Custom help (#50)

* Finishes addressing issue #29

Adds a Settings struct for creating parsers/commands with
NewParserWithSettings or NewCommandWithSettings.

Settings
	HelpDisabled -	defaults false, set true to not generate a help
			argument for parser/command
	HelpSname -	short name for the parser/command help argument.
			Can be left empty
	HelpLname -	long name for the parser/command help argument.
			Leaving empty forces use of -h/--help when
			HelpDisabled is false
	NoExitOnHelp -	defaults false, set true to not exit on help
			argument being parsed

Should resolve all outstanding help argument issues.

* Finishing Issue #29

Fixed merge conflict error due to check function return type change confusion.

* Updated Settings Object to multiple function calls

Added functions:
	DisableHelp
	SetHelp
	ExitOnHelp

Added Command.exitOnHelp

Added more tests to increase code coverage

* Updated no help example

argparse.go

@@ -23,6 +23,7 @@ type Command struct {
 	happened    bool
 	parent      *Command
 	HelpFunc    func(c *Command, msg interface{}) string
+	exitOnHelp  bool
 }
 
 // GetName exposes Command's name field
@@ -109,7 +110,8 @@ func NewParser(name string, description string) *Parser {
 	p.args = make([]*arg, 0)
 	p.commands = make([]*Command, 0)
 
-	p.help()
+	p.help("h", "help")
+	p.exitOnHelp = true
 	p.HelpFunc = (*Command).Usage
 
 	return p
@@ -128,8 +130,7 @@ func (o *Command) NewCommand(name string, description string) *Command {
 	c.description = description
 	c.parsed = false
 	c.parent = o
-
-	c.help()
+	c.exitOnHelp = o.exitOnHelp
 
 	if o.commands == nil {
 		o.commands = make([]*Command, 0)
@@ -140,6 +141,30 @@ func (o *Command) NewCommand(name string, description string) *Command {
 	return c
 }
 
+// DisableHelp removes any help arguments from the commands list of arguments
+// This prevents prevents help from being parsed or invoked from the argument list
+func (o *Parser) DisableHelp() {
+	for i, arg := range o.args {
+		if _, ok := arg.result.(*help); ok {
+			o.args = append(o.args[:i], o.args[i+1:]...)
+		}
+	}
+}
+
+// ExitOnHelp sets the exitOnHelp variable of Parser
+func (o *Command) ExitOnHelp(b bool) {
+	o.exitOnHelp = b
+	for _, c := range o.commands {
+		c.ExitOnHelp(b)
+	}
+}
+
+// SetHelp removes the previous help argument, and creates a new one with the desired sname/lname
+func (o *Parser) SetHelp(sname, lname string) {
+	o.DisableHelp()
+	o.help(sname, lname)
+}
+
 // Flag Creates new flag type of argument, which is boolean value showing if argument was provided or not.
 // Takes short name, long name and pointer to options (optional).
 // Short name must be single character, but can be omitted by giving empty string.

argparse_examples_test.go

@@ -1,6 +1,8 @@
 package argparse
 
-import "fmt"
+import (
+	"fmt"
+)
 
 func ExampleCommand_Help() {
 	parser := NewParser("parser", "")

