add some unit test. fix: repeat display error message

_examples/alone/alone.go

@@ -37,6 +37,6 @@ func main() {
 	}
 
 	// Alone Running
-	cmd.Run(nil)
+	cmd.MustRun(nil)
 	// cmd.Run(os.Args[1:])
 }

_examples/cmd/example.go

@@ -21,11 +21,12 @@ func (ns *Names) Set(value string) error {
 
 // options for the command
 var exampleOpts = struct {
-	id    int
-	c     string
-	dir   string
-	opt   string
-	names Names
+	id      int
+	c       string
+	dir     string
+	opt     string
+	showErr bool
+	names   Names
 }{}
 
 // ExampleCommand command definition
@@ -42,6 +43,7 @@ func ExampleCommand() *gcli.Command {
 
 	// bind options
 	cmd.IntOpt(&exampleOpts.id, "id", "", 2, "the id option")
+	cmd.BoolOpt(&exampleOpts.showErr, "err", "e", false, "display error example")
 	cmd.StrOpt(&exampleOpts.c, "config", "c", "value", "the config option")
 	// notice `DIRECTORY` will replace to option value type
 	cmd.StrOpt(&exampleOpts.dir, "dir", "d", "", "the `DIRECTORY` option")
@@ -65,6 +67,10 @@ func ExampleCommand() *gcli.Command {
 func exampleExecute(c *gcli.Command, args []string) error {
 	fmt.Print("hello, in example command\n")
 
+	if exampleOpts.showErr {
+		return c.Errorf("OO, An error has occurred!!")
+	}
+
 	magentaln := color.Magenta.Println
 
 	magentaln("All options:")

app.go

@@ -66,7 +66,7 @@ type App struct {
 	// Strict use strict mode.
 	// If True:
 	// 	- short opt must be begin '-', long opt must be begin '--'
-	//	- will check invalid arguments, like to many arguments
+	// 	- will check invalid arguments, like to many arguments
 	Strict bool
 	// vars you can add some vars map for render help info
 	// vars map[string]string

cmd.go

@@ -151,8 +151,13 @@ func (c *Command) initialize() *Command {
 
 	c.Fire(EvtInit, nil)
 
-	// add default error handler.
-	c.SimpleHooks.Add(EvtError, defaultErrHandler)
+	// if not set application instance
+	if c.app == nil {
+		// mark is alone
+		c.alone = true
+		// add default error handler.
+		c.SimpleHooks.Add(EvtError, defaultErrHandler)
+	}
 
 	// init for Flags
 	c.Flags.Init(c.Name, flag.ContinueOnError)

cmd_run.go

@@ -35,12 +35,15 @@ func (c *Command) Execute(args []string) (err error) {
 	}
 
 	if err != nil {
-		c.app.AddError(err)
+		// if run in application, report error to app.
+		if !c.alone {
+			c.app.AddError(err)
+		}
+
 		c.Fire(EvtError, err)
 	} else {
 		c.Fire(EvtAfter, nil)
 	}
-
 	return
 }
 
@@ -49,7 +52,7 @@ func (c *Command) collectNamedArgs(inArgs []string) error {
 	inNum := len(inArgs)
 
 	for i, arg := range c.args {
-		num = i + 1      // num is equal index + 1
+		num = i + 1 // num is equal index + 1
 		if num > inNum { // no enough arg
 			if arg.Required {
 				return fmt.Errorf("must set value for the argument: %s (position %d)", arg.ShowName, arg.index)
@@ -100,15 +103,19 @@ func (c *Command) Copy() *Command {
  * alone running
  *************************************************************/
 
+// MustRun the current command
+func (c *Command) MustRun(inArgs []string) {
+	if err := c.Run(inArgs); err != nil {
+		panic(err)
+	}
+}
+
 // Run the current command
-func (c *Command) Run(inArgs []string) {
+func (c *Command) Run(inArgs []string) error {
 	if c.app == nil {
 		// don't display date on print log
 		log.SetFlags(0)
 
-		// mark is alone
-		c.alone = true
-
 		// init the command
 		c.initialize()
 
@@ -125,7 +132,7 @@ func (c *Command) Run(inArgs []string) {
 		inArgs = c.Flags.Args()
 	}
 
-	_ = c.Execute(inArgs)
+	return c.Execute(inArgs)
 }
 
 /*************************************************************

cmd_test.go

@@ -1 +1,67 @@
 package gcli_test
+
+import (
+	"testing"
+
+	"github.com/gookit/gcli"
+	"github.com/stretchr/testify/assert"
+)
+
+var simpleArgs = []string{"hi"}
+
+func TestNewCommand(t *testing.T) {
+	ris := assert.New(t)
+
+	c := gcli.NewCommand("test", "desc test", func(c *gcli.Command) {
+		c.Aliases = []string{"alias1", "alias2"}
+	})
+
+	ris.NotEmpty(c)
+	ris.Nil(c.App())
+
+	err := c.Run(simpleArgs)
+	ris.NoError(err)
+	ris.True(c.IsAlone())
+	ris.False(c.NotAlone())
+
+	// ris.Equal("", c.ArgLine())
+	ris.Equal("alias1,alias2", c.AliasesString())
+	ris.Equal("alias1alias2", c.AliasesString(""))
+}
+
+func TestCommand_Errorf(t *testing.T) {
+	ris := assert.New(t)
+
+	c := gcli.NewCommand("test", "desc test", nil)
+	c.SetFunc(func(c *gcli.Command, args []string) error {
+		return c.Errorf("error message")
+	})
+
+	ris.NotEmpty(c)
+
+	err := c.Run(simpleArgs)
+	ris.Error(err)
+	ris.Equal("error message", err.Error())
+
+	ris.Panics(func() {
+		c.MustRun(simpleArgs)
+	})
+}
+
+func TestCommand_Run(t *testing.T) {
+	ris := assert.New(t)
+
+	c := gcli.NewCommand("test", "desc test", func(c *gcli.Command) {
+		ris.Equal("test", c.Name)
+		c.Aliases = []string{"alias1"}
+	})
+	c.SetFunc(func(c *gcli.Command, args []string) error {
+		return nil
+	})
+
+	ris.NotEmpty(c)
+	err := c.Run(simpleArgs)
+	ris.NoError(err)
+
+	ris.Equal("alias1", c.AliasesString(""))
+}

helper/download.go

@@ -117,7 +117,7 @@ func printDownloadPercent(done chan int64, path string, total int64) {
 
 	for {
 		select {
-		case <-done: // end
+		case <-done:      // end
 			fmt.Println() // output newline
 			return
 		default: