core/: Add display implementation for DialError<THandler>

core/src/network.rs

@@ -569,7 +569,7 @@ impl NetworkConfig {
 }
 
 /// Possible (synchronous) errors when dialing a peer.
-#[derive(Debug, Clone, Error)]
+#[derive(Clone, Error)]
 pub enum DialError<THandler> {
     /// The dialing attempt is rejected because of a connection limit.
     ConnectionLimit {
@@ -578,12 +578,56 @@ pub enum DialError<THandler> {
     },
     /// The dialing attempt is rejected because the peer being dialed is the local peer.
     LocalPeerId { handler: THandler },
+    /// The dialing attempt is rejected because the PeerId is invalid.
     InvalidPeerId {
         handler: THandler,
         multihash: Multihash,
     },
 }
 
+impl<THandler> fmt::Debug for DialError<THandler> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            DialError::ConnectionLimit { limit, handler: _ } => f
+                .debug_struct("DialError::ConnectionLimit")
+                .field("limit", limit)
+                .finish(),
+            DialError::LocalPeerId { handler: _ } => {
+                f.debug_struct("DialError::LocalPeerId").finish()
+            }
+            DialError::InvalidPeerId {
+                handler: _,
+                multihash,
+            } => f
+                .debug_struct("DialError::InvalidPeerId")
+                .field("multihash", multihash)
+                .finish(),
+        }
+    }
+}
+
+impl<THandler> fmt::Display for DialError<THandler> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            DialError::ConnectionLimit { limit, handler: _ } => {
+                write!(
+                    f,
+                    "The dialing attempt was rejected because of a connection limit: {limit}"
+                )
+            }
+            DialError::LocalPeerId { .. } => {
+                write!(f, "The dialing attempt was rejected because the peer being dialed is the local peer.")
+            }
+            DialError::InvalidPeerId {
+                multihash,
+                handler: _,
+            } => {
+                write!(f, "The dialing attempt was rejected because a valid PeerId could not be constructed from: {:?}", multihash)
+            }
+        }
+    }
+}
+
 /// Options to configure a dial to a known or unknown peer.
 ///
 /// Used in [`Network::dial`].