Fix:(issue_1293) Wrap usage text for commands (#1460)

* Fix:(issue_1293) Wrap usage text for commands

* Change way to calculate offset

* Make test case more robust

* Remove add function

* Add comment

help.go

@@ -295,12 +295,14 @@ func printHelpCustom(out io.Writer, templ string, data interface{}, customFuncs
 	const maxLineLength = 10000
 
 	funcMap := template.FuncMap{
-		"join":    strings.Join,
+		"join":           strings.Join,
-		"indent":  indent,
+		"subtract":       subtract,
-		"nindent": nindent,
+		"indent":         indent,
-		"trim":    strings.TrimSpace,
+		"nindent":        nindent,
-		"wrap":    func(input string, offset int) string { return wrap(input, offset, maxLineLength) },
+		"trim":           strings.TrimSpace,
-		"offset":  offset,
+		"wrap":           func(input string, offset int) string { return wrap(input, offset, maxLineLength) },
+		"offset":         offset,
+		"offsetCommands": offsetCommands,
 	}
 
 	if customFuncs["wrapAt"] != nil {
@@ -416,6 +418,10 @@ func checkCommandCompletions(c *Context, name string) bool {
 	return true
 }
 
+func subtract(a, b int) int {
+	return a - b
+}
+
 func indent(spaces int, v string) string {
 	pad := strings.Repeat(" ", spaces)
 	return pad + strings.Replace(v, "\n", "\n"+pad, -1)
@@ -476,3 +482,28 @@ func wrapLine(input string, offset int, wrapAt int, padding string) string {
 func offset(input string, fixed int) int {
 	return len(input) + fixed
 }
+
+// this function tries to find the max width of the names column
+// so say we have the following rows for help
+//
+//	foo1, foo2, foo3  some string here
+//	bar1, b2 some other string here
+//
+// We want to offset the 2nd row usage by some amount so that everything
+// is aligned
+//
+//	foo1, foo2, foo3  some string here
+//	bar1, b2          some other string here
+//
+// to find that offset we find the length of all the rows and use the max
+// to calculate the offset
+func offsetCommands(cmds []*Command, fixed int) int {
+	var max int = 0
+	for _, cmd := range cmds {
+		s := strings.Join(cmd.Names(), ", ")
+		if len(s) > max {
+			max = len(s)
+		}
+	}
+	return max + fixed
+}

help_test.go

@@ -895,6 +895,42 @@ App UsageText`,
 	}
 }
 
+func TestShowAppHelp_CommandMultiLine_UsageText(t *testing.T) {
+	app := &App{
+		UsageText: `This is a
+multi
+line
+App UsageText`,
+		Commands: []*Command{
+			{
+				Name:    "frobbly",
+				Aliases: []string{"frb1", "frbb2", "frl2"},
+				Usage:   "this is a long help output for the run command, long usage \noutput, long usage output, long usage output, long usage output\noutput, long usage output, long usage output",
+			},
+			{
+				Name:    "grobbly",
+				Aliases: []string{"grb1", "grbb2"},
+				Usage:   "this is another long help output for the run command, long usage \noutput, long usage output",
+			},
+		},
+	}
+
+	output := &bytes.Buffer{}
+	app.Writer = output
+
+	_ = app.Run([]string{"foo"})
+
+	expected := "COMMANDS:\n" +
+		"   frobbly, frb1, frbb2, frl2  this is a long help output for the run command, long usage \n" +
+		"                               output, long usage output, long usage output, long usage output\n" +
+		"                               output, long usage output, long usage output\n" +
+		"   grobbly, grb1, grbb2        this is another long help output for the run command, long usage \n" +
+		"                               output, long usage output"
+	if !strings.Contains(output.String(), expected) {
+		t.Errorf("expected output to include usage text; got: %q", output.String())
+	}
+}
+
 func TestHideHelpCommand(t *testing.T) {
 	app := &App{
 		HideHelpCommand: true,

template.go

@@ -21,8 +21,8 @@ AUTHOR{{with $length := len .Authors}}{{if ne 1 $length}}S{{end}}{{end}}:
 
 COMMANDS:{{range .VisibleCategories}}{{if .Name}}
    {{.Name}}:{{range .VisibleCommands}}
-     {{join .Names ", "}}{{"\t"}}{{.Usage}}{{end}}{{else}}{{range .VisibleCommands}}
+     {{join .Names ", "}}{{"\t"}}{{.Usage}}{{end}}{{else}}{{ $cv := offsetCommands .VisibleCommands 5}}{{range .VisibleCommands}}
-   {{join .Names ", "}}{{"\t"}}{{.Usage}}{{end}}{{end}}{{end}}{{end}}{{if .VisibleFlagCategories}}
+   {{$s := join .Names ", "}}{{$s}}{{ $sp := subtract $cv (offset $s 3) }}{{ indent $sp ""}}{{wrap .Usage $cv}}{{end}}{{end}}{{end}}{{end}}{{if .VisibleFlagCategories}}
 
 GLOBAL OPTIONS:{{range .VisibleFlagCategories}}
    {{if .Name}}{{.Name}}
@@ -76,8 +76,8 @@ DESCRIPTION:
 
 COMMANDS:{{range .VisibleCategories}}{{if .Name}}
    {{.Name}}:{{range .VisibleCommands}}
-     {{join .Names ", "}}{{"\t"}}{{.Usage}}{{end}}{{else}}{{range .VisibleCommands}}
+     {{join .Names ", "}}{{"\t"}}{{.Usage}}{{end}}{{else}}{{ $cv := offsetCommands .VisibleCommands 5}}{{range .VisibleCommands}}
-   {{join .Names ", "}}{{"\t"}}{{.Usage}}{{end}}{{end}}{{end}}{{if .VisibleFlags}}
+     {{$s := join .Names ", "}}{{$s}}{{ $sp := subtract $cv (offset $s 3) }}{{ indent $sp ""}}{{wrap .Usage $cv}}{{end}}{{end}}{{end}}{{if .VisibleFlags}}
 
 OPTIONS:
    {{range .VisibleFlags}}{{.}}