Show warning about deprecated edit configs

We print this to the terminal after lazygit quits rather than showing it in a
panel at startup, so as to not annoy people too much. Hopefully it will still be
prominent enough this way.

pkg/gui/gui.go

@@ -495,6 +495,8 @@ func (gui *Gui) Run(startArgs appTypes.StartArgs) error {
 		return err
 	}
 
+	defer gui.checkForDeprecatedEditConfigs()
+
 	gui.g = g
 	defer gui.g.Close()
 
@@ -583,6 +585,37 @@ func (gui *Gui) RunAndHandleError(startArgs appTypes.StartArgs) error {
 	})
 }
 
+func (gui *Gui) checkForDeprecatedEditConfigs() {
+	osConfig := &gui.UserConfig.OS
+	deprecatedConfigs := []struct {
+		config  string
+		oldName string
+		newName string
+	}{
+		{osConfig.EditCommand, "EditCommand", "Edit"},
+		{osConfig.EditCommandTemplate, "EditCommandTemplate", "Edit,EditAtLine"},
+		{osConfig.OpenCommand, "OpenCommand", "Open"},
+		{osConfig.OpenLinkCommand, "OpenLinkCommand", "OpenLink"},
+	}
+	deprecatedConfigStrings := []string{}
+
+	for _, dc := range deprecatedConfigs {
+		if dc.config != "" {
+			deprecatedConfigStrings = append(deprecatedConfigStrings, fmt.Sprintf("   OS.%s -> OS.%s", dc.oldName, dc.newName))
+		}
+	}
+	if len(deprecatedConfigStrings) != 0 {
+		warningMessage := utils.ResolvePlaceholderString(
+			gui.c.Tr.DeprecatedEditConfigWarning,
+			map[string]string{
+				"configs": strings.Join(deprecatedConfigStrings, "\n"),
+			},
+		)
+
+		os.Stdout.Write([]byte(warningMessage))
+	}
+}
+
 // returns whether command exited without error or not
 func (gui *Gui) runSubprocessWithSuspenseAndRefresh(subprocess oscommands.ICmdObj) error {
 	_, err := gui.runSubprocessWithSuspense(subprocess)

pkg/i18n/english.go

@@ -155,6 +155,7 @@ type TranslationSet struct {
 	MergeToolTitle                      string
 	MergeToolPrompt                     string
 	IntroPopupMessage                   string
+	DeprecatedEditConfigWarning         string
 	GitconfigParseErr                   string
 	LcEditFile                          string
 	LcOpenFile                          string
@@ -659,6 +660,21 @@ Thanks for using lazygit! Seriously you rock. Three things to share with you:
     Or even just star the repo to share the love!
 `
 
+const englishDeprecatedEditConfigWarning = `
+### Deprecated config warning ###
+
+The following config settings are deprecated and will be removed in a future
+version:
+{{configs}}
+
+Please refer to
+
+  https://github.com/jesseduffield/lazygit/blob/master/docs/Config.md#configuring-file-editing
+
+for up-to-date information how to configure your editor.
+
+`
+
 // exporting this so we can use it in tests
 func EnglishTranslationSet() TranslationSet {
 	return TranslationSet{
@@ -805,6 +821,7 @@ func EnglishTranslationSet() TranslationSet {
 		MergeToolTitle:                      "Merge tool",
 		MergeToolPrompt:                     "Are you sure you want to open `git mergetool`?",
 		IntroPopupMessage:                   englishIntroPopupMessage,
+		DeprecatedEditConfigWarning:         englishDeprecatedEditConfigWarning,
 		GitconfigParseErr:                   `Gogit failed to parse your gitconfig file due to the presence of unquoted '\' characters. Removing these should fix the issue.`,
 		LcEditFile:                          `edit file`,
 		LcOpenFile:                          `open file`,