Don't allow empty input in most prompts (#5043)

Most of our prompts don't (shouldn't) allow empty input, but most
callers didn't check, and would run into cryptic errors when the user
pressed enter at an empty prompt (e.g. when creating a new branch). Now
we simply don't allow hitting enter in this case, and show an error
toast instead.

This behavior is opt-out, because there are a few cases where empty
input is supported (e.g. creating a stash).

pkg/gui/controllers/diffing_menu_action.go

@@ -2,7 +2,6 @@ package controllers
 
 import (
 	"fmt"
-	"strings"
 
 	"github.com/jesseduffield/lazygit/pkg/gui/modes/diffing"
 	"github.com/jesseduffield/lazygit/pkg/gui/types"
@@ -38,7 +37,7 @@ func (self *DiffingMenuAction) Call() error {
 					Title:               self.c.Tr.EnterRefName,
 					FindSuggestionsFunc: self.c.Helpers().Suggestions.GetRefsSuggestionsFunc(),
 					HandleConfirm: func(response string) error {
-						self.c.Modes().Diffing.Ref = strings.TrimSpace(response)
+						self.c.Modes().Diffing.Ref = response
 						self.c.Refresh(types.RefreshOptions{Mode: types.ASYNC})
 						return nil
 					},

pkg/gui/controllers/files_controller.go

@@ -1211,6 +1211,7 @@ func (self *FilesController) handleStashSave(stashFunc func(message string) erro
 			self.c.Refresh(types.RefreshOptions{Scope: []types.RefreshableView{types.STASH, types.FILES}})
 			return nil
 		},
+		AllowEmptyInput: true,
 	})
 
 	return nil

pkg/gui/controllers/filtering_menu_action.go

@@ -2,7 +2,6 @@ package controllers
 
 import (
 	"fmt"
-	"strings"
 
 	"github.com/jesseduffield/lazygit/pkg/gui/controllers/helpers"
 	"github.com/jesseduffield/lazygit/pkg/gui/types"
@@ -66,7 +65,7 @@ func (self *FilteringMenuAction) Call() error {
 				FindSuggestionsFunc: self.c.Helpers().Suggestions.GetFilePathSuggestionsFunc(),
 				Title:               self.c.Tr.EnterFileName,
 				HandleConfirm: func(response string) error {
-					return self.setFilteringPath(strings.TrimSpace(response))
+					return self.setFilteringPath(response)
 				},
 			})
 
@@ -82,7 +81,7 @@ func (self *FilteringMenuAction) Call() error {
 				FindSuggestionsFunc: self.c.Helpers().Suggestions.GetAuthorsSuggestionsFunc(),
 				Title:               self.c.Tr.EnterAuthor,
 				HandleConfirm: func(response string) error {
-					return self.setFilteringAuthor(strings.TrimSpace(response))
+					return self.setFilteringAuthor(response)
 				},
 			})
 

pkg/gui/controllers/helpers/confirmation_helper.go

@@ -24,16 +24,7 @@ func NewConfirmationHelper(c *HelperCommon) *ConfirmationHelper {
 // This file is for the rendering of confirmation panels along with setting and handling associated
 // keybindings.
 
-func (self *ConfirmationHelper) wrappedConfirmationFunction(cancel goContext.CancelFunc, function func() error) func() error {
+func (self *ConfirmationHelper) closeAndCallConfirmationFunction(cancel goContext.CancelFunc, function func() error) error {
-	return func() error {
-		if self.c.GocuiGui().IsPasting {
-			// The user is pasting multi-line text into a prompt; we don't want to handle the
-			// line feeds as "confirm" keybindings. Simply ignoring them is the best we can do; this
-			// will cause the entire pasted text to appear as a single line in the prompt. Hopefully
-			// the user knows that ctrl-u allows them to delete it again...
-			return nil
-		}
-
 	cancel()
 
 	self.c.Context().Pop()
@@ -46,13 +37,44 @@ func (self *ConfirmationHelper) wrappedConfirmationFunction(cancel goContext.Can
 
 	return nil
 }
+
+func (self *ConfirmationHelper) wrappedConfirmationFunction(cancel goContext.CancelFunc, function func() error) func() error {
+	return func() error {
+		return self.closeAndCallConfirmationFunction(cancel, function)
+	}
 }
 