argparse_test.go

@@ -2282,9 +2282,192 @@ func TestUsageStringer(t *testing.T) {
 	}
 }
 
-func TestNewParserHelpFuncDefault(t *testing.T) {
+func TestParserHelpFuncDefault(t *testing.T) {
 	parser := NewParser("parser", "")
 	if parser.HelpFunc == nil || parser.Help(nil) != parser.Usage(nil) {
 		t.Errorf("HelpFunc should default to Usage function")
 	}
 }
+
+func TestCommandHelpFuncDefault(t *testing.T) {
+	parser := NewParser("parser", "")
+	command := parser.NewCommand("command", "")
+	if command.HelpFunc != nil {
+		t.Errorf("HelpFunc should default to Usage function")
+	}
+}
+
+func TestCommandHelpFuncDefaultToParent(t *testing.T) {
+	parser := NewParser("parser", "")
+	command := parser.NewCommand("command", "")
+
+	parser.HelpFunc = func(c *Command, msg interface{}) string {
+		return "testing"
+	}
+
+	if command.Help(nil) == command.Usage(nil) || command.Help(nil) != parser.Help(nil) {
+		t.Errorf("command HelpFunc should default to parent function")
+	}
+}
+
+func TestParserExitOnHelpTrue(t *testing.T) {
+	exited := false
+	exit = func(n int) {
+		exited = true
+	}
+
+	parser := NewParser("parser", "")
+
+	print = func(...interface{}) (int, error) {
+		return 0, nil
+	}
+
+	if err := parser.Parse([]string{"parser", "-h"}); err == nil {
+		if !exited {
+			t.Errorf("Parsing help should have invoked os.Exit")
+		}
+	} else {
+		t.Error(err)
+	}
+}
+
+func TestParserExitOnHelpFalse(t *testing.T) {
+	exited := false
+	exit = func(n int) {
+		exited = true
+	}
+
+	parser := NewParser("parser", "")
+	parser.ExitOnHelp(false)
+
+	print = func(...interface{}) (int, error) {
+		return 0, nil
+	}
+
+	if err := parser.Parse([]string{"parser", "-h"}); exited {
+		t.Errorf("Parsing help should not have invoked os.Exit")
+	} else if err != nil {
+		t.Error(err)
+	}
+}
+
+func TestParserDisableHelp(t *testing.T) {
+	parser := NewParser("parser", "")
+	parser.DisableHelp()
+	if len(parser.args) > 0 {
+		t.Errorf("Parser should not have any arguments")
+	}
+
+	print = func(...interface{}) (int, error) {
+		return 0, nil
+	}
+
+	if err := parser.Parse([]string{"parser", "-h"}); err == nil {
+		t.Errorf("Parsing should fail, help argument shouldn't exist")
+	}
+}
+
+func TestParserSetHelp(t *testing.T) {
+	sname, lname := "x", "xyz"
+	parser := NewParser("parser", "")
+	parser.SetHelp(sname, lname)
+	if len(parser.args) != 1 {
+		t.Errorf("Parser should have one argument:\n%s", parser.Help(nil))
+	}
+	arg := parser.args[0]
+	if _, ok := arg.result.(*help); !ok {
+		t.Errorf("Argument should be %T, is %T", help{}, arg.result)
+	}
+	if arg.sname != sname {
+		t.Errorf("Argument short name should be %s, is %s", sname, arg.sname)
+	}
+	if arg.lname != lname {
+		t.Errorf("Argument long name should be %s, is %s", lname, arg.lname)
+	}
+}
+
+func TestCommandExitOnHelpTrue(t *testing.T) {
+	exited := false
+	exit = func(n int) {
+		exited = true
+	}
+
+	parser := NewParser("parser", "")
+	parser.NewCommand("command", "")
+
+	print = func(...interface{}) (int, error) {
+		return 0, nil
+	}
+
+	if err := parser.Parse([]string{"parser", "command", "-h"}); exited {
+		if err != nil {
+			t.Error(err)
+		}
+	} else {
+		t.Errorf("Parsing help should have invoked os.Exit")
+	}
+}
+
+func TestCommandExitOnHelpFalse(t *testing.T) {
+	exited := false
+	exit = func(n int) {
+		exited = true
+	}
+
+	parser := NewParser("parser", "")
+	parser.NewCommand("command", "")
+	parser.ExitOnHelp(false)
+
+	print = func(...interface{}) (int, error) {
+		return 0, nil
+	}
+
+	if err := parser.Parse([]string{"parser", "command", "-h"}); exited {
+		t.Error("Parsing help should not have exited")
+	} else if err != nil {
+		t.Error(err)
+	}
+}
+
+func TestCommandDisableHelp(t *testing.T) {
+	parser := NewParser("parser", "")
+	parser.NewCommand("command", "")
+	parser.DisableHelp()
+	if len(parser.args) > 0 {
+		t.Errorf("Parser should not have any arguments")
+	}
+
+	print = func(...interface{}) (int, error) {
+		return 0, nil
+	}
+
+	if err := parser.Parse([]string{"parser", "command", "-h"}); err == nil {
+		t.Errorf("Parsing should fail, help argument shouldn't exist")
+	}
+}
+
+func TestCommandHelpInheritance(t *testing.T) {
+	parser := NewParser("parser", "")
+	command := parser.NewCommand("command", "")
+	parser.ExitOnHelp(false)
+
+	if command.exitOnHelp != false {
+		t.Errorf("Command should inherit exitOnHelp from parent, even after creation")
+	}
+}
+
+func TestCommandHelpSetSnameOnly(t *testing.T) {
+	parser := NewParser("parser", "")
+	parser.SetHelp("q", "")
+
+	arg := parser.args[0]
+
+	_, ok := arg.result.(*help)
+	if !ok {
+		t.Error("Argument should be of help type")
+	}
+
+	if arg.sname != "h" || arg.lname != "help" {
+		t.Error("Help arugment names should have defaulted")
+	}
+}

