fetch system chain, name and version (paritytech#385)

* fetch system chain, name and version

* add fetch system tests

* fix fetch system test

* fix cargo fmt

* fix cargo clippy

src/rpc.rs

@@ -391,6 +391,21 @@ impl<T: Config> Rpc<T> {
         Ok(self.client.request("system_properties", &[]).await?)
     }
 
+    /// Fetch system chain
+    pub async fn system_chain(&self) -> Result<String, Error> {
+        Ok(self.client.request("system_chain", &[]).await?)
+    }
+
+    /// Fetch system name
+    pub async fn system_name(&self) -> Result<String, Error> {
+        Ok(self.client.request("system_name", &[]).await?)
+    }
+
+    /// Fetch system version
+    pub async fn system_version(&self) -> Result<String, Error> {
+        Ok(self.client.request("system_version", &[]).await?)
+    }
+
     /// Get a header
     pub async fn header(
         &self,

tests/integration/client.rs

@@ -122,3 +122,12 @@ async fn test_iter() {
     }
     assert_eq!(i, 13);
 }
+
+#[async_std::test]
+async fn fetch_system_info() {
+    let node_process = test_node_process().await;
+    let client = node_process.client();
+    assert_eq!(client.rpc().system_chain().await.unwrap(), "Development");
+    assert_eq!(client.rpc().system_name().await.unwrap(), "Substrate Node");
+    assert!(!client.rpc().system_version().await.unwrap().is_empty());
+}