refactor: prepare cargo clippy fixes with Rust 2024 by addressing warning "returning the result of a let binding from a block"

Author: dlachaume

internal/cardano-node/mithril-cardano-node-chain/src/entities/datum.rs

@@ -178,7 +178,8 @@ mod test {
 
     fn dummy_tx_datum() -> TxDatum {
         let mut tx_datum_builder = TxDatumBuilder::new();
-        let tx_datum = tx_datum_builder
+
+        tx_datum_builder
             .add_field(TxDatumFieldValue::Bytes("bytes0".to_string()))
             .add_field(TxDatumFieldValue::Int(0))
             .add_field(TxDatumFieldValue::Int(1))
@@ -187,8 +188,7 @@ mod test {
             .add_field(TxDatumFieldValue::Int(2))
             .add_field(TxDatumFieldValue::Bytes("012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789".to_string()))
             .build()
-            .expect("tx_datum build should not fail");
-        tx_datum
+            .expect("tx_datum build should not fail")
     }
 
     #[test]

internal/mithril-doc-derive/src/doc.rs

@@ -36,15 +36,13 @@ pub fn extract_doc_comment(attrs: &[syn::Attribute]) -> Vec<String> {
         })
         .skip_while(|s| is_blank(s))
         .flat_map(|s| {
-            let lines = s
-                .split('\n')
+            s.split('\n')
                 .map(|s| {
                     // remove one leading space no matter what
                     let s = s.strip_prefix(' ').unwrap_or(s);
                     s.to_owned()
                 })
-                .collect::<Vec<_>>();
-            lines
+                .collect::<Vec<_>>()
         })
         .collect();
 

internal/mithril-doc-derive/src/lib.rs

@@ -125,14 +125,12 @@ fn format_field(field: &syn::Field) -> FieldInfo {
         _ => true,
     };
 
-    let field_info = FieldInfo {
+    FieldInfo {
         name: field.ident.as_ref().unwrap().to_string(),
         doc,
         example,
         is_mandatory,
-    };
-
-    field_info
+    }
 }
 
 /// To extract doc from a struct.

internal/mithril-persistence/src/database/version_checker.rs

@@ -303,16 +303,15 @@ mod tests {
 
     fn get_table_whatever_column_count(connection: &SqliteConnection) -> i64 {
         let sql = "select count(*) as column_count from pragma_table_info('whatever');";
-        let column_count = connection
+
+        connection
             .prepare(sql)
             .unwrap()
             .iter()
             .next()
             .unwrap()
             .unwrap()
-            .read::<i64, _>(0);
-
-        column_count
+            .read::<i64, _>(0)
     }
 
     fn create_db_checker(connection: &ConnectionThreadSafe) -> DatabaseVersionChecker {

mithril-client-cli/src/commands/cardano_stake_distribution/download.rs

@@ -161,7 +161,7 @@ impl CardanoStakeDistributionDownloadCommand {
         client: &Client,
         unique_identifier: &str,
     ) -> MithrilResult<CardanoStakeDistribution> {
-        let cardano_stake_distribution = if Self::is_sha256_hash(unique_identifier) {
+        if Self::is_sha256_hash(unique_identifier) {
             client
                 .cardano_stake_distribution()
                 .get(unique_identifier)
@@ -212,9 +212,7 @@ impl CardanoStakeDistributionDownloadCommand {
                     "No Cardano stake distribution could be found for epoch: '{}'",
                     epoch
                 ))
-        };
-
-        cardano_stake_distribution
+        }
     }
 }
 

mithril-common/src/certificate_chain/certificate_verifier.rs

@@ -1104,9 +1104,8 @@ mod tests {
                         .to_owned()
                         .try_new_with_protocol_parameters(forged_protocol_parameters.clone())
                         .unwrap();
-                    let signature = s_adversary.protocol_signer.sign(signed_message.as_bytes());
 
-                    signature
+                    s_adversary.protocol_signer.sign(signed_message.as_bytes())
                 })
                 .collect::<Vec<_>>();
             let forged_clerk = ProtocolClerk::from_registration(