(#62) Correctly validate all flags and args

app.go

@@ -622,42 +622,24 @@ func (a *Application) execute(context *ParseContext, selected []string) (string,
 }
 
 func (a *Application) validateFlagsAndArgs(context *ParseContext) error {
-	flagElements := map[string]*ParseElement{}
 	for _, element := range context.Elements {
 		if flag, ok := element.Clause.(*FlagClause); ok {
-			if flag.validator == nil {
-				return nil
+			if flag.validator != nil {
+				err := flag.validator(*element.Value)
+				if err != nil {
+					return fmt.Errorf("%s: %w", flag.name, err)
+				}
 			}
-			flagElements[flag.name] = element
 		}
 	}
 
-	argElements := map[string]*ParseElement{}
 	for _, element := range context.Elements {
 		if arg, ok := element.Clause.(*ArgClause); ok {
-			if arg.validator == nil {
-				return nil
-			}
-			argElements[arg.name] = element
-		}
-	}
-
-	for _, flag := range flagElements {
-		clause := flag.Clause.(*FlagClause)
-		if clause.validator != nil {
-			err := clause.validator(*flag.Value)
-			if err != nil {
-				return fmt.Errorf("%s: %w", clause.name, err)
-			}
-		}
-	}
-
-	for _, arg := range argElements {
-		clause := arg.Clause.(*ArgClause)
-		if clause.validator != nil {
-			err := clause.validator(*arg.Value)
-			if err != nil {
-				return fmt.Errorf("%s: %w", clause.name, err)
+			if arg.validator != nil {
+				err := arg.validator(*element.Value)
+				if err != nil {
+					return fmt.Errorf("%s: %w", arg.name, err)
+				}
 			}
 		}
 	}
@@ -784,7 +766,6 @@ func (a *Application) setValues(context *ParseContext) (selected []string, err e
 }
 
 func (a *Application) applyValidators(context *ParseContext) (err error) {
-	// Call command validation functions.
 	for _, element := range context.Elements {
 		if cmd, ok := element.Clause.(*CmdClause); ok && cmd.validator != nil {
 			if err = cmd.validator(cmd); err != nil {
@@ -795,8 +776,12 @@ func (a *Application) applyValidators(context *ParseContext) (err error) {
 
 	if a.validator != nil {
 		err = a.validator(a)
+		if err != nil {
+			return err
+		}
 	}
-	return err
+
+	return nil
 }
 
 func (a *Application) applyPreActions(context *ParseContext, dispatch bool) error {

flags_test.go

@@ -411,7 +411,9 @@ func TestValidator(t *testing.T) {
 
 	app := newTestApp()
 
+	app.Arg("first", "First arg").String()
 	arg := app.Arg("arg", "A arg").Default("a").Validator(regexpValidator("^[abc]$")).String()
+	app.Flag("first", "First arg").String()
 	flag := app.Flag("flag", "A flag").Validator(regexpValidator("^[xyz]$")).String()
 
 	_, err := app.Parse([]string{"--flag", "x"})
@@ -421,14 +423,14 @@ func TestValidator(t *testing.T) {
 
 	*arg = ""
 	*flag = ""
-	_, err = app.Parse([]string{"b", "--flag", "x"})
+	_, err = app.Parse([]string{"1st", "b", "--flag", "x"})
 	assert.NoError(t, err)
 	assert.Equal(t, *flag, "x")
 	assert.Equal(t, *arg, "b")
 
 	*arg = ""
 	*flag = ""
-	_, err = app.Parse([]string{"z", "--flag", "x"})
+	_, err = app.Parse([]string{"1st", "z", "--flag", "x"})
 	assert.Error(t, err, `does not validate using "^[abc]$"`)
 	assert.Equal(t, *flag, "")
 	assert.Equal(t, *arg, "")

go.mod

@@ -4,7 +4,7 @@ go 1.23.0
 
 require (
 	github.com/stretchr/testify v1.10.0
-	golang.org/x/text v0.24.0
+	golang.org/x/text v0.28.0
 )
 
 require (

go.sum

@@ -4,8 +4,8 @@ github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZb
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
 github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
-golang.org/x/text v0.24.0 h1:dd5Bzh4yt5KYA8f9CJHCP4FB4D51c2c6JvN37xJJkJ0=
-golang.org/x/text v0.24.0/go.mod h1:L8rBsPeo2pSS+xqN0d5u2ikmjtmoJbDBT1b7nHvFCdU=
+golang.org/x/text v0.28.0 h1:rhazDwis8INMIwQ4tpjLDzUhx6RlXqZNPEM0huQojng=
+golang.org/x/text v0.28.0/go.mod h1:U8nCwOR8jO/marOQ0QbDiOngZVEBB7MAiitBuMjXiNU=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=