Like what is already possible for 'Before' actions, get 'Actions' to …

…return on

exit, so that app.Run() gets to catch  all errors, if any, underneath it.
This commit induces a minor API break. [ for the sake of perfection, the tests
would need to be extended a bit for full coverage. ]

README.md

@@ -1,5 +1,9 @@
 [![Build Status](https://travis-ci.org/codegangsta/cli.png?branch=master)](https://travis-ci.org/codegangsta/cli)
 
+this is a patched version, with some additional features i found usefull, from [github.com/codegangsta/cli](github.com/codegangsta/cli). ideally those features will be merged upstream some day.
+
+---
+
 # cli.go
 cli.go is simple, fast, and fun package for building command line apps in Go. The goal is to enable developers to write fast and distributable command line applications in an expressive way.
 
@@ -54,11 +58,13 @@ func main() {
   app := cli.NewApp()
   app.Name = "boom"
   app.Usage = "make an explosive entrance"
-  app.Action = func(c *cli.Context) {
+  app.Action = func(c *cli.Context) (err error) {
     println("boom! I say!")
+    ...
+    return err
   }
 
-  app.Run(os.Args)
+  err := app.Run(os.Args)
 }
 ```
 
@@ -90,8 +96,10 @@ func main() {
   app.License = "ASL-2 (Apache Software License version 2.0) <http://www.apache.org/licenses/LICENSE-2.0>"
   // if ommited nothig will be printed
   app.Reporting = "Report bugs to me, if you find any :-) ..."
-  app.Action = func(c *cli.Context) {
+  app.Action = func(c *cli.Context) (err error) {
     println("Hello friend!")
+    ...
+    return err
   }
   app.Run(os.Args)
 }
@@ -145,8 +153,10 @@ You can lookup arguments by calling the `Args` function on cli.Context.
 
 ``` go
 ...
-app.Action = func(c *cli.Context) {
+app.Action = func(c *cli.Context) (err error) {
   println("Hello", c.Args()[0])
+  ...
+  return err
 }
 ...
 ```
@@ -158,7 +168,7 @@ Setting and querying flags is simple.
 app.Flags = []cli.Flag {
   cli.StringFlag{"lang", "english", "language for the greeting"},
 }
-app.Action = func(c *cli.Context) {
+app.Action = func(c *cli.Context) (err error){
   name := "someone"
   if len(c.Args()) > 0 {
     name = c.Args()[0]
@@ -170,6 +180,7 @@ app.Action = func(c *cli.Context) {
   }
 }
 ...
+return err
 ```
 
