fix: avoid panic with plugin without description (#5312)

Author: ldez

Diff for: pkg/commands/help.go

@@ -210,6 +210,12 @@ func printLinters(lcs []*linter.Config) {
 }
 
 func formatDescription(desc string) string {
+	desc = strings.TrimSpace(desc)
+
+	if desc == "" {
+		return desc
+	}
+
 	// If the linter description spans multiple lines, truncate everything following the first newline
 	endFirstLine := strings.IndexRune(desc, '\n')
 	if endFirstLine > 0 {

Diff for: pkg/commands/help_test.go

@@ -0,0 +1,51 @@
+package commands
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_formatDescription(t *testing.T) {
+	testCases := []struct {
+		desc     string
+		doc      string
+		expected string
+	}{
+		{
+			desc:     "empty description",
+			doc:      "",
+			expected: "",
+		},
+		{
+			desc:     "simple description",
+			doc:      "this is a test",
+			expected: "This is a test.",
+		},
+		{
+			desc:     "formatted description",
+			doc:      "This is a test.",
+			expected: "This is a test.",
+		},
+		{
+			desc:     "multiline description",
+			doc:      "this is a test\nanother line\n",
+			expected: "This is a test.",
+		},
+		{
+			desc:     "leading newline",
+			doc:      "\nThis is a test.",
+			expected: "This is a test.",
+		},
+	}
+
+	for _, test := range testCases {
+		t.Run(test.desc, func(t *testing.T) {
+			t.Parallel()
+
+			v := formatDescription(test.doc)
+
+			assert.Equal(t, test.expected, v)
+		})
+	}
+}