Add command "View divergence from base branch"

pkg/gui/controllers/branches_controller.go

@@ -205,6 +205,40 @@ func (self *BranchesController) viewUpstreamOptions(selectedBranch *models.Branc
 		},
 	}
 
+	var disabledReason *types.DisabledReason
+	baseBranch, err := self.c.Git().Loaders.BranchLoader.GetBaseBranch(selectedBranch, self.c.Model().MainBranches)
+	if err != nil {
+		return err
+	}
+	if baseBranch == "" {
+		baseBranch = self.c.Tr.CouldNotDetermineBaseBranch
+		disabledReason = &types.DisabledReason{Text: self.c.Tr.CouldNotDetermineBaseBranch}
+	}
+	shortBaseBranchName := helpers.ShortBranchName(baseBranch)
+	label := utils.ResolvePlaceholderString(
+		self.c.Tr.ViewDivergenceFromBaseBranch,
+		map[string]string{"baseBranch": shortBaseBranchName},
+	)
+	viewDivergenceFromBaseBranchItem := &types.MenuItem{
+		LabelColumns: []string{label},
+		Key:          'b',
+		OnPress: func() error {
+			branch := self.context().GetSelected()
+			if branch == nil {
+				return nil
+			}
+
+			return self.c.Helpers().SubCommits.ViewSubCommits(helpers.ViewSubCommitsOpts{
+				Ref:                     branch,
+				TitleRef:                fmt.Sprintf("%s <-> %s", branch.RefName(), shortBaseBranchName),
+				RefToShowDivergenceFrom: baseBranch,
+				Context:                 self.context(),
+				ShowBranchHeads:         false,
+			})
+		},
+		DisabledReason: disabledReason,
+	}
+
 	unsetUpstreamItem := &types.MenuItem{
 		LabelColumns: []string{self.c.Tr.UnsetUpstream},
 		OnPress: func() error {
@@ -312,6 +346,7 @@ func (self *BranchesController) viewUpstreamOptions(selectedBranch *models.Branc
 
 	options := []*types.MenuItem{
 		viewDivergenceItem,
+		viewDivergenceFromBaseBranchItem,
 		unsetUpstreamItem,
 		setUpstreamItem,
 		upstreamResetItem,

pkg/gui/controllers/helpers/branches_helper.go

@@ -1,6 +1,8 @@
 package helpers
 
 import (
+	"strings"
+
 	"github.com/jesseduffield/gocui"
 	"github.com/jesseduffield/lazygit/pkg/gui/types"
 	"github.com/jesseduffield/lazygit/pkg/utils"
@@ -44,3 +46,7 @@ func (self *BranchesHelper) ConfirmDeleteRemote(remoteName string, branchName st
 		},
 	})
 }
+
+func ShortBranchName(fullBranchName string) string {
+	return strings.TrimPrefix(strings.TrimPrefix(fullBranchName, "refs/heads/"), "refs/remotes/")
+}

pkg/i18n/english.go

@@ -468,6 +468,8 @@ type TranslationSet struct {
 	SetUpstream                           string
 	UnsetUpstream                         string
 	ViewDivergenceFromUpstream            string
+	ViewDivergenceFromBaseBranch          string
+	CouldNotDetermineBaseBranch           string
 	DivergenceSectionHeaderLocal          string
 	DivergenceSectionHeaderRemote         string
 	ViewUpstreamResetOptions              string
@@ -1434,6 +1436,8 @@ func EnglishTranslationSet() TranslationSet {
 		SetUpstream:                          "Set upstream of selected branch",
 		UnsetUpstream:                        "Unset upstream of selected branch",
 		ViewDivergenceFromUpstream:           "View divergence from upstream",
+		ViewDivergenceFromBaseBranch:         "View divergence from base branch ({{.baseBranch}})",
+		CouldNotDetermineBaseBranch:          "Couldn't determine base branch",
 		DivergenceSectionHeaderLocal:         "Local",
 		DivergenceSectionHeaderRemote:        "Remote",
 		ViewUpstreamResetOptions:             "Reset checked-out branch onto {{.upstream}}",

pkg/integration/tests/branch/show_divergence_from_base_branch.go

@@ -0,0 +1,47 @@
+package branch
+
+import (
+	"github.com/jesseduffield/lazygit/pkg/config"
+	. "github.com/jesseduffield/lazygit/pkg/integration/components"
+)
+
+var ShowDivergenceFromBaseBranch = NewIntegrationTest(NewIntegrationTestArgs{
+	Description:  "Show divergence from base branch",
+	ExtraCmdArgs: []string{},
+	Skip:         false,
+	SetupConfig: func(config *config.AppConfig) {
+		config.UserConfig.Gui.ShowDivergenceFromBaseBranch = "arrowAndNumber"
+	},
+	SetupRepo: func(shell *Shell) {
+		shell.
+			EmptyCommit("master 1").
+			EmptyCommit("master 2").
+			EmptyCommit("master 3").
+			NewBranchFrom("feature", "master^").
+			EmptyCommit("feature 1").
+			EmptyCommit("feature 2")
+	},
+	Run: func(t *TestDriver, keys config.KeybindingConfig) {
+		t.Views().Branches().
+			Focus().
+			Lines(
+				Contains("feature ↓1").IsSelected(),
+				Contains("master"),
+			).
+			Press(keys.Branches.SetUpstream)
+
+		t.ExpectPopup().Menu().Title(Contains("Upstream")).
+			Select(Contains("View divergence from base branch (master)")).Confirm()
+
+		t.Views().SubCommits().
+			IsFocused().
+			Title(Contains("Commits (feature <-> master)")).
+			Lines(
+				DoesNotContainAnyOf("↓", "↑").Contains("--- Remote ---"),
+				Contains("↓").Contains("master 3"),
+				DoesNotContainAnyOf("↓", "↑").Contains("--- Local ---"),
+				Contains("↑").Contains("feature 2"),
+				Contains("↑").Contains("feature 1"),
+			)
+	},
+})

pkg/integration/tests/test_list.go

@@ -56,6 +56,7 @@ var tests = []*components.IntegrationTest{
 	branch.Reset,
 	branch.ResetToUpstream,
 	branch.SetUpstream,
+	branch.ShowDivergenceFromBaseBranch,
 	branch.ShowDivergenceFromUpstream,
 	branch.SortLocalBranches,
 	branch.SortRemoteBranches,