Updates chain field of getmininginfo response

zebra-rpc/src/methods/get_block_template_rpcs/types/get_mining_info.rs

@@ -2,6 +2,26 @@
 
 use zebra_chain::parameters::Network;
 
+/// `chain` field of [`Response`] as defined in BIP70
+#[derive(Debug, PartialEq, Eq, serde::Serialize)]
+#[serde(rename_all = "lowercase")]
+pub enum ChainNetworkResponse {
+    /// Corresponds to Mainnet
+    Main,
+
+    /// Corresponds to Testnet
+    Test,
+}
+
+impl From<Network> for ChainNetworkResponse {
+    fn from(network: Network) -> Self {
+        match network {
+            Network::Mainnet => Self::Main,
+            Network::Testnet => Self::Test,
+        }
+    }
+}
+
 /// Response to a `getmininginfo` RPC request.
 #[derive(Debug, PartialEq, Eq, serde::Serialize)]
 pub struct Response {
@@ -12,20 +32,20 @@ pub struct Response {
     networkhashps: u128,
 
     /// Current network name as defined in BIP70 (main, test, regtest)
-    chain: Network,
+    chain: ChainNetworkResponse,
 
     /// If using testnet or not
     testnet: bool,
 }
 
 impl Response {
     /// Creates a new `getmininginfo` response
-    pub fn new(chain: Network, networksolps: u128) -> Self {
+    pub fn new(network: Network, networksolps: u128) -> Self {
         Self {
             networksolps,
             networkhashps: networksolps,
-            chain,
-            testnet: chain == Network::Testnet,
+            chain: network.into(),
+            testnet: network == Network::Testnet,
         }
     }
 }