-func (self *ConfirmationHelper) wrappedPromptConfirmationFunction(cancel goContext.CancelFunc, function func(string) error, getResponse func() string) func() error {
+func (self *ConfirmationHelper) wrappedPromptConfirmationFunction(
-	return self.wrappedConfirmationFunction(cancel, func() error {
+	cancel goContext.CancelFunc,
-		return function(getResponse())
+	function func(string) error,
+	getResponse func() string,
+	allowEmptyInput bool,
+	preserveWhitespace bool,
+) func() error {
+	return func() error {
+		if self.c.GocuiGui().IsPasting {
+			// The user is pasting multi-line text into a prompt; we don't want to handle the
+			// line feeds as "confirm" keybindings. Simply ignoring them is the best we can do; this
+			// will cause the entire pasted text to appear as a single line in the prompt. Hopefully
+			// the user knows that ctrl-u allows them to delete it again...
+			return nil
+		}
+
+		response := getResponse()
+		if !preserveWhitespace {
+			response = strings.TrimSpace(response)
+		}
+
+		if response == "" && !allowEmptyInput {
+			self.c.ErrorToast(self.c.Tr.PromptInputCannotBeEmptyToast)
+			return nil
+		}
+
+		return self.closeAndCallConfirmationFunction(cancel, func() error {
+			return function(response)
 		})
 	}
+}
 
 func (self *ConfirmationHelper) DeactivateConfirmation() {
 	self.c.Mutexes().PopupMutex.Lock()
@@ -229,12 +251,15 @@ func (self *ConfirmationHelper) setConfirmationKeyBindings(cancel goContext.Canc
 
 func (self *ConfirmationHelper) setPromptKeyBindings(cancel goContext.CancelFunc, opts types.CreatePopupPanelOpts) {
 	onConfirm := self.wrappedPromptConfirmationFunction(cancel, opts.HandleConfirmPrompt,
-		func() string { return self.c.Views().Prompt.TextArea.GetContent() })
+		func() string { return self.c.Views().Prompt.TextArea.GetContent() },
+		opts.AllowEmptyInput, opts.PreserveWhitespace)
 
 	onSuggestionConfirm := self.wrappedPromptConfirmationFunction(
 		cancel,
 		opts.HandleConfirmPrompt,
 		self.getSelectedSuggestionValue,
+		opts.AllowEmptyInput,
+		opts.PreserveWhitespace,
 	)
 
 	onClose := self.wrappedConfirmationFunction(cancel, opts.HandleClose)

pkg/gui/controllers/helpers/credentials_helper.go

@@ -41,6 +41,7 @@ func (self *CredentialsHelper) PromptUserForCredential(passOrUname oscommands.Cr
 
 				return nil
 			},
+			AllowEmptyInput: true,
 		})
 
 		return nil

pkg/gui/controllers/helpers/worktree_helper.go

@@ -130,23 +130,21 @@ func (self *WorktreeHelper) NewWorktreeCheckout(base string, canCheckoutBase boo
 
 						return f()
 					},
+					AllowEmptyInput: true,
 				})
 
 				return nil
 			}
 
-			// prompt for the new branch name where a blank means we just check out the branch
+			// prompt for the new branch name
 			self.c.Prompt(types.PromptOpts{
 				Title: self.c.Tr.NewBranchName,
 				HandleConfirm: func(branchName string) error {
-					if branchName == "" {
-						return errors.New(self.c.Tr.BranchNameCannotBeBlank)
-					}
-
 					opts.Branch = branchName
 
 					return f()
 				},
+				AllowEmptyInput: false,
 			})
 
 			return nil

pkg/gui/controllers/shell_command_action.go

@@ -19,6 +19,7 @@ func (self *ShellCommandAction) Call() error {
 		Title:               self.c.Tr.ShellCommand,
 		FindSuggestionsFunc: self.GetShellCommandsHistorySuggestionsFunc(),
 		AllowEditSuggestion: true,
+		PreserveWhitespace:  true,
 		HandleConfirm: func(command string) error {
 			if self.shouldSaveCommand(command) {
 				self.c.GetAppState().ShellCommandsHistory = utils.Limit(

