1 files changed, 404 insertions, 0 deletions

diff --git a/services/pull/check.go b/services/pull/check.go
new file mode 100644
index 0000000..2d91ed0
--- /dev/null
+++ b/services/pull/check.go
@@ -0,0 +1,404 @@
+// Copyright 2019 The Gitea Authors.
+// All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package pull
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"strconv"
+	"strings"
+
+	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
+	git_model "code.gitea.io/gitea/models/git"
+	issues_model "code.gitea.io/gitea/models/issues"
+	access_model "code.gitea.io/gitea/models/perm/access"
+	repo_model "code.gitea.io/gitea/models/repo"
+	"code.gitea.io/gitea/models/unit"
+	user_model "code.gitea.io/gitea/models/user"
+	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/gitrepo"
+	"code.gitea.io/gitea/modules/graceful"
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/process"
+	"code.gitea.io/gitea/modules/queue"
+	"code.gitea.io/gitea/modules/timeutil"
+	asymkey_service "code.gitea.io/gitea/services/asymkey"
+	notify_service "code.gitea.io/gitea/services/notify"
+)
+
+// prPatchCheckerQueue represents a queue to handle update pull request tests
+var prPatchCheckerQueue *queue.WorkerPoolQueue[string]
+
+var (
+	ErrIsClosed              = errors.New("pull is closed")
+	ErrUserNotAllowedToMerge = models.ErrDisallowedToMerge{}
+	ErrHasMerged             = errors.New("has already been merged")
+	ErrIsWorkInProgress      = errors.New("work in progress PRs cannot be merged")
+	ErrIsChecking            = errors.New("cannot merge while conflict checking is in progress")
+	ErrNotMergeableState     = errors.New("not in mergeable state")
+	ErrDependenciesLeft      = errors.New("is blocked by an open dependency")
+)
+
+// AddToTaskQueue adds itself to pull request test task queue.
+func AddToTaskQueue(ctx context.Context, pr *issues_model.PullRequest) {
+	pr.Status = issues_model.PullRequestStatusChecking
+	err := pr.UpdateColsIfNotMerged(ctx, "status")
+	if err != nil {
+		log.Error("AddToTaskQueue(%-v).UpdateCols.(add to queue): %v", pr, err)
+		return
+	}
+	log.Trace("Adding %-v to the test pull requests queue", pr)
+	err = prPatchCheckerQueue.Push(strconv.FormatInt(pr.ID, 10))
+	if err != nil && err != queue.ErrAlreadyInQueue {
+		log.Error("Error adding %-v to the test pull requests queue: %v", pr, err)
+	}
+}
+
+type MergeCheckType int
+
+const (
+	MergeCheckTypeGeneral  MergeCheckType = iota // general merge checks for "merge", "rebase", "squash", etc
+	MergeCheckTypeManually                       // Manually Merged button (mark a PR as merged manually)
+	MergeCheckTypeAuto                           // Auto Merge (Scheduled Merge) After Checks Succeed
+)
+
+// CheckPullMergeable check if the pull mergeable based on all conditions (branch protection, merge options, ...)
+func CheckPullMergeable(stdCtx context.Context, doer *user_model.User, perm *access_model.Permission, pr *issues_model.PullRequest, mergeCheckType MergeCheckType, adminSkipProtectionCheck bool) error {
+	return db.WithTx(stdCtx, func(ctx context.Context) error {
+		if pr.HasMerged {
+			return ErrHasMerged
+		}
+
+		if err := pr.LoadIssue(ctx); err != nil {
+			log.Error("Unable to load issue[%d] for %-v: %v", pr.IssueID, pr, err)
+			return err
+		} else if pr.Issue.IsClosed {
+			return ErrIsClosed
+		}
+
+		if allowedMerge, err := IsUserAllowedToMerge(ctx, pr, *perm, doer); err != nil {
+			log.Error("Error whilst checking if %-v is allowed to merge %-v: %v", doer, pr, err)
+			return err
+		} else if !allowedMerge {
+			return ErrUserNotAllowedToMerge
+		}
+
+		if mergeCheckType == MergeCheckTypeManually {
+			// if doer is doing "manually merge" (mark as merged manually), do not check anything
+			return nil
+		}
+
+		if pr.IsWorkInProgress(ctx) {
+			return ErrIsWorkInProgress
+		}
+
+		if !pr.CanAutoMerge() && !pr.IsEmpty() {
+			return ErrNotMergeableState
+		}
+
+		if pr.IsChecking() {
+			return ErrIsChecking
+		}
+
+		if pb, err := CheckPullBranchProtections(ctx, pr, false); err != nil {
+			if !models.IsErrDisallowedToMerge(err) {
+				log.Error("Error whilst checking pull branch protection for %-v: %v", pr, err)
+				return err
+			}
+
+			// Now the branch protection check failed, check whether the failure could be skipped (skip by setting err = nil)
+
+			// * when doing Auto Merge (Scheduled Merge After Checks Succeed), skip the branch protection check
+			if mergeCheckType == MergeCheckTypeAuto {
+				err = nil
+			}
+
+			// * if the doer is admin, they could skip the branch protection check,
+			// if that's allowed by the protected branch rule.
