added e2e test

lib.rs

@@ -2,7 +2,7 @@
 // and we need to use `no_std` and `no_main` attributes
 // to compile the contract as a Wasm binary.
 // If `std` feature is enabled, we are building for native target
-// and we don't need these attributes. 
+// and we don't need these attributes.
 // ink! builds in `std` mode when running tests.
 //
 // `no_std` attribute disables the standard library.
@@ -183,4 +183,48 @@ mod cross_contract_flipper {
             todo!()
         }
     }
+
+    #[cfg(all(test, feature = "e2e-tests"))]
+    mod e2e_tests {
+        use super::*;
+        use ink_e2e::ContractsBackend;
+
+        type E2EResult<T> = std::result::Result<T, Box<dyn std::error::Error>>;
+
+        #[ink_e2e::test]
+        async fn it_works<Client: ContractsBackend>(mut client: Client) -> E2EResult<()> {
+            let mut constructor = OtherContractRef::new(true);
+            let _contract = client
+                .instantiate("other_contract", &ink_e2e::alice(), &mut constructor)
+                .submit()
+                .await
+                .expect("instantiate failed");
+
+            let code_hash = client
+                .upload("other_contract", &ink_e2e::alice())
+                .submit()
+                .await
+                .expect("upload failed")
+                .code_hash;
+
+            let mut constructor = CrossContractFlipperRef::new(code_hash);
+            let cross_contract = client
+                .instantiate(
+                    "cross_contract_flipper",
+                    &ink_e2e::alice(),
+                    &mut constructor,
+                )
+                .submit()
+                .await
+                .expect("instantiate failed");
+
+            let mut call_builder = cross_contract.call_builder::<CrossContractFlipper>();
+
+            let get = call_builder.call_get();
+            let get_res = client.call(&ink_e2e::bob(), &get).dry_run().await?;
+            assert!(matches!(get_res.return_value(), true));
+
+            Ok(())
+        }
+    }
 }