refactor: add WithNameEx() func to wrap arbitrary regex rule

pkg/config/with.go

@@ -0,0 +1,12 @@
+package config
+
+import (
+	"github.com/ivanilves/travelgrunt/pkg/config/rule"
+)
+
+// WithNameEx returns a copy of config with regex-based rule added
+func (cfg Config) WithNameEx(nameEx string) Config {
+	cfg.Rules = append(cfg.Rules, rule.Rule{NameEx: nameEx})
+
+	return cfg
+}

pkg/config/with_test.go

@@ -0,0 +1,19 @@
+package config
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestWithNameEx(t *testing.T) {
+	assert := assert.New(t)
+
+	cfg := DefaultConfig()
+
+	n := len(cfg.Rules)
+
+	cfg = cfg.WithNameEx("*.tf")
+
+	assert.Len(cfg.Rules, n+1)
+}