Make light client backend only work with locally available data (#3538)

* removing fetcher dependency from light backend

* fix compilation

substrate/core/test-runtime/client/src/lib.rs

@@ -73,20 +73,11 @@ pub type Executor = client::LocalCallExecutor<
 pub type LightBackend = generic_test_client::LightBackend<runtime::Block>;
 
 /// Test client light executor.
-pub type LightExecutor = client::light::call_executor::RemoteOrLocalCallExecutor<
-	runtime::Block,
+pub type LightExecutor = client::light::call_executor::GenesisCallExecutor<
 	LightBackend,
-	client::light::call_executor::RemoteCallExecutor<
-		client::light::blockchain::Blockchain<
-			client_db::light::LightStorage<runtime::Block>,
-			LightFetcher
-		>,
-		LightFetcher
-	>,
 	client::LocalCallExecutor<
 		client::light::backend::Backend<
 			client_db::light::LightStorage<runtime::Block>,
-			LightFetcher,
 			Blake2Hasher
 		>,
 		NativeExecutor<LocalExecutor>
@@ -271,22 +262,16 @@ pub fn new_light() -> (
 	let blockchain = Arc::new(client::light::blockchain::Blockchain::new(storage));
 	let backend = Arc::new(LightBackend::new(blockchain.clone()));
 	let executor = NativeExecutor::new(None);
-	let fetcher = Arc::new(LightFetcher);
-	let remote_call_executor = client::light::call_executor::RemoteCallExecutor::new(
-		blockchain.clone(),
-		fetcher,
-	);
 	let local_call_executor = client::LocalCallExecutor::new(backend.clone(), executor, None);
 	let call_executor = LightExecutor::new(
 		backend.clone(),
-		remote_call_executor,
 		local_call_executor,
 	);
 
-	(TestClientBuilder::with_backend(backend.clone())
-		.build_with_executor(call_executor)
-		.0,
-	backend,
+	(
+		TestClientBuilder::with_backend(backend.clone())
+			.build_with_executor(call_executor)
+			.0,
+		backend,
 	)
-
 }