feat(config): add support for string slice flags in traverseStruct (#80)

* feat(config): add support for string slice flags in traverseStruct

* chore: fix test

Author: aaronschweig

config/config.go

@@ -166,6 +166,11 @@ func traverseStruct(value reflect.Value, flagSet *pflag.FlagSet, prefix string)
 				defaultBoolValue = b
 			}
 			flagSet.Bool(prefix+tag, defaultBoolValue, description)
+		case reflect.Slice:
+			if fieldValue.Type().Elem().Kind() != reflect.String {
+				return fmt.Errorf("unsupported slice element type %s for field %s", fieldValue.Type().Elem().Kind(), field.Name)
+			}
+			flagSet.StringSlice(prefix+tag, []string{}, description)
 		default:
 			return fmt.Errorf("unsupported field type %s for field %s", fieldValue.Kind(), field.Name)
 		}

config/config_test.go

@@ -36,6 +36,7 @@ func TestBindConfigToFlags(t *testing.T) {
 		CustomFlagStruct2 struct {
 			CustomFlagDuration time.Duration `mapstructure:"custom-flag-duration-2"`
 		} `mapstructure:"le-strFlag"`
+		Slice []string `mapstructure:"slice" description:"This is a slice of strings"`
 	}
 
 	testStruct := test{}
@@ -171,7 +172,7 @@ func TestNewDefaultConfig(t *testing.T) {
 
 func TestGenerateFlagSetUnsupportedType(t *testing.T) {
 	type test struct {
-		UnsupportedField []string `mapstructure:"unsupported-field"`
+		UnsupportedField []int `mapstructure:"unsupported-field"`
 	}
 	testStruct := test{}
 	err := config.BindConfigToFlags(viper.New(), &cobra.Command{}, &testStruct)