Added ability to validate options values when being set

cmd/micro/settings.go

@@ -12,9 +12,20 @@ import (
 	"github.com/zyedidia/glob"
 )
 
+type optionValidator func(string, interface{}) error
+
 // The options that the user can set
 var globalSettings map[string]interface{}
 
+// Options with validators
+var optionValidators = map[string]optionValidator{
+	"tabsize":      validatePositiveValue,
+	"scrollmargin": validateNonNegativeValue,
+	"scrollspeed":  validateNonNegativeValue,
+	"colorscheme":  validateColorscheme,
+	"colorcolumn":  validateNonNegativeValue,
+}
+
 // InitGlobalSettings initializes the options map and sets all options to their default values
 func InitGlobalSettings() {
 	defaults := DefaultGlobalSettings()
@@ -210,12 +221,6 @@ func DefaultLocalSettings() map[string]interface{} {
 // is local only it will set the local version
 // Use setlocal to force an option to be set locally
 func SetOption(option, value string) error {
-	if option == "colorscheme" {
-		if !ColorschemeExists(value) {
-			return errors.New(value + " is not a valid colorscheme")
-		}
-	}
-
 	if _, ok := globalSettings[option]; !ok {
 		if _, ok := CurView().Buf.Settings[option]; !ok {
 			return errors.New("Invalid option")
@@ -224,23 +229,33 @@ func SetOption(option, value string) error {
 		return nil
 	}
 
+	var nativeValue interface{}
+
 	kind := reflect.TypeOf(globalSettings[option]).Kind()
 	if kind == reflect.Bool {
 		b, err := ParseBool(value)
 		if err != nil {
 			return errors.New("Invalid value")
 		}
-		globalSettings[option] = b
+		nativeValue = b
 	} else if kind == reflect.String {
-		globalSettings[option] = value
+		nativeValue = value
 	} else if kind == reflect.Float64 {
 		i, err := strconv.Atoi(value)
 		if err != nil {
 			return errors.New("Invalid value")
 		}
-		globalSettings[option] = float64(i)
+		nativeValue = float64(i)
+	} else {
+		return errors.New("Option has unsupported value type")
 	}
 
+	if err := optionIsValid(option, nativeValue); err != nil {
+		return err
+	}
+
+	globalSettings[option] = nativeValue
+
 	if option == "colorscheme" {
 		LoadSyntaxFiles()
 		for _, tab := range tabs {
@@ -277,23 +292,33 @@ func SetLocalOption(option, value string, view *View) error {
 		return errors.New("Invalid option")
 	}
 
+	var nativeValue interface{}
+
 	kind := reflect.TypeOf(buf.Settings[option]).Kind()
 	if kind == reflect.Bool {
 		b, err := ParseBool(value)
 		if err != nil {
 			return errors.New("Invalid value")
 		}
-		buf.Settings[option] = b
+		nativeValue = b
 	} else if kind == reflect.String {
-		buf.Settings[option] = value
+		nativeValue = value
 	} else if kind == reflect.Float64 {
 		i, err := strconv.Atoi(value)
 		if err != nil {
 			return errors.New("Invalid value")
 		}
-		buf.Settings[option] = float64(i)
+		nativeValue = float64(i)
+	} else {
+		return errors.New("Option has unsupported value type")
 	}
 
+	if err := optionIsValid(option, nativeValue); err != nil {
+		return err
+	}
+
+	buf.Settings[option] = nativeValue
+
 	if option == "statusline" {
 		view.ToggleStatusLine()
 		if buf.Settings["syntax"].(bool) {
@@ -329,3 +354,55 @@ func SetOptionAndSettings(option, value string) {
 		return
 	}
 }
+
+func optionIsValid(option string, value interface{}) error {
+	if validator, ok := optionValidators[option]; ok {
+		return validator(option, value)
+	}
+
+	return nil
+}
+
+// Option validators
+
+func validatePositiveValue(option string, value interface{}) error {
+	tabsize, ok := value.(float64)
+
+	if !ok {
+		return errors.New("Expected numeric type for " + option)
+	}
+
+	if tabsize < 1 {
+		return errors.New(option + " must be greater than 0")
+	}
+
+	return nil
+}
+
+func validateNonNegativeValue(option string, value interface{}) error {
+	nativeValue, ok := value.(float64)
+
+	if !ok {
+		return errors.New("Expected numeric type for " + option)
+	}
+
+	if nativeValue < 0 {
+		return errors.New(option + " must be non-negative")
+	}
+
+	return nil
+}
+
+func validateColorscheme(option string, value interface{}) error {
+	colorscheme, ok := value.(string)
+
+	if !ok {
+		return errors.New("Expected string type for colorscheme")
+	}
+
+	if !ColorschemeExists(colorscheme) {
+		return errors.New(colorscheme + " is not a valid colorscheme")
+	}
+
+	return nil
+}