1 files changed, 287 insertions, 0 deletions
diff --git a/pkg/commands/rebasing.go b/pkg/commands/rebasing.go
new file mode 100644
index 000000000..30e87c5dc
--- /dev/null
+++ b/pkg/commands/rebasing.go
@@ -0,0 +1,287 @@
+package commands
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+
+	"github.com/go-errors/errors"
+	"github.com/jesseduffield/lazygit/pkg/models"
+	"github.com/mgutz/str"
+)
+
+func (c *GitCommand) RewordCommit(commits []*models.Commit, index int) (*exec.Cmd, error) {
+	todo, sha, err := c.GenerateGenericRebaseTodo(commits, index, "reword")
+	if err != nil {
+		return nil, err
+	}
+
+	return c.PrepareInteractiveRebaseCommand(sha, todo, false)
+}
+
+func (c *GitCommand) MoveCommitDown(commits []*models.Commit, index int) error {
+	// we must ensure that we have at least two commits after the selected one
+	if len(commits) <= index+2 {
+		// assuming they aren't picking the bottom commit
+		return errors.New(c.Tr.SLocalize("NoRoom"))
+	}
+
+	todo := ""
+	orderedCommits := append(commits[0:index], commits[index+1], commits[index])
+	for _, commit := range orderedCommits {
+		todo = "pick " + commit.Sha + " " + commit.Name + "\n" + todo
+	}
+
+	cmd, err := c.PrepareInteractiveRebaseCommand(commits[index+2].Sha, todo, true)
+	if err != nil {
+		return err
+	}
+
+	return c.OSCommand.RunPreparedCommand(cmd)
+}
+
+func (c *GitCommand) InteractiveRebase(commits []*models.Commit, index int, action string) error {
+	todo, sha, err := c.GenerateGenericRebaseTodo(commits, index, action)
+	if err != nil {
+		return err
+	}
+
+	cmd, err := c.PrepareInteractiveRebaseCommand(sha, todo, true)
+	if err != nil {
+		return err
+	}
+
+	return c.OSCommand.RunPreparedCommand(cmd)
+}
+
+// PrepareInteractiveRebaseCommand returns the cmd for an interactive rebase
+// we tell git to run lazygit to edit the todo list, and we pass the client
+// lazygit a todo string to write to the todo file
+func (c *GitCommand) PrepareInteractiveRebaseCommand(baseSha string, todo string, overrideEditor bool) (*exec.Cmd, error) {
+	ex := c.OSCommand.GetLazygitPath()
+
+	debug := "FALSE"
+	if c.OSCommand.Config.GetDebug() {
+		debug = "TRUE"
+	}
+
+	cmdStr := fmt.Sprintf("git rebase --interactive --autostash --keep-empty %s", baseSha)
+	c.Log.WithField("command", cmdStr).Info("RunCommand")
+	splitCmd := str.ToArgv(cmdStr)
+
+	cmd := c.OSCommand.Command(splitCmd[0], splitCmd[1:]...)
+
+	gitSequenceEditor := ex
+	if todo == "" {
+		gitSequenceEditor = "true"
+	}
+
+	cmd.Env = os.Environ()
+	cmd.Env = append(
+		cmd.Env,
+		"LAZYGIT_CLIENT_COMMAND=INTERACTIVE_REBASE",
+		"LAZYGIT_REBASE_TODO="+todo,
+		"DEBUG="+debug,
+		"LANG=en_US.UTF-8",   // Force using EN as language
+		"LC_ALL=en_US.UTF-8", // Force using EN as language
+		"GIT_SEQUENCE_EDITOR="+gitSequenceEditor,
+	)
+
+	if overrideEditor {
+		cmd.Env = append(cmd.Env, "GIT_EDITOR="+ex)
+	}
+
+	return cmd, nil
+}
+
+func (c *GitCommand) GenerateGenericRebaseTodo(commits []*models.Commit, actionIndex int, action string) (string, string, error) {
+	baseIndex := actionIndex + 1
+
+	if len(commits) <= baseIndex {
+		return "", "", errors.New(c.Tr.SLocalize("CannotRebaseOntoFirstCommit"))
+	}
+
+	if action == "squash" || action == "fixup" {
+		baseIndex++
+
+		if len(commits) <= baseIndex {
+			return "", "", errors.New(c.Tr.SLocalize("CannotSquashOntoSecondCommit"))
+		}
+	}
+
+	todo := ""
+	for i, commit := range commits[0:baseIndex] {
+		var commitAction string
+		if i == actionIndex {
+			commitAction = action
+		} else if commit.IsMerge {
+			// your typical interactive rebase will actually drop merge commits by default. Damn git CLI, you scary!
+			// doing this means we don't need to worry about rebasing over merges which always causes problems.
+			// you typically shouldn't be doing rebases that pass over merge commits anyway.
