Add new test

help_test.go

@@ -1520,3 +1520,68 @@ OPTIONS:
 			output.String(), expected)
 	}
 }
+
+func TestCategorizedHelp(t *testing.T) {
+	// Reset HelpPrinter after this test.
+	defer func(old helpPrinter) {
+		HelpPrinter = old
+	}(HelpPrinter)
+
+	output := new(bytes.Buffer)
+	app := &App{
+		Name:   "cli.test",
+		Writer: output,
+		Action: func(ctx *Context) error { return nil },
+		Flags: []Flag{
+			&StringFlag{
+				Name: "strd", // no category set
+			},
+			&Int64Flag{
+				Name:     "intd",
+				Aliases:  []string{"altd1", "altd2"},
+				Category: "cat1",
+			},
+		},
+	}
+
+	c := NewContext(app, nil, nil)
+	app.Setup()
+
+	HelpPrinter = func(w io.Writer, templ string, data interface{}) {
+		funcMap := map[string]interface{}{
+			"wrapAt": func() int {
+				return 30
+			},
+		}
+
+		HelpPrinterCustom(w, templ, data, funcMap)
+	}
+
+	_ = ShowAppHelp(c)
+
+	expected := `NAME:
+   cli.test - A new cli
+              application
+
+USAGE:
+   cli.test [global options] command [command options] [arguments...]
+
+COMMANDS:
+   help, h  Shows a list of
+            commands or help
+            for one command
+
+GLOBAL OPTIONS:
+   --help, -h    show help
+   --strd value  
+
+   cat1
+
+   --intd value, --altd1 value, --altd2 value  (default: 0)
+
+`
+	if output.String() != expected {
+		t.Errorf("Unexpected wrapping, got:\n%s\nexpected:\n%s",
+			output.String(), expected)
+	}
+}