Merge pull request #542 from mhmxs/patch-1

Display error instead of just say command is incorrect

app.go

@@ -194,7 +194,7 @@ func (a *App) Run(arguments []string) (err error) {
 			HandleExitCoder(err)
 			return err
 		}
-		fmt.Fprintf(a.Writer, "%s\n\n", "Incorrect Usage.")
+		fmt.Fprintf(a.Writer, "%s %s\n\n", "Incorrect Usage.", err.Error())
 		ShowAppHelp(context)
 		return err
 	}
@@ -315,7 +315,7 @@ func (a *App) RunAsSubcommand(ctx *Context) (err error) {
 			HandleExitCoder(err)
 			return err
 		}
-		fmt.Fprintf(a.Writer, "%s\n\n", "Incorrect Usage.")
+		fmt.Fprintf(a.Writer, "%s %s\n\n", "Incorrect Usage.", err.Error())
 		ShowSubcommandHelp(context)
 		return err
 	}

app_test.go

@@ -252,6 +252,23 @@ func TestApp_RunAsSubcommandParseFlags(t *testing.T) {
 	expect(t, context.String("lang"), "spanish")
 }
 
+func TestApp_RunAsSubCommandIncorrectUsage(t *testing.T) {
+	a := App{
+		Flags: []Flag{
+			StringFlag{Name: "--foo"},
+		},
+		Writer: bytes.NewBufferString(""),
+	}
+
+	set := flag.NewFlagSet("", flag.ContinueOnError)
+	set.Parse([]string{"", "---foo"})
+	c := &Context{flagSet: set}
+
+	err := a.RunAsSubcommand(c)
+
+	expect(t, err, errors.New("bad flag syntax: ---foo"))
+}
+
 func TestApp_CommandWithFlagBeforeTerminator(t *testing.T) {
 	var parsedOption string
 	var args []string

command.go

@@ -138,7 +138,7 @@ func (c Command) Run(ctx *Context) (err error) {
 			HandleExitCoder(err)
 			return err
 		}
-		fmt.Fprintln(ctx.App.Writer, "Incorrect Usage.")
+		fmt.Fprintln(ctx.App.Writer, "Incorrect Usage:", err.Error())
 		fmt.Fprintln(ctx.App.Writer)
 		ShowCommandHelp(ctx, c.Name)
 		return err