test: add coverage for mutants

Author: kantai

stacks-signer/src/client/stacks_client.rs

@@ -33,7 +33,7 @@ use blockstack_lib::net::api::get_tenures_fork_info::{
 use blockstack_lib::net::api::getaccount::AccountEntryResponse;
 use blockstack_lib::net::api::getpoxinfo::RPCPoxInfoData;
 use blockstack_lib::net::api::getsortition::{SortitionInfo, RPC_SORTITION_INFO_PATH};
-use blockstack_lib::net::api::getstackers::GetStackersResponse;
+use blockstack_lib::net::api::getstackers::{GetStackersErrors, GetStackersResponse};
 use blockstack_lib::net::api::postblock::StacksBlockAcceptedData;
 use blockstack_lib::net::api::postblock_proposal::NakamotoBlockProposal;
 use blockstack_lib::net::api::postblock_v3;
@@ -541,7 +541,7 @@ impl StacksClient {
                 warn!("Failed to parse the GetStackers error response: {e}");
                 backoff::Error::permanent(e.into())
             })?;
-            if error_data.err_type == "not_available_try_again" {
+            if &error_data.err_type == GetStackersErrors::NOT_AVAILABLE_ERR_TYPE {
                 return Err(backoff::Error::transient(ClientError::NoSortitionOnChain));
             } else {
                 warn!("Got error response ({status}): {}", error_data.err_msg);

stackslib/src/net/api/getstackers.rs

@@ -57,10 +57,13 @@ pub enum GetStackersErrors {
 }
 
 impl GetStackersErrors {
+    pub const NOT_AVAILABLE_ERR_TYPE: &'static str = "not_available_try_again";
+    pub const OTHER_ERR_TYPE: &'static str = "other";
+
     pub fn error_type_string(&self) -> &'static str {
         match self {
-            GetStackersErrors::NotAvailableYet(_) => "not_available_try_again",
-            GetStackersErrors::Other(_) => "other",
+            Self::NotAvailableYet(_) => Self::NOT_AVAILABLE_ERR_TYPE,
+            Self::Other(_) => Self::OTHER_ERR_TYPE,
         }
     }
 }
@@ -252,3 +255,31 @@ impl StacksHttpResponse {
         Ok(response)
     }
 }
+
+#[cfg(test)]
+mod test {
+    use super::GetStackersErrors;
+
+    #[test]
+    // Test the formatting and error type strings of GetStackersErrors
+    fn get_stackers_errors() {
+        let not_available_err = GetStackersErrors::NotAvailableYet(
+            crate::chainstate::coordinator::Error::PoXNotProcessedYet,
+        );
+        let other_err = GetStackersErrors::Other("foo".into());
+
+        assert_eq!(
+            not_available_err.error_type_string(),
+            GetStackersErrors::NOT_AVAILABLE_ERR_TYPE
+        );
+        assert_eq!(
+            other_err.error_type_string(),
+            GetStackersErrors::OTHER_ERR_TYPE
+        );
+
+        assert!(not_available_err
+            .to_string()
+            .starts_with("Could not read reward set"));
+        assert_eq!(other_err.to_string(), "foo".to_string());
+    }
+}

testnet/stacks-node/src/nakamoto_node/sign_coordinator.rs

@@ -631,6 +631,9 @@ impl SignCoordinator {
     /// This function begins by sending a `BlockProposal` message
     /// to the signers, and then waits for the signers to respond
     /// with their signatures.
+    // Mutants skip here: this function is covered via integration tests,
+    //  which the mutation testing does not see.
+    #[cfg_attr(test, mutants::skip)]
     pub fn begin_sign_v0(
         &mut self,
         block: &NakamotoBlock,