From e8c475c6cbbc6056987ff026cf2ce22f471b6220 Mon Sep 17 00:00:00 2001
From: Daniel Savu <savudani04@yahoo.ro>
Date: Mon, 9 May 2022 20:49:54 +0100
Subject: [PATCH 1/2] feat: fail to start on metadata mismatch

---
 runtime/src/error.rs |  2 ++
 runtime/src/rpc.rs   | 17 +++++++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/runtime/src/error.rs b/runtime/src/error.rs
index a0a1df50c..04d89c31b 100644
--- a/runtime/src/error.rs
+++ b/runtime/src/error.rs
@@ -55,6 +55,8 @@ pub enum Error {
     InsufficientFunds,
     #[error("Client does not support spec_version: expected {0}, got {1}")]
     InvalidSpecVersion(u32, u32),
+    #[error("Client metadata is different from parachain metadata: expected {0}, got {1}")]
+    ParachainMetadataMismatch(String, String),
     #[error("Failed to load credentials from file: {0}")]
     KeyLoadingFailure(#[from] KeyLoadingError),
     #[error("Error serializing: {0}")]
diff --git a/runtime/src/rpc.rs b/runtime/src/rpc.rs
index 1641c398f..a9e143678 100644
--- a/runtime/src/rpc.rs
+++ b/runtime/src/rpc.rs
@@ -13,6 +13,7 @@ use codec::Encode;
 use futures::{future::join_all, stream::StreamExt, FutureExt, SinkExt};
 use module_oracle_rpc_runtime_api::BalanceWrapper;
 use primitives::UnsignedFixedPoint;
+use serde_json::{Map, Value};
 use sp_runtime::FixedPointNumber;
 use std::{collections::BTreeSet, future::Future, sync::Arc, time::Duration};
 use subxt::{
@@ -30,15 +31,19 @@ const TRANSACTION_TIMEOUT: Duration = Duration::from_secs(300); // 5 minute time
 cfg_if::cfg_if! {
     if #[cfg(feature = "standalone-metadata")] {
         const DEFAULT_SPEC_VERSION: u32 = 1;
+        const DEFAULT_SPEC_NAME: &str = "interbtc-standalone";
         pub const SS58_PREFIX: u16 = 42;
     } else if #[cfg(feature = "parachain-metadata-interlay")] {
         const DEFAULT_SPEC_VERSION: u32 = 3;
+        const DEFAULT_SPEC_NAME: &str = "interlay-parachain";
         pub const SS58_PREFIX: u16 = 2032;
     } else if #[cfg(feature = "parachain-metadata-kintsugi")] {
         const DEFAULT_SPEC_VERSION: u32 = 15;
+        const DEFAULT_SPEC_NAME: &str = "kintsugi-parachain";
         pub const SS58_PREFIX: u16 = 2092;
     } else if #[cfg(feature = "parachain-metadata-testnet")] {
         const DEFAULT_SPEC_VERSION: u32 = 6;
+        const DEFAULT_SPEC_NAME: &str = "testnet-parachain";
         pub const SS58_PREFIX: u16 = 42;
     }
 }
@@ -69,6 +74,18 @@ impl InterBtcParachain {
         let api: RuntimeApi = ext_client.clone().to_runtime_api();
 
         let runtime_version = ext_client.rpc().runtime_version(None).await?;
+        if let Some(spec_name) = runtime_version.other.get("specName") {
+            if spec_name == DEFAULT_SPEC_NAME {
+                log::info!("spec_name={}", spec_name);
+            } else {
+                return Err(Error::ParachainMetadataMismatch(
+                    DEFAULT_SPEC_NAME.into(),
+                    // The spec name is always expected to be a string if defined, so `unwrap()` never panics.
+                    spec_name.as_str().unwrap().into(),
+                ));
+            }
+        }
+
         if runtime_version.spec_version == DEFAULT_SPEC_VERSION {
             log::info!("spec_version={}", runtime_version.spec_version);
             log::info!("transaction_version={}", runtime_version.transaction_version);

From 580617464a9daffb4add1a82d90c58efa6883221 Mon Sep 17 00:00:00 2001
From: Daniel Savu <savudani04@yahoo.ro>
Date: Tue, 10 May 2022 14:07:32 +0100
Subject: [PATCH 2/2] chore: unwrap spec_name to default

---
 runtime/src/rpc.rs | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/runtime/src/rpc.rs b/runtime/src/rpc.rs
index a9e143678..4ce2e8440 100644
--- a/runtime/src/rpc.rs
+++ b/runtime/src/rpc.rs
@@ -74,16 +74,15 @@ impl InterBtcParachain {
         let api: RuntimeApi = ext_client.clone().to_runtime_api();
 
         let runtime_version = ext_client.rpc().runtime_version(None).await?;
-        if let Some(spec_name) = runtime_version.other.get("specName") {
-            if spec_name == DEFAULT_SPEC_NAME {
-                log::info!("spec_name={}", spec_name);
-            } else {
-                return Err(Error::ParachainMetadataMismatch(
-                    DEFAULT_SPEC_NAME.into(),
-                    // The spec name is always expected to be a string if defined, so `unwrap()` never panics.
-                    spec_name.as_str().unwrap().into(),
-                ));
-            }
+        let default_spec_name = &Value::default();
+        let spec_name = runtime_version.other.get("specName").unwrap_or(default_spec_name);
+        if spec_name == DEFAULT_SPEC_NAME {
+            log::info!("spec_name={}", spec_name);
+        } else {
+            return Err(Error::ParachainMetadataMismatch(
+                DEFAULT_SPEC_NAME.into(),
+                spec_name.as_str().unwrap_or_default().into(),
+            ));
         }
 
         if runtime_version.spec_version == DEFAULT_SPEC_VERSION {