Flag ignores default value

argparse.go

@@ -191,12 +191,13 @@ func (o *Command) Flag(short string, long string, opts *Options) *bool {
 	var result bool
 
 	a := &arg{
-		result: &result,
-		sname:  short,
-		lname:  long,
-		size:   1,
-		opts:   opts,
-		unique: true,
+		result:  &result,
+		sname:   short,
+		lname:   long,
+		size:    1,
+		opts:    opts,
+		unique:  true,
+		argType: Flag,
 	}
 
 	if err := o.addArg(a); err != nil {
@@ -217,12 +218,13 @@ func (o *Command) FlagCounter(short string, long string, opts *Options) *int {
 	var result int
 
 	a := &arg{
-		result: &result,
-		sname:  short,
-		lname:  long,
-		size:   1,
-		opts:   opts,
-		unique: false,
+		result:  &result,
+		sname:   short,
+		lname:   long,
+		size:    1,
+		opts:    opts,
+		unique:  false,
+		argType: FlagCounter,
 	}
 
 	if err := o.addArg(a); err != nil {
@@ -239,12 +241,13 @@ func (o *Command) String(short string, long string, opts *Options) *string {
 	var result string
 
 	a := &arg{
-		result: &result,
-		sname:  short,
-		lname:  long,
-		size:   2,
-		opts:   opts,
-		unique: true,
+		result:  &result,
+		sname:   short,
+		lname:   long,
+		size:    2,
+		opts:    opts,
+		unique:  true,
+		argType: String,
 	}
 
 	if err := o.addArg(a); err != nil {
@@ -262,12 +265,13 @@ func (o *Command) Int(short string, long string, opts *Options) *int {
 	var result int
 
 	a := &arg{
-		result: &result,
-		sname:  short,
-		lname:  long,
-		size:   2,
-		opts:   opts,
-		unique: true,
+		result:  &result,
+		sname:   short,
+		lname:   long,
+		size:    2,
+		opts:    opts,
+		unique:  true,
+		argType: Int,
 	}
 
 	if err := o.addArg(a); err != nil {
@@ -285,12 +289,13 @@ func (o *Command) Float(short string, long string, opts *Options) *float64 {
 	var result float64
 
 	a := &arg{
-		result: &result,
-		sname:  short,
-		lname:  long,
-		size:   2,
-		opts:   opts,
-		unique: true,
+		result:  &result,
+		sname:   short,
+		lname:   long,
+		size:    2,
+		opts:    opts,
+		unique:  true,
+		argType: Float,
 	}
 
 	if err := o.addArg(a); err != nil {
@@ -319,6 +324,7 @@ func (o *Command) File(short string, long string, flag int, perm os.FileMode, op
 		unique:   true,
 		fileFlag: flag,
 		filePerm: perm,
+		argType:  File,
 	}
 
 	if err := o.addArg(a); err != nil {
@@ -345,12 +351,13 @@ func (o *Command) StringList(short string, long string, opts *Options) *[]string
 	result := make([]string, 0)
 
 	a := &arg{
-		result: &result,
-		sname:  short,
-		lname:  long,
-		size:   2,
-		opts:   opts,
-		unique: false,
+		result:  &result,
+		sname:   short,
+		lname:   long,
+		size:    2,
+		opts:    opts,
+		unique:  false,
+		argType: StringList,
 	}
 
 	if err := o.addArg(a); err != nil {
@@ -368,12 +375,13 @@ func (o *Command) IntList(short string, long string, opts *Options) *[]int {
 	result := make([]int, 0)
 
 	a := &arg{
-		result: &result,
-		sname:  short,
-		lname:  long,
-		size:   2,
-		opts:   opts,
-		unique: false,
+		result:  &result,
+		sname:   short,
+		lname:   long,
+		size:    2,
+		opts:    opts,
+		unique:  false,
+		argType: IntList,
 	}
 
 	if err := o.addArg(a); err != nil {
@@ -391,12 +399,13 @@ func (o *Command) FloatList(short string, long string, opts *Options) *[]float64
 	result := make([]float64, 0)
 
 	a := &arg{
-		result: &result,
-		sname:  short,
-		lname:  long,
-		size:   2,
-		opts:   opts,
-		unique: false,
+		result:  &result,
+		sname:   short,
+		lname:   long,
+		size:    2,
+		opts:    opts,
+		unique:  false,
+		argType: FloatList,
 	}
 
 	if err := o.addArg(a); err != nil {
@@ -422,6 +431,7 @@ func (o *Command) FileList(short string, long string, flag int, perm os.FileMode
 		unique:   false,
 		fileFlag: flag,
 		filePerm: perm,
+		argType:  FileList,
 	}
 
 	if err := o.addArg(a); err != nil {
@@ -448,6 +458,7 @@ func (o *Command) Selector(short string, long string, options []string, opts *Op
 		opts:     opts,
 		unique:   true,
 		selector: &options,
+		argType:  Selector,
 	}
 
 	if err := o.addArg(a); err != nil {

argparse_test.go

@@ -1986,7 +1986,7 @@ func TestFlagDefaultValuePass(t *testing.T) {
 
 	p := NewParser("progname", "Prog description")
 