 #### Alternate Names
@@ -194,11 +205,13 @@ app.Flags = []cli.Flag{
       Usage: "enables debug mode",
     },
   }
-app.Action = func(c *cli.Context) {
+app.Action = func(c *cli.Context) (err error) {
     if c.String("debug") == "true" {
       DEBUG = true
       log.Printf("DEBUG mode enabled.")
     }
+    ...
+    return err
   }
 
 ```
@@ -215,16 +228,18 @@ app.Commands = []cli.Command{
     Name:      "add",
     ShortName: "a",
     Usage:     "add a task to the list",
-    Action: func(c *cli.Context) {
+    Action: func(c *cli.Context) (err error) {
       println("added task: ", c.Args().First())
+      return err
     },
   },
   {
     Name:      "complete",
     ShortName: "c",
     Usage:     "complete a task on the list",
-    Action: func(c *cli.Context) {
+    Action: func(c *cli.Context) (err error)  {
       println("completed task: ", c.Args().First())
+      return err
     },
   },
 }

app.go

@@ -25,7 +25,7 @@ type App struct {
 	// If a non-nil error is returned, no subcommands are run
 	Before func(context *Context) error
 	// The action to execute when no subcommands are specified
-	Action func(context *Context)
+	Action func(context *Context) error
 	// Compilation date
 	Compiled time.Time
 	// Author
@@ -126,8 +126,7 @@ func (a *App) Run(arguments []string) error {
 	}
 
 	// Run default Action
-	a.Action(context)
-	return nil
+	return a.Action(context)
 }
 
 // Returns the named command on App. Returns nil if the command does not exist

app_test.go

@@ -2,9 +2,11 @@ package cli_test
 
 import (
 	"fmt"
-	"github.com/codegangsta/cli"
 	"os"
 	"testing"
+
+	"."
+	//"github.com/codegangsta/cli"
 )
 
 func ExampleApp() {
@@ -16,8 +18,9 @@ func ExampleApp() {
 	app.Flags = []cli.Flag{
 		cli.StringFlag{Name: "name", Value: "bob", Usage: "a name to say"},
 	}
-	app.Action = func(c *cli.Context) {
+	app.Action = func(c *cli.Context) (err error) {
 		fmt.Printf("Hello %v\n", c.String("name"))
+		return err
 	}
 	app.Run(os.Args)
 	// Output:
@@ -28,8 +31,9 @@ func TestApp_Run(t *testing.T) {
 	s := ""
 
 	app := cli.NewApp()
-	app.Action = func(c *cli.Context) {
+	app.Action = func(c *cli.Context) (err error) {
 		s = s + c.Args().First()
+		return nil
 	}
 
 	err := app.Run([]string{"command", "foo"})
@@ -74,9 +78,10 @@ func TestApp_CommandWithArgBeforeFlags(t *testing.T) {
 		Flags: []cli.Flag{
 			cli.StringFlag{Name: "option", Value: "", Usage: "some option"},
 		},
-		Action: func(c *cli.Context) {
+		Action: func(c *cli.Context) (err error) {
 			parsedOption = c.String("option")
 			firstArg = c.Args().First()
+			return err
 		},
 	}
 	app.Commands = []cli.Command{command}
@@ -94,8 +99,9 @@ func TestApp_Float64Flag(t *testing.T) {
 	app.Flags = []cli.Flag{
 		cli.Float64Flag{Name: "height", Value: 1.5, Usage: "Set the height, in meters"},
 	}
-	app.Action = func(c *cli.Context) {
+	app.Action = func(c *cli.Context) (err error) {
 		meters = c.Float64("height")
+		return err
 	}
 
 	app.Run([]string{"", "--height", "1.93"})
@@ -114,11 +120,12 @@ func TestApp_ParseSliceFlags(t *testing.T) {
 			cli.IntSliceFlag{Name: "p", Value: &cli.IntSlice{}, Usage: "set one or more ip addr"},
 			cli.StringSliceFlag{Name: "ip", Value: &cli.StringSlice{}, Usage: "set one or more ports to open"},
 		},
-		Action: func(c *cli.Context) {
+		Action: func(c *cli.Context) (err error) {
 			parsedIntSlice = c.IntSlice("p")
 			parsedStringSlice = c.StringSlice("ip")
 			parsedOption = c.String("option")
 			firstArg = c.Args().First()
+			return err
 		},
 	}
 	app.Commands = []cli.Command{command}
@@ -180,8 +187,9 @@ func TestApp_BeforeFunc(t *testing.T) {
 	app.Commands = []cli.Command{
 		cli.Command{
 			Name: "sub",
-			Action: func(c *cli.Context) {
+			Action: func(c *cli.Context) (err error) {
 				subcommandRun = true
+				return err
 			},
 		},
 	}

cli.go

@@ -10,8 +10,9 @@
 //     app := cli.NewApp()
 //     app.Name = "greet"
 //     app.Usage = "say a greeting"
-//     app.Action = func(c *cli.Context) {
+//     app.Action = func(c *cli.Context) (err error) {
 //       println("Greetings")
+//       return err
 //     }
 //
 //     app.Run(os.Args)

command.go

@@ -17,7 +17,7 @@ type Command struct {
 	// A longer explaination of how the command works
 	Description string
 	// The function to call when this command is invoked
-	Action func(context *Context)
+	Action func(context *Context) error
 	// List of flags to parse
 	Flags []Flag
 	// if True command won't be displayed on help
@@ -72,8 +72,7 @@ func (c Command) Run(ctx *Context) error {
 	if checkCommandHelp(context, c.Name) {
 		return nil
 	}
-	c.Action(context)
-	return nil
+	return c.Action(context)
 }
 
 // Returns true if Command.Name or Command.ShortName matches given name

help.go

@@ -58,18 +58,20 @@ var helpCommand = Command{
 	Name:      "help",
 	ShortName: "h",
 	Usage:     "Shows a list of commands or help for one command",
-	Action: func(c *Context) {
+	Action: func(c *Context) (err error) {
 		args := c.Args()
 		if args.Present() {
 			ShowCommandHelp(c, args.First())
 		} else {
 			ShowAppHelp(c)
 		}
+		return err
 	},
 }
 
 // Prints help for the App
 var HelpPrinter = printHelp
+
 func ShowAppHelp(c *Context) {
 	HelpPrinter(AppHelpTemplate, c.App)
 }