feat: add confirm prompt for custom keybindings

- Supports configuring a custom confirmation prompt via `config.yml` for
  custom keybindings. A new `CustomCommandPrompt.Body` field is
  used to store the immutable body text of the confirmation popup.
- Adds a sample 'confirm' prompt to the example `config.yml`.
- Updates the `Prompts` section of the documentation to include
  'confirm' prompt type and also describe which fields pertain to it
  (i.e. `initialValue`).

Closes: https://github.com/jesseduffield/lazygit/issues/1858

Signed-off-by: Michael Mead <mmead.developer@gmail.com>

docs/Custom_Command_Keybindings.md

@@ -49,6 +49,13 @@ customCommands:
         filter: '.*{{index .PromptResponses 0}}/(?P<branch>.*)'
         valueFormat: '{{ .branch }}'
         labelFormat: '{{ .branch | green }}'
+  - key: '<f1>'
+    command: 'git reset --soft {{.CheckedOutBranch.UpstreamRemote}}'
+    context: 'files'
+    prompts:
+      - type: 'confirm'
+        title: "Confirm:"
+        body: "Are you sure you want to reset HEAD to {{.CheckedOutBranch.UpstreamRemote}}?"
 ```
 
 Looking at the command assigned to the 'n' key, here's what the result looks like:
@@ -94,14 +101,15 @@ The permitted contexts are:
 
 The permitted prompt fields are:
 
-| _field_           | _description_                                                                    | _required_ |
+| _field_           | _description_                                                                                  | _required_ |
-| ------------      | -------------------------------------------------------------------------------- | ---------- |
+| ------------      | -----------------------------------------------------------------------------------------------| ---------- |
-| type              | one of 'input' or 'menu'                                                         | yes        |
+| type              | one of 'input', 'menu', or 'confirm'                                                           | yes        |
-| title             | the title to display in the popup panel                                          | no         |
+| title             | the title to display in the popup panel                                                        | no         |
-| initialValue      | (only applicable to 'input' prompts) the initial value to appear in the text box | no         |
+| initialValue      | (only applicable to 'input' prompts) the initial value to appear in the text box               | no         |
-| options           | (only applicable to 'menu' prompts) the options to display in the menu           | no         |
+| body              | (only applicable to 'confirm' prompts) the immutable body text to appear in the text box       | no         |
-| command           | (only applicable to 'menuFromCommand' prompts) the command to run to generate    | yes        |
+| options           | (only applicable to 'menu' prompts) the options to display in the menu                         | no         |
-|                   | menu options                                                                     |            |
+| command           | (only applicable to 'menuFromCommand' prompts) the command to run to generate                  | yes        |
+|                   | menu options                                                                                   |            |
 | filter            | (only applicable to 'menuFromCommand' prompts) the regexp to run specifying groups which are going to be kept from the command's output      | yes        |
 | valueFormat       | (only applicable to 'menuFromCommand' prompts) how to format matched groups from the filter to construct a menu item's value (What gets appended to prompt responses when the item is selected). You can use named groups, or `{{ .group_GROUPID }}`. PS: named groups keep first match only | yes        |
 | labelFormat       | (only applicable to 'menuFromCommand' prompts) how to format matched groups from the filter to construct the item's label (What's shown on screen). You can use named groups, or `{{ .group_GROUPID }}`. You can also color each match with `{{ .group_GROUPID \| colorname }}` (Color names from [here](https://github.com/jesseduffield/lazygit/blob/master/docs/Config.md)). If `labelFormat` is not specified, `valueFormat` is shown instead. PS: named groups keep first match only | no         |

pkg/config/user_config.go

@@ -313,12 +313,15 @@ type CustomCommand struct {
 }
 
 type CustomCommandPrompt struct {
-	Type  string `yaml:"type"` // one of 'input' and 'menu'
+	Type  string `yaml:"type"` // one of 'input', 'menu', or 'confirm'
 	Title string `yaml:"title"`
 
 	// this only apply to prompts
 	InitialValue string `yaml:"initialValue"`
 
+	// this only applies to confirm prompts
+	Body string `yaml:"body"`
+
 	// this only applies to menus
 	Options []CustomCommandMenuOption
 

pkg/gui/services/custom_commands/handler_creator.go

@@ -80,8 +80,12 @@ func (self *HandlerCreator) call(customCommand config.CustomCommand) func() erro
 				f = func() error {
 					return self.menuPromptFromCommand(resolvedPrompt, wrappedF)
 				}
+			case "confirm":
+				f = func() error {
+					return self.confirmPrompt(resolvedPrompt, g)
+				}
 			default:
-				return self.c.ErrorMsg("custom command prompt must have a type of 'input', 'menu' or 'menuFromCommand'")
+				return self.c.ErrorMsg("custom command prompt must have a type of 'input', 'menu', 'menuFromCommand', or 'confirm'")
 			}
 		}
 
@@ -112,6 +116,14 @@ func (self *HandlerCreator) menuPrompt(prompt *config.CustomCommandPrompt, wrapp
 	return self.c.Menu(types.CreateMenuOptions{Title: prompt.Title, Items: menuItems})
 }
 
+func (self *HandlerCreator) confirmPrompt(prompt *config.CustomCommandPrompt, handleConfirm func() error) error {
+	return self.c.Confirm(types.ConfirmOpts{
+		Title:         prompt.Title,
+		Prompt:        prompt.Body,
+		HandleConfirm: handleConfirm,
+	})
+}
+
 func (self *HandlerCreator) menuPromptFromCommand(prompt *config.CustomCommandPrompt, wrappedF func(string) error) error {
 	// Run and save output
 	message, err := self.git.Custom.RunWithOutput(prompt.Command)

pkg/gui/services/custom_commands/resolver.go

@@ -34,6 +34,11 @@ func (self *Resolver) resolvePrompt(
 		return nil, err
 	}
 
+	result.Body, err = resolveTemplate(prompt.Body)
+	if err != nil {
+		return nil, err
+	}
+
 	result.Command, err = resolveTemplate(prompt.Command)
 	if err != nil {
 		return nil, err