Port the show_error kitten to Go

tools/cmd/show_error/main.go

@@ -0,0 +1,114 @@
+// License: GPLv3 Copyright: 2023, Kovid Goyal, <kovid at kovidgoyal.net>
+
+package show_error
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"os"
+
+	"kitty/tools/cli"
+	"kitty/tools/cli/markup"
+	"kitty/tools/tty"
+	"kitty/tools/tui"
+	"kitty/tools/tui/loop"
+)
+
+var _ = fmt.Print
+
+type Options struct {
+	Title string
+}
+
+type Message struct {
+	Msg       string `json:"msg"`
+	Traceback string `json:"tb"`
+}
+
+func main(args []string, opts *Options) (rc int, err error) {
+	if tty.IsTerminal(os.Stdin.Fd()) {
+		return 1, fmt.Errorf("Input data for this kitten must be piped as JSON to STDIN")
+	}
+	data, err := io.ReadAll(os.Stdin)
+	if err != nil {
+		return 1, err
+	}
+	m := Message{}
+	err = json.Unmarshal(data, &m)
+	if err != nil {
+		return 1, err
+	}
+	f := markup.New(true)
+	if opts.Title != "" {
+		fmt.Println(f.Err(opts.Title))
+		fmt.Println()
+	}
+	fmt.Println(m.Msg)
+	show_traceback := false
+	if m.Traceback != "" {
+		lp, err := loop.New(loop.NoAlternateScreen, loop.NoRestoreColors, loop.NoMouseTracking)
+		if err != nil {
+			return 1, err
+		}
+		lp.OnInitialize = func() (string, error) {
+			lp.SetCursorVisible(false)
+			lp.QueueWriteString("\n\r\x1b[1;32mPress e to see detailed traceback or any other key to exit\x1b[m\r\n")
+			return "", nil
+		}
+		lp.OnFinalize = func() string {
+			lp.SetCursorVisible(true)
+			return ""
+		}
+
+		lp.OnKeyEvent = func(event *loop.KeyEvent) error {
+			if event.Type == loop.PRESS || event.Type == loop.REPEAT {
+				if event.MatchesPressOrRepeat("e") || event.MatchesPressOrRepeat("shift+e") || event.MatchesPressOrRepeat("E") {
+					show_traceback = true
+					lp.Quit(0)
+				} else {
+					lp.Quit(1)
+				}
+			}
+			if event.MatchesPressOrRepeat("enter") || event.MatchesPressOrRepeat("kp_enter") || event.MatchesPressOrRepeat("esc") || event.MatchesPressOrRepeat("ctrl+c") || event.MatchesPressOrRepeat("ctrl+d") {
+				event.Handled = true
+				lp.Quit(0)
+			}
+			return nil
+		}
+		lp.Run()
+		if lp.ExitCode() == 1 {
+			return 0, nil
+		}
+	}
+	if show_traceback {
+		fmt.Println(m.Traceback)
+		fmt.Println()
+	}
+	tui.HoldTillEnter(true)
+	return
+}
+
+func EntryPoint(root *cli.Command) *cli.Command {
+	sc := root.AddSubCommand(&cli.Command{
+		Name:             "__show_error__",
+		Hidden:           true,
+		Usage:            "[options]",
+		ShortDescription: "Show an error message. Internal use.",
+		HelpText:         "Show an error message. Used internally by kitty.",
+		Run: func(cmd *cli.Command, args []string) (ret int, err error) {
+			opts := &Options{}
+			err = cmd.GetOptionValues(opts)
+			if err != nil {
+				return 1, err
+			}
+			return main(args, opts)
+		},
+	})
+	sc.Add(cli.OptionSpec{
+		Name:    "--title",
+		Default: "ERROR",
+		Help:    "The title for the error message",
+	})
+	return sc
+}

tools/cmd/tool/main.go

@@ -20,6 +20,7 @@ import (
 	"kitty/tools/cmd/edit_in_kitty"
 	"kitty/tools/cmd/pytest"
 	"kitty/tools/cmd/run_shell"
+	"kitty/tools/cmd/show_error"
 	"kitty/tools/cmd/update_self"
 	"kitty/tools/tui"
 )
@@ -58,6 +59,8 @@ func KittyToolEntryPoints(root *cli.Command) {
 	themes.ParseEntryPoint(root)
 	// run-shell
 	run_shell.EntryPoint(root)
+	// show_error
+	show_error.EntryPoint(root)
 	// __pytest__
 	pytest.EntryPoint(root)
 	// __hold_till_enter__