Add option to update pull request by `rebase` (#16125)

* add option to update pull request by `rebase`

Signed-off-by: a1012112796 <1012112796@qq.com>

2 files changed, 56 insertions, 16 deletions

diff --git a/services/pull/merge.go b/services/pull/merge.go
index 7e6a214b87..ef797e1ca4 100644
--- a/services/pull/merge.go
+++ b/services/pull/merge.go
@@ -253,6 +253,8 @@ func rawMerge(pr *models.PullRequest, doer *models.User, mergeStyle models.Merge
 		}
 	case models.MergeStyleRebase:
 		fallthrough
+	case models.MergeStyleRebaseUpdate:
+		fallthrough
 	case models.MergeStyleRebaseMerge:
 		// Checkout head branch
 		if err := git.NewCommand("checkout", "-b", stagingBranch, trackingBranch).RunInDirPipeline(tmpBasePath, &outbuf, &errbuf); err != nil {
@@ -305,6 +307,11 @@ func rawMerge(pr *models.PullRequest, doer *models.User, mergeStyle models.Merge
 		outbuf.Reset()
 		errbuf.Reset()
 
+		// not need merge, just update by rebase. so skip
+		if mergeStyle == models.MergeStyleRebaseUpdate {
+			break
+		}
+
 		// Checkout base branch again
 		if err := git.NewCommand("checkout", baseBranch).RunInDirPipeline(tmpBasePath, &outbuf, &errbuf); err != nil {
 			log.Error("git checkout base prior to merge post staging rebase [%s:%s -> %s:%s]: %v\n%s\n%s", pr.HeadRepo.FullName(), pr.HeadBranch, pr.BaseRepo.FullName(), pr.BaseBranch, err, outbuf.String(), errbuf.String())
@@ -410,8 +417,16 @@ func rawMerge(pr *models.PullRequest, doer *models.User, mergeStyle models.Merge
 		pr.ID,
 	)
 
+	var pushCmd *git.Command
+	if mergeStyle == models.MergeStyleRebaseUpdate {
+		// force push the rebase result to head brach
+		pushCmd = git.NewCommand("push", "-f", "head_repo", stagingBranch+":refs/heads/"+pr.HeadBranch)
+	} else {
+		pushCmd = git.NewCommand("push", "origin", baseBranch+":refs/heads/"+pr.BaseBranch)
+	}
+
 	// Push back to upstream.
-	if err := git.NewCommand("push", "origin", baseBranch+":refs/heads/"+pr.BaseBranch).RunInDirTimeoutEnvPipeline(env, -1, tmpBasePath, &outbuf, &errbuf); err != nil {
+	if err := pushCmd.RunInDirTimeoutEnvPipeline(env, -1, tmpBasePath, &outbuf, &errbuf); err != nil {
 		if strings.Contains(errbuf.String(), "non-fast-forward") {
 			return "", &git.ErrPushOutOfDate{
 				StdOut: outbuf.String(),
diff --git a/services/pull/update.go b/services/pull/update.go
index c2c13845e3..4b4e67797e 100644
--- a/services/pull/update.go
+++ b/services/pull/update.go
@@ -13,13 +13,24 @@ import (
 )
 
 // Update updates pull request with base branch.
-func Update(pull *models.PullRequest, doer *models.User, message string) error {
-	//use merge functions but switch repo's and branch's
-	pr := &models.PullRequest{
-		HeadRepoID: pull.BaseRepoID,
-		BaseRepoID: pull.HeadRepoID,
-		HeadBranch: pull.BaseBranch,
-		BaseBranch: pull.HeadBranch,
+func Update(pull *models.PullRequest, doer *models.User, message string, rebase bool) error {
+	var (
+		pr    *models.PullRequest
+		style models.MergeStyle
+	)
+
+	if rebase {
+		pr = pull
+		style = models.MergeStyleRebaseUpdate
+	} else {
+		//use merge functions but switch repo's and branch's
+		pr = &models.PullRequest{
+			HeadRepoID: pull.BaseRepoID,
+			BaseRepoID: pull.HeadRepoID,
+			HeadBranch: pull.BaseBranch,
+			BaseBranch: pull.HeadBranch,
+		}
+		style = models.MergeStyleMerge
 	}
 
 	if pull.Flow == models.PullRequestFlowAGit {
@@ -42,9 +53,13 @@ func Update(pull *models.PullRequest, doer *models.User, message string) error {
 		return fmt.Errorf("HeadBranch of PR %d is up to date", pull.Index)
 	}
 
-	_, err = rawMerge(pr, doer, models.MergeStyleMerge, message)
+	_, err = rawMerge(pr, doer, style, message)
 
 	defer func() {
+		if rebase {
+			go AddTestPullRequestTask(doer, pr.BaseRepo.ID, pr.BaseBranch, false, "", "")
+			return
+		}
 		go AddTestPullRequestTask(doer, pr.HeadRepo.ID, pr.HeadBranch, false, "", "")
 	}()
 
@@ -52,17 +67,17 @@ func Update(pull *models.PullRequest, doer *models.User, message string) error {
 }
 
 // IsUserAllowedToUpdate check if user is allowed to update PR with given permissions and branch protections
-func IsUserAllowedToUpdate(pull *models.PullRequest, user *models.User) (bool, error) {
+func IsUserAllowedToUpdate(pull *models.PullRequest, user *models.User) (mergeAllowed, rebaseAllowed bool, err error) {
 	if pull.Flow == models.PullRequestFlowAGit {
-		return false, nil
+		return false, false, nil
 	}
 
 	if user == nil {
-		return false, nil
+		return false, false, nil
 	}
 	headRepoPerm, err := models.GetUserRepoPermission(pull.HeadRepo, user)
 	if err != nil {
-		return false, err
+		return false, false, err
 	}
 
 	pr := &models.PullRequest{
@@ -74,15 +89,25 @@ func IsUserAllowedToUpdate(pull *models.PullRequest, user *models.User) (bool, e
 
 	err = pr.LoadProtectedBranch()
 	if err != nil {
-		return false, err
+		return false, false, err
+	}
+
+	// can't do rebase on protected branch because need force push
+	if pr.ProtectedBranch == nil {
+		rebaseAllowed = true
 	}
 
 	// Update function need push permission
 	if pr.ProtectedBranch != nil && !pr.ProtectedBranch.CanUserPush(user.ID) {
-		return false, nil
+		return false, false, nil
+	}
+
+	mergeAllowed, err = IsUserAllowedToMerge(pr, headRepoPerm, user)
+	if err != nil {
+		return false, false, err
 	}
 
-	return IsUserAllowedToMerge(pr, headRepoPerm, user)
+	return mergeAllowed, rebaseAllowed, nil
 }
 
 // GetDiverging determines how many commits a PR is ahead or behind the PR base branch