Wasm storage read test (#6255)

* Test for read from prepopulated storage implemented

* wasm-tests submodule update

* fix identation

* comment for storage_read added

ethcore/res/wasm-tests

@@ -1 +1 @@
-Subproject commit 04c9d84c5fe5c3ad707be58664c7e72b97cc9996
+Subproject commit 18dad7912cf42937ff725ffd944d01ff7ca1cce7

ethcore/wasm/src/tests.rs

@@ -388,3 +388,29 @@ fn realloc() {
 	assert_eq!(gas_left, U256::from(98326));
 	assert_eq!(result, vec![0u8; 2]);
 }
+
+// Tests that contract's ability to read from a storage
+// Test prepopulates address into storage, than executes a contract which read that address from storage and write this address into result
+#[test]
+fn storage_read() {
+	let code = load_sample!("storage_read.wasm");
+	let address: Address = "0f572e5295c57f15886f9b263e2f6d2d6c7b5ec6".parse().unwrap();
+	
+	let mut params = ActionParams::default();
+	params.gas = U256::from(100_000);
+	params.code = Some(Arc::new(code));
+	let mut ext = FakeExt::new();
+	ext.store.insert("0100000000000000000000000000000000000000000000000000000000000000".into(), address.into());
+
+	let (gas_left, result) = {
+		let mut interpreter = wasm_interpreter();
+		let result = interpreter.exec(params, &mut ext).expect("Interpreter to execute without any errors");
+		match result {
+				GasLeft::Known(_) => { panic!("storage_read should return payload"); },
+				GasLeft::NeedsReturn { gas_left: gas, data: result, apply_state: _apply } => (gas, result.to_vec()),
+		}
+	};
+
+	assert_eq!(gas_left, U256::from(99752));
+	assert_eq!(Address::from(&result[12..32]), address);
+}