-	f := p.Flag("f", "flag", &Options{Default: true})
+	f := p.Flag("f", "flag", &Options{Default: false})
 
 	err := p.Parse(testArgs)
 
@@ -1995,24 +1995,29 @@ func TestFlagDefaultValuePass(t *testing.T) {
 		t.Error(err.Error())
 	}
 
-	// Should fail if not true
-	if *f != true {
-		t.Errorf("expected [true], got [%t]", *f)
+	// Should fail if not false
+	if *f != false {
+		t.Errorf("expected [false] but found [%t]", *f)
 	}
 }
 
-func TestFlagDefaultValueFail(t *testing.T) {
+func TestFlagDefaultValueShouldIgnoreTrue(t *testing.T) {
 	testArgs := []string{"progname"}
 
 	p := NewParser("progname", "Prog description")
 
-	_ = p.Flag("f", "flag", &Options{Default: "string"})
+	f := p.Flag("f", "flag", &Options{Default: true})
 
 	err := p.Parse(testArgs)
 
-	// Should pass on failure
-	if err == nil || err.Error() != "cannot use default type [string] as value of pointer with type [*bool]" {
-		t.Errorf("Test %s failed: expected error [%s], got error [%+v]", t.Name(), "cannot use default type [string] as value of pointer with type [*bool]", err)
+	// Should fail on failure
+	if err != nil {
+		t.Error(err.Error())
+	}
+
+	// Should fail if not false
+	if *f != false {
+		t.Errorf("expected [false] but found [%t]", *f)
 	}
 }
 
@@ -2042,7 +2047,7 @@ func TestStringDefaultValueFail(t *testing.T) {
 
 	p := NewParser("progname", "Prog description")
 
-	_ = p.String("s", "string", &Options{Default: false})
+	_ = p.String("s", "string", &Options{Default: true})
 
 	err := p.Parse(testArgs)
 

argument.go

@@ -9,20 +9,38 @@ import (
 )
 
 type arg struct {
-	result   interface{} // Pointer to the resulting value
-	opts     *Options    // Options
-	sname    string      // Short name (in Parser will start with "-"
-	lname    string      // Long name (in Parser will start with "--"
-	size     int         // Size defines how many args after match will need to be consumed
-	unique   bool        // Specifies whether flag should be present only ones
-	parsed   bool        // Specifies whether flag has been parsed already
-	fileFlag int         // File mode to open file with
-	filePerm os.FileMode // File permissions to set a file
-	selector *[]string   // Used in Selector type to allow to choose only one from list of options
-	parent   *Command    // Used to get access to specific Command
-	eqChar   bool        // This is used if the command is passed in with an equals char as a seperator
+	result   interface{}  // Pointer to the resulting value
+	opts     *Options     // Options
+	sname    string       // Short name (in Parser will start with "-"
+	lname    string       // Long name (in Parser will start with "--"
+	size     int          // Size defines how many args after match will need to be consumed
+	unique   bool         // Specifies whether flag should be present only ones
+	parsed   bool         // Specifies whether flag has been parsed already
+	fileFlag int          // File mode to open file with
+	filePerm os.FileMode  // File permissions to set a file
+	selector *[]string    // Used in Selector type to allow to choose only one from list of options
+	parent   *Command     // Used to get access to specific Command
+	eqChar   bool         // This is used if the command is passed in with an equals char as a seperator
+	argType  ArgumentType // Used to determine which argument type this is
 }
 
+// enum used to determine the argument type
+type ArgumentType int
+
+const (
+	Flag        ArgumentType = 0
+	FlagCounter              = 1
+	String                   = 2
+	Int                      = 3
+	Float                    = 4
+	File                     = 5
+	StringList               = 6
+	IntList                  = 7
+	FloatList                = 8
+	FileList                 = 9
+	Selector                 = 10
+)
+
 // Arg interface provides exporting of arg structure, while exposing it
 type Arg interface {
 	GetOpts() *Options
@@ -506,7 +524,11 @@ func (o *arg) setDefault() error {
 			if reflect.TypeOf(o.result) != reflect.PtrTo(reflect.TypeOf(o.opts.Default)) {
 				return fmt.Errorf("cannot use default type [%T] as value of pointer with type [%T]", o.opts.Default, o.result)
 			}
-			reflect.ValueOf(o.result).Elem().Set(reflect.ValueOf(o.opts.Default))
+			defaultValue := o.opts.Default
+			if o.argType == Flag && defaultValue == true {
+				defaultValue = false
+			}
+			reflect.ValueOf(o.result).Elem().Set(reflect.ValueOf(defaultValue))
 
 		case *os.File:
 			if err := o.setDefaultFile(); err != nil {