refactor: modify enr error message

cmd/enr.go

@@ -18,10 +18,12 @@ package cmd
 import (
 	"fmt"
 	"io"
+	"io/fs"
 
 	"github.com/spf13/cobra"
 
 	"github.com/obolnetwork/charon/app/errors"
+	"github.com/obolnetwork/charon/app/z"
 	"github.com/obolnetwork/charon/p2p"
 )
 
@@ -50,7 +52,9 @@ func newEnrCmd(runFunc func(io.Writer, p2p.Config, string) error) *cobra.Command
 // runNewENR loads the p2pkey from disk and prints the ENR for the provided config.
 func runNewENR(w io.Writer, config p2p.Config, dataDir string) error {
 	key, err := p2p.LoadPrivKey(dataDir)
-	if err != nil {
+	if errors.Is(err, fs.ErrNotExist) {
+		return errors.New("ENR private key not found. If this is your first time running this client, create one with `charon create enr`.", z.Str("enr_path", p2p.KeyPath(dataDir))) //nolint:revive
+	} else if err != nil {
 		return err
 	}
 

cmd/enr_internal_test.go

@@ -0,0 +1,37 @@
+// Copyright © 2022 Obol Labs Inc.
+//
+// This program is free software: you can redistribute it and/or modify it
+// under the terms of the GNU General Public License as published by the Free
+// Software Foundation, either version 3 of the License, or (at your option)
+// any later version.
+//
+// This program is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of  MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+// more details.
+//
+// You should have received a copy of the GNU General Public License along with
+// this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package cmd
+
+import (
+	"io"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/obolnetwork/charon/app/errors"
+	"github.com/obolnetwork/charon/app/z"
+	"github.com/obolnetwork/charon/p2p"
+)
+
+func TestRunNewEnr(t *testing.T) {
+	temp, err := os.MkdirTemp("", "")
+	require.NoError(t, err)
+
+	got := runNewENR(io.Discard, p2p.Config{}, temp)
+	expected := errors.New("ENR private key not found. If this is your first time running this client, create one with `charon create enr`.", z.Str("enr_path", p2p.KeyPath(temp)))
+	require.Equal(t, expected.Error(), got.Error())
+}

p2p/k1.go

@@ -34,7 +34,7 @@ func KeyPath(datadir string) string {
 func LoadPrivKey(dataDir string) (*ecdsa.PrivateKey, error) {
 	key, err := crypto.LoadECDSA(KeyPath(dataDir))
 	if err != nil {
-		return nil, errors.Wrap(err, "load key")
+		return nil, errors.Wrap(err, "load priv key")
 	}
 
 	return key, nil