argument.go

@@ -98,13 +98,6 @@ func (o *arg) checkShortName(argument string) (int, error) {
 // For shorthand argument - 0 if there is no occurrences, or count of occurrences.
 // Shorthand argument with parametr, mast be the only or last in the argument string.
 func (o *arg) check(argument string) (int, error) {
-	// Shortcut to showing help
-	if argument == "-h" || argument == "--help" {
-		helpText := o.parent.Help(nil)
-		fmt.Print(helpText)
-		os.Exit(0)
-	}
-
 	rez := o.checkLongName(argument)
 	if rez > 0 {
 		return rez, nil
@@ -334,13 +327,20 @@ func (o *arg) parseFileList(args []string) error {
 	return nil
 }
 
+// To overwrite while testing
+// Possibly extend to allow user overriding
+var exit func(int) = os.Exit
+var print func(...interface{}) (int, error) = fmt.Println
+
 func (o *arg) parseSomeType(args []string, argCount int) error {
 	var err error
 	switch o.result.(type) {
 	case *help:
-		helpText := o.parent.Help(nil)
-		fmt.Print(helpText)
-		os.Exit(0)
+		print(o.parent.Help(nil))
+		if o.parent.exitOnHelp {
+			exit(0)
+		}
+	//data of bool type is for Flag argument
 	case *bool:
 		err = o.parseBool(args)
 	case *int:

command.go

@@ -4,13 +4,17 @@ import (
 	"fmt"
 )
 
-func (o *Command) help() {
+func (o *Command) help(sname, lname string) {
 	result := &help{}
 
+	if lname == "" {
+		sname, lname = "h", "help"
+	}
+
 	a := &arg{
-		result: &result,
-		sname:  "h",
-		lname:  "help",
+		result: result,
+		sname:  sname,
+		lname:  lname,
 		size:   1,
 		opts:   &Options{Help: "Print help information"},
 		unique: true,

examples/help-argument-names/help-argument-names.go

@@ -0,0 +1,19 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/akamensky/argparse"
+)
+
+func main() {
+	// Create new parser object
+	parser := argparse.NewParser("help", "Demonstrates changing the help argument names")
+	parser.SetHelp("e", "example")
+	// Create string flag
+	parser.String("s", "string", &argparse.Options{Required: false, Help: "String argument example"})
+	// Create string flag
+	parser.Int("i", "int", &argparse.Options{Required: false, Help: "Integer argument example"})
+	// Use the help function
+	fmt.Print(parser.Parse([]string{"parser", "-e"}))
+}

examples/help-no-exit/help-no-exit.go

@@ -0,0 +1,20 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/akamensky/argparse"
+)
+
+func main() {
+	// Create new parser object
+	parser := argparse.NewParser("help", "Demonstrates changing the help argument names")
+	parser.ExitOnHelp(false)
+	// Create string flag
+	parser.String("s", "string", &argparse.Options{Required: false, Help: "String argument example"})
+	// Create string flag
+	parser.Int("i", "int", &argparse.Options{Required: false, Help: "Integer argument example"})
+	// Use the help function
+	fmt.Println(parser.Parse([]string{"parser", "-h"}))
+	fmt.Println("Didn't exit, still printing")
+}

examples/no-help/no-help.go

@@ -0,0 +1,20 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/akamensky/argparse"
+)
+
+func main() {
+	// Create new parser object
+	parser := argparse.NewParser("help", "Demonstrates disabing the help arguments")
+	parser.DisableHelp()
+	// Create string flag
+	parser.String("s", "string", &argparse.Options{Required: false, Help: "String argument example"})
+	// Create string flag
+	parser.Int("i", "int", &argparse.Options{Required: false, Help: "Integer argument example"})
+
+	// parsing for -h fails
+	fmt.Println(parser.Parse([]string{"parser", "-h", "--help", "-s", "testing", "-i", "5"}))
+}