pkg/gui/controllers/stash_controller.go

@@ -209,6 +209,7 @@ func (self *StashController) handleRenameStashEntry(stashEntry *models.StashEntr
 			self.c.Refresh(types.RefreshOptions{Scope: []types.RefreshableView{types.STASH}})
 			return nil
 		},
+		AllowEmptyInput: true,
 	})
 
 	return nil

pkg/gui/popup/popup_handler.go

@@ -139,6 +139,8 @@ func (self *PopupHandler) Prompt(opts types.PromptOpts) {
 		HandleDeleteSuggestion: opts.HandleDeleteSuggestion,
 		FindSuggestionsFunc:    opts.FindSuggestionsFunc,
 		AllowEditSuggestion:    opts.AllowEditSuggestion,
+		AllowEmptyInput:        opts.AllowEmptyInput,
+		PreserveWhitespace:     opts.PreserveWhitespace,
 		Mask:                   opts.Mask,
 	})
 }

pkg/gui/services/custom_commands/handler_creator.go

@@ -125,6 +125,8 @@ func (self *HandlerCreator) inputPrompt(prompt *config.CustomCommandPrompt, wrap
 		HandleConfirm: func(str string) error {
 			return wrappedF(str)
 		},
+		AllowEmptyInput:    true,
+		PreserveWhitespace: true,
 	})
 
 	return nil

pkg/gui/types/common.go

@@ -172,6 +172,8 @@ type CreatePopupPanelOpts struct {
 	FindSuggestionsFunc func(string) []*Suggestion
 	Mask                bool
 	AllowEditSuggestion bool
+	AllowEmptyInput     bool
+	PreserveWhitespace  bool
 }
 
 type ConfirmOpts struct {
@@ -190,6 +192,8 @@ type PromptOpts struct {
 	FindSuggestionsFunc func(string) []*Suggestion
 	HandleConfirm       func(string) error
 	AllowEditSuggestion bool
+	AllowEmptyInput     bool
+	PreserveWhitespace  bool
 	// CAPTURE THIS
 	HandleClose            func() error
 	HandleDeleteSuggestion func(int) error

pkg/i18n/english.go

@@ -618,6 +618,7 @@ type TranslationSet struct {
 	MustStashTitle                        string
 	ConfirmationTitle                     string
 	PromptTitle                           string
+	PromptInputCannotBeEmptyToast         string
 	PrevPage                              string
 	NextPage                              string
 	GotoTop                               string
@@ -861,7 +862,6 @@ type TranslationSet struct {
 	NewWorktreePath                          string
 	NewWorktreeBase                          string
 	RemoveWorktreeTooltip                    string
-	BranchNameCannotBeBlank                  string
 	NewBranchName                            string
 	NewBranchNameLeaveBlank                  string
 	ViewWorktreeOptions                      string
@@ -1713,6 +1713,7 @@ func EnglishTranslationSet() *TranslationSet {
 		MustStashTitle:                   "Must stash",
 		ConfirmationTitle:                "Confirmation panel",
 		PromptTitle:                      "Input prompt",
+		PromptInputCannotBeEmptyToast:    "Empty input is not allowed",
 		PrevPage:                         "Previous page",
 		NextPage:                         "Next page",
 		GotoTop:                          "Scroll to top",
@@ -1954,7 +1955,6 @@ func EnglishTranslationSet() *TranslationSet {
 		NewWorktreePath:                          "New worktree path",
 		NewWorktreeBase:                          "New worktree base ref",
 		RemoveWorktreeTooltip:                    "Remove the selected worktree. This will both delete the worktree's directory, as well as metadata about the worktree in the .git directory.",
-		BranchNameCannotBeBlank:                  "Branch name cannot be blank",
 		NewBranchName:                            "New branch name",
 		NewBranchNameLeaveBlank:                  "New branch name (leave blank to checkout {{.default}})",
 		ViewWorktreeOptions:                      "View worktree options",