Ask to auto-stage unstaged files when continuing a rebase after resolving conflicts (#3879)

- **PR Description**

When lazygit sees that all conflicts were resolved, it auto-stages all
previously conflicted files and asks to continue the rebase. (There is
[a PR](https://github.com/jesseduffield/lazygit/pull/3870) open to make
this optional.)

It is a common situation for this popup to be opened in the background,
while the user is still busy fixing build errors in their editor. In
this case, coming back to lazygit and confirming the continue prompt
would result in an error because not all files are staged.

Improve this by opening another popup in this case, asking to stage the
newly modified files too and continue.

See
https://github.com/jesseduffield/lazygit/issues/3111#issuecomment-1801751982
and the following discussion further down in that issue.

pkg/gui/controllers/helpers/merge_and_rebase_helper.go

@@ -247,6 +247,36 @@ func (self *MergeAndRebaseHelper) PromptToContinueRebase() error {
 		Title:  self.c.Tr.Continue,
 		Prompt: self.c.Tr.ConflictsResolved,
 		HandleConfirm: func() error {
+			// By the time we get here, we might have unstaged changes again,
+			// e.g. if the user had to fix build errors after resolving the
+			// conflicts, but after lazygit opened the prompt already. Ask again
+			// to auto-stage these.
+
+			// Need to refresh the files to be really sure if this is the case.
+			// We would otherwise be relying on lazygit's auto-refresh on focus,
+			// but this is not supported by all terminals or on all platforms.
+			if err := self.c.Refresh(types.RefreshOptions{
+				Mode: types.SYNC, Scope: []types.RefreshableView{types.FILES},
+			}); err != nil {
+				return err
+			}
+
+			root := self.c.Contexts().Files.FileTreeViewModel.GetRoot()
+			if root.GetHasUnstagedChanges() {
+				return self.c.Confirm(types.ConfirmOpts{
+					Title:  self.c.Tr.Continue,
+					Prompt: self.c.Tr.UnstagedFilesAfterConflictsResolved,
+					HandleConfirm: func() error {
+						self.c.LogAction(self.c.Tr.Actions.StageAllFiles)
+						if err := self.c.Git().WorkingTree.StageAll(); err != nil {
+							return err
+						}
+
+						return self.genericMergeCommand(REBASE_OPTION_CONTINUE)
+					},
+				})
+			}
+
 			return self.genericMergeCommand(REBASE_OPTION_CONTINUE)
 		},
 	})

pkg/i18n/english.go

@@ -296,6 +296,7 @@ type TranslationSet struct {
 	ReflogCommitsTitle                    string
 	ConflictsResolved                     string
 	Continue                              string
+	UnstagedFilesAfterConflictsResolved   string
 	RebasingTitle                         string
 	RebasingFromBaseCommitTitle           string
 	SimpleRebase                          string
@@ -1278,6 +1279,7 @@ func EnglishTranslationSet() *TranslationSet {
 		GlobalTitle:                          "Global keybindings",
 		ConflictsResolved:                    "All merge conflicts resolved. Continue?",
 		Continue:                             "Continue",
+		UnstagedFilesAfterConflictsResolved:  "Files have been modified since conflicts were resolved. Auto-stage them and continue?",
 		Keybindings:                          "Keybindings",
 		KeybindingsMenuSectionLocal:          "Local",
 		KeybindingsMenuSectionGlobal:         "Global",

pkg/integration/tests/branch/rebase_conflicts_fix_build_errors.go

@@ -0,0 +1,76 @@
+package branch
+
+import (
+	"github.com/jesseduffield/lazygit/pkg/config"
+	. "github.com/jesseduffield/lazygit/pkg/integration/components"
+	"github.com/jesseduffield/lazygit/pkg/integration/tests/shared"
+)
+
+var RebaseConflictsFixBuildErrors = NewIntegrationTest(NewIntegrationTestArgs{
+	Description:  "Rebase onto another branch, deal with the conflicts. While continue prompt is showing, fix build errors; get another prompt when continuing.",
+	ExtraCmdArgs: []string{},
+	Skip:         false,
+	SetupConfig:  func(config *config.AppConfig) {},
+	SetupRepo: func(shell *Shell) {
+		shared.MergeConflictsSetup(shell)
+	},
+	Run: func(t *TestDriver, keys config.KeybindingConfig) {
+		t.Views().Commits().TopLines(
+			Contains("first change"),
+			Contains("original"),
+		)
+
+		t.Views().Branches().
+			Focus().
+			Lines(
+				Contains("first-change-branch"),
+				Contains("second-change-branch"),
+				Contains("original-branch"),
+			).
+			SelectNextItem().
+			Press(keys.Branches.RebaseBranch)
+
+		t.ExpectPopup().Menu().
+			Title(Equals("Rebase 'first-change-branch'")).
+			Select(Contains("Simple rebase")).
+			Confirm()
+
+		t.Common().AcknowledgeConflicts()
+
+		t.Views().Files().
+			IsFocused().
+			SelectedLine(Contains("file")).
+			PressEnter()
+
+		t.Views().MergeConflicts().
+			IsFocused().
+			SelectNextItem().
+			PressPrimaryAction()
+
+		t.Views().Information().Content(Contains("Rebasing"))
+
+		popup := t.ExpectPopup().Confirmation().
+			Title(Equals("Continue")).
+			Content(Contains("All merge conflicts resolved. Continue?"))
+
+		// While the popup is showing, fix some build errors
+		t.Shell().UpdateFile("file", "make it compile again")
+
+		// Continue
+		popup.Confirm()
+
+		t.ExpectPopup().Confirmation().
+			Title(Equals("Continue")).
+			Content(Contains("Files have been modified since conflicts were resolved. Auto-stage them and continue?")).
+			Confirm()
+
+		t.Views().Information().Content(DoesNotContain("Rebasing"))
+
+		t.Views().Commits().TopLines(
+			Contains("first change"),
+			Contains("second-change-branch unrelated change"),
+			Contains("second change"),
+			Contains("original"),
+		)
+	},
+})

pkg/integration/tests/file/discard_all_dir_changes.go

@@ -94,6 +94,15 @@ var DiscardAllDirChanges = NewIntegrationTest(NewIntegrationTestArgs{
 			}).
 			Tap(func() {
 				t.Common().ContinueOnConflictsResolved()
+				t.ExpectPopup().Confirmation().
+					Title(Equals("Continue")).
+					Content(Contains("Files have been modified since conflicts were resolved. Auto-stage them and continue?")).
+					Cancel()
+				t.GlobalPress(keys.Universal.CreateRebaseOptionsMenu)
+				t.ExpectPopup().Menu().
+					Title(Equals("Merge options")).
+					Select(Contains("continue")).
+					Confirm()
 			}).
 			Lines(
 				Contains("dir").IsSelected(),

pkg/integration/tests/test_list.go

@@ -51,6 +51,7 @@ var tests = []*components.IntegrationTest{
 	branch.RebaseAbortOnConflict,
 	branch.RebaseAndDrop,
 	branch.RebaseCancelOnConflict,
+	branch.RebaseConflictsFixBuildErrors,
 	branch.RebaseCopiedBranch,
 	branch.RebaseDoesNotAutosquash,
 	branch.RebaseFromMarkedBase,