     use std::sync::Arc;
 
-    use crate::func::instances::{option::*, result::*, tryfuture::TryFutureInstance};
+    use crate::func::instances::{
+        option::*, result::*, solo::SoloInstance, tryfuture::TryFutureInstance,
+    };
 
     use super::*;
 
@@ -261,4 +263,27 @@ mod composition_tests {
         .unwrap();
         assert!(matches!(res, Selected::B(_, 2)));
     }
+
+    #[test]
+    fn solo_composable() {
+        test_suite::monad_follows_laws::<CompositionInstance<SoloInstance, SoloInstance>>()
+            .unwrap();
+    }
+
+    #[test]
+    fn composition_composable() {
+        test_suite::monad_follows_laws::<
+            CompositionInstance<
+                CompositionInstance<SoloInstance, SoloInstance>,
+                CompositionInstance<SoloInstance, SoloInstance>,
+            >,
+        >()
+        .unwrap();
+    }
+
+    #[test]
+    fn option_composable() {
+        test_suite::monad_follows_laws::<CompositionInstance<OptionInstance, OptionInstance>>()
+            .unwrap();
+    }
 }