+			if adminSkipProtectionCheck {
+				if doer.IsAdmin {
+					err = nil // instance admin can skip the check, so clear the error
+				} else if !pb.ApplyToAdmins {
+					if isRepoAdmin, errCheckAdmin := access_model.IsUserRepoAdmin(ctx, pr.BaseRepo, doer); errCheckAdmin != nil {
+						log.Error("Unable to check if %-v is a repo admin in %-v: %v", doer, pr.BaseRepo, errCheckAdmin)
+						return errCheckAdmin
+					} else if isRepoAdmin {
+						err = nil // repo admin can skip the check, so clear the error
+					}
+				}
+			}
+
+			// If there is still a branch protection check error, return it
+			if err != nil {
+				return err
+			}
+		}
+
+		if _, err := isSignedIfRequired(ctx, pr, doer); err != nil {
+			return err
+		}
+
+		if noDeps, err := issues_model.IssueNoDependenciesLeft(ctx, pr.Issue); err != nil {
+			return err
+		} else if !noDeps {
+			return ErrDependenciesLeft
+		}
+
+		return nil
+	})
+}
+
+// isSignedIfRequired check if merge will be signed if required
+func isSignedIfRequired(ctx context.Context, pr *issues_model.PullRequest, doer *user_model.User) (bool, error) {
+	pb, err := git_model.GetFirstMatchProtectedBranchRule(ctx, pr.BaseRepoID, pr.BaseBranch)
+	if err != nil {
+		return false, err
+	}
+
+	if pb == nil || !pb.RequireSignedCommits {
+		return true, nil
+	}
+
+	sign, _, _, err := asymkey_service.SignMerge(ctx, pr, doer, pr.BaseRepo.RepoPath(), pr.BaseBranch, pr.GetGitRefName())
+
+	return sign, err
+}
+
+// checkAndUpdateStatus checks if pull request is possible to leaving checking status,
+// and set to be either conflict or mergeable.
+func checkAndUpdateStatus(ctx context.Context, pr *issues_model.PullRequest) {
+	// If status has not been changed to conflict by testPatch then we are mergeable
+	if pr.Status == issues_model.PullRequestStatusChecking {
+		pr.Status = issues_model.PullRequestStatusMergeable
+	}
+
+	// Make sure there is no waiting test to process before leaving the checking status.
+	has, err := prPatchCheckerQueue.Has(strconv.FormatInt(pr.ID, 10))
+	if err != nil {
+		log.Error("Unable to check if the queue is waiting to reprocess %-v. Error: %v", pr, err)
+	}
+
+	if has {
+		log.Trace("Not updating status for %-v as it is due to be rechecked", pr)
+		return
+	}
+
+	if err := pr.UpdateColsIfNotMerged(ctx, "merge_base", "status", "conflicted_files", "changed_protected_files"); err != nil {
+		log.Error("Update[%-v]: %v", pr, err)
+	}
+}
+
+// getMergeCommit checks if a pull request has been merged
+// Returns the git.Commit of the pull request if merged
+func getMergeCommit(ctx context.Context, pr *issues_model.PullRequest) (*git.Commit, error) {
+	if err := pr.LoadBaseRepo(ctx); err != nil {
+		return nil, fmt.Errorf("unable to load base repo for %s: %w", pr, err)
+	}
+
+	prHeadRef := pr.GetGitRefName()
+
+	// Check if the pull request is merged into BaseBranch
+	if _, _, err := git.NewCommand(ctx, "merge-base", "--is-ancestor").
+		AddDynamicArguments(prHeadRef, pr.BaseBranch).
+		RunStdString(&git.RunOpts{Dir: pr.BaseRepo.RepoPath()}); err != nil {
+		if strings.Contains(err.Error(), "exit status 1") {
+			// prHeadRef is not an ancestor of the base branch
+			return nil, nil
+		}
+		// Errors are signaled by a non-zero status that is not 1
+		return nil, fmt.Errorf("%-v git merge-base --is-ancestor: %w", pr, err)
+	}
+
+	// If merge-base successfully exits then prHeadRef is an ancestor of pr.BaseBranch
+
+	// Find the head commit id
+	prHeadCommitID, err := git.GetFullCommitID(ctx, pr.BaseRepo.RepoPath(), prHeadRef)
+	if err != nil {
+		return nil, fmt.Errorf("GetFullCommitID(%s) in %s: %w", prHeadRef, pr.BaseRepo.FullName(), err)
+	}
+
+	gitRepo, err := gitrepo.OpenRepository(ctx, pr.BaseRepo)
+	if err != nil {
+		return nil, fmt.Errorf("%-v OpenRepository: %w", pr.BaseRepo, err)
+	}
+	defer gitRepo.Close()
+
+	objectFormat := git.ObjectFormatFromName(pr.BaseRepo.ObjectFormatName)
+
+	// Get the commit from BaseBranch where the pull request got merged
+	mergeCommit, _, err := git.NewCommand(ctx, "rev-list", "--ancestry-path", "--merges", "--reverse").