+			commitAction = "drop"
+		} else {
+			commitAction = "pick"
+		}
+		todo = commitAction + " " + commit.Sha + " " + commit.Name + "\n" + todo
+	}
+
+	return todo, commits[baseIndex].Sha, nil
+}
+
+// AmendTo amends the given commit with whatever files are staged
+func (c *GitCommand) AmendTo(sha string) error {
+	if err := c.CreateFixupCommit(sha); err != nil {
+		return err
+	}
+
+	return c.SquashAllAboveFixupCommits(sha)
+}
+
+// EditRebaseTodo sets the action at a given index in the git-rebase-todo file
+func (c *GitCommand) EditRebaseTodo(index int, action string) error {
+	fileName := filepath.Join(c.DotGitDir, "rebase-merge/git-rebase-todo")
+	bytes, err := ioutil.ReadFile(fileName)
+	if err != nil {
+		return err
+	}
+
+	content := strings.Split(string(bytes), "\n")
+	commitCount := c.getTodoCommitCount(content)
+
+	// we have the most recent commit at the bottom whereas the todo file has
+	// it at the bottom, so we need to subtract our index from the commit count
+	contentIndex := commitCount - 1 - index
+	splitLine := strings.Split(content[contentIndex], " ")
+	content[contentIndex] = action + " " + strings.Join(splitLine[1:], " ")
+	result := strings.Join(content, "\n")
+
+	return ioutil.WriteFile(fileName, []byte(result), 0644)
+}
+
+func (c *GitCommand) getTodoCommitCount(content []string) int {
+	// count lines that are not blank and are not comments
+	commitCount := 0
+	for _, line := range content {
+		if line != "" && !strings.HasPrefix(line, "#") {
+			commitCount++
+		}
+	}
+	return commitCount
+}
+
+// MoveTodoDown moves a rebase todo item down by one position
+func (c *GitCommand) MoveTodoDown(index int) error {
+	fileName := filepath.Join(c.DotGitDir, "rebase-merge/git-rebase-todo")
+	bytes, err := ioutil.ReadFile(fileName)
+	if err != nil {
+		return err
+	}
+
+	content := strings.Split(string(bytes), "\n")
+	commitCount := c.getTodoCommitCount(content)
+	contentIndex := commitCount - 1 - index
+
+	rearrangedContent := append(content[0:contentIndex-1], content[contentIndex], content[contentIndex-1])
+	rearrangedContent = append(rearrangedContent, content[contentIndex+1:]...)
+	result := strings.Join(rearrangedContent, "\n")
+
+	return ioutil.WriteFile(fileName, []byte(result), 0644)
+}
+
+// SquashAllAboveFixupCommits squashes all fixup! commits above the given one
+func (c *GitCommand) SquashAllAboveFixupCommits(sha string) error {
+	return c.runSkipEditorCommand(
+		fmt.Sprintf(
+			"git rebase --interactive --autostash --autosquash %s^",
+			sha,
+		),
+	)
+}
+
+// BeginInteractiveRebaseForCommit starts an interactive rebase to edit the current
+// commit and pick all others. After this you'll want to call `c.GenericMergeOrRebaseAction("rebase", "continue")`
+func (c *GitCommand) BeginInteractiveRebaseForCommit(commits []*models.Commit, commitIndex int) error {
+	if len(commits)-1 < commitIndex {
+		return errors.New("index outside of range of commits")
+	}
+
+	// we can make this GPG thing possible it just means we need to do this in two parts:
+	// one where we handle the possibility of a credential request, and the other
+	// where we continue the rebase
+	if c.usingGpg() {
+		return errors.New(c.Tr.SLocalize("DisabledForGPG"))
+	}
+
+	todo, sha, err := c.GenerateGenericRebaseTodo(commits, commitIndex, "edit")
+	if err != nil {
+		return err
+	}
+
+	cmd, err := c.PrepareInteractiveRebaseCommand(sha, todo, true)
+	if err != nil {
+		return err
+	}
+
+	if err := c.OSCommand.RunPreparedCommand(cmd); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// RebaseBranch interactive rebases onto a branch
+func (c *GitCommand) RebaseBranch(branchName string) error {
+	cmd, err := c.PrepareInteractiveRebaseCommand(branchName, "", false)
+	if err != nil {
+		return err
+	}
+
+	return c.OSCommand.RunPreparedCommand(cmd)
+}
+
+// GenericMerge takes a commandType of "merge" or "rebase" and a command of "abort", "skip" or "continue"
+// By default we skip the editor in the case where a commit will be made
+func (c *GitCommand) GenericMergeOrRebaseAction(commandType string, command string) error {
+	err := c.runSkipEditorCommand(
+		fmt.Sprintf(
+			"git %s --%s",
+			commandType,
+			command,
+		),
+	)
+	if err != nil {
+		if !strings.Contains(err.Error(), "no rebase in progress") {
+			return err
+		}
+		c.Log.Warn(err)
+	}
+
+	// sometimes we need to do a sequence of things in a rebase but the user needs to
+	// fix merge conflicts along the way. When this happens we queue up the next step
+	// so that after the next successful rebase continue we can continue from where we left off
+	if commandType == "rebase" && command == "continue" && c.onSuccessfulContinue != nil {
+		f := c.onSuccessfulContinue
+		c.onSuccessfulContinue = nil
+		return f()
+	}
+	if command == "abort" {
+		c.onSuccessfulContinue = nil
+	}
+	return nil
+}
+
+func (c *GitCommand) runSkipEditorCommand(command string) error {
+	cmd := c.OSCommand.ExecutableFromString(command)
+	lazyGitPath := c.OSCommand.GetLazygitPath()
+	cmd.Env = append(
+		cmd.Env,
+		"LAZYGIT_CLIENT_COMMAND=EXIT_IMMEDIATELY",
+		"GIT_EDITOR="+lazyGitPath,
+		"EDITOR="+lazyGitPath,
+		"VISUAL="+lazyGitPath,
+	)
+	return c.OSCommand.RunExecutable(cmd)
+}