op-node: Properly return error on bad hex data (#3365)

* op-node: Properly return error on bad hex data

* Add forgotten err to Pub2PeerID
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

op-node/cmd/p2p/cmd.go

@@ -16,7 +16,7 @@ import (
 func Priv2PeerID(r io.Reader) (string, error) {
 	b, err := readHexData(r)
 	if err != nil {
-		return "", nil
+		return "", err
 	}
 
 	p, err := crypto.UnmarshalSecp256k1PrivateKey(b)
@@ -34,7 +34,7 @@ func Priv2PeerID(r io.Reader) (string, error) {
 func Pub2PeerID(r io.Reader) (string, error) {
 	b, err := readHexData(r)
 	if err != nil {
-		return "", nil
+		return "", err
 	}
 
 	p, err := crypto.UnmarshalSecp256k1PublicKey(b)

op-node/cmd/p2p/cmd_test.go

@@ -32,4 +32,8 @@ func TestPrivPub2PeerID(t *testing.T) {
 		require.NoError(t, err)
 		require.Equal(t, pubPidLib.String(), pubPidImpl)
 	})
+	t.Run("with bad hex", func(t *testing.T) {
+		_, err := Priv2PeerID(bytes.NewReader([]byte("I am not hex.")))
+		require.Error(t, err)
+	})
 }