+		AddDynamicArguments(prHeadCommitID + ".." + pr.BaseBranch).
+		RunStdString(&git.RunOpts{Dir: pr.BaseRepo.RepoPath()})
+	if err != nil {
+		return nil, fmt.Errorf("git rev-list --ancestry-path --merges --reverse: %w", err)
+	} else if len(mergeCommit) < objectFormat.FullLength() {
+		// PR was maybe fast-forwarded, so just use last commit of PR
+		mergeCommit = prHeadCommitID
+	}
+	mergeCommit = strings.TrimSpace(mergeCommit)
+
+	commit, err := gitRepo.GetCommit(mergeCommit)
+	if err != nil {
+		return nil, fmt.Errorf("GetMergeCommit[%s]: %w", mergeCommit, err)
+	}
+
+	return commit, nil
+}
+
+// manuallyMerged checks if a pull request got manually merged
+// When a pull request got manually merged mark the pull request as merged
+func manuallyMerged(ctx context.Context, pr *issues_model.PullRequest) bool {
+	if err := pr.LoadBaseRepo(ctx); err != nil {
+		log.Error("%-v LoadBaseRepo: %v", pr, err)
+		return false
+	}
+
+	if unit, err := pr.BaseRepo.GetUnit(ctx, unit.TypePullRequests); err == nil {
+		config := unit.PullRequestsConfig()
+		if !config.AutodetectManualMerge {
+			return false
+		}
+	} else {
+		log.Error("%-v BaseRepo.GetUnit(unit.TypePullRequests): %v", pr, err)
+		return false
+	}
+
+	commit, err := getMergeCommit(ctx, pr)
+	if err != nil {
+		log.Error("%-v getMergeCommit: %v", pr, err)
+		return false
+	}
+
+	if commit == nil {
+		// no merge commit found
+		return false
+	}
+
+	pr.MergedCommitID = commit.ID.String()
+	pr.MergedUnix = timeutil.TimeStamp(commit.Author.When.Unix())
+	pr.Status = issues_model.PullRequestStatusManuallyMerged
+	merger, _ := user_model.GetUserByEmail(ctx, commit.Author.Email)
+
+	// When the commit author is unknown set the BaseRepo owner as merger
+	if merger == nil {
+		if pr.BaseRepo.Owner == nil {
+			if err = pr.BaseRepo.LoadOwner(ctx); err != nil {
+				log.Error("%-v BaseRepo.LoadOwner: %v", pr, err)
+				return false
+			}
+		}
+		merger = pr.BaseRepo.Owner
+	}
+	pr.Merger = merger
+	pr.MergerID = merger.ID
+
+	if merged, err := pr.SetMerged(ctx); err != nil {
+		log.Error("%-v setMerged : %v", pr, err)
+		return false
+	} else if !merged {
+		return false
+	}
+
+	notify_service.MergePullRequest(ctx, merger, pr)
+
+	log.Info("manuallyMerged[%-v]: Marked as manually merged into %s/%s by commit id: %s", pr, pr.BaseRepo.Name, pr.BaseBranch, commit.ID.String())
+	return true
+}
+
+// InitializePullRequests checks and tests untested patches of pull requests.
+func InitializePullRequests(ctx context.Context) {
+	prs, err := issues_model.GetPullRequestIDsByCheckStatus(ctx, issues_model.PullRequestStatusChecking)
+	if err != nil {
+		log.Error("Find Checking PRs: %v", err)
+		return
+	}
+	for _, prID := range prs {
+		select {
+		case <-ctx.Done():
+			return
+		default:
+			log.Trace("Adding PR[%d] to the pull requests patch checking queue", prID)
+			if err := prPatchCheckerQueue.Push(strconv.FormatInt(prID, 10)); err != nil {
+				log.Error("Error adding PR[%d] to the pull requests patch checking queue %v", prID, err)
+			}
+		}
+	}
+}
+
+// handle passed PR IDs and test the PRs
+func handler(items ...string) []string {
+	for _, s := range items {
+		id, _ := strconv.ParseInt(s, 10, 64)
+		testPR(id)
+	}
+	return nil
+}
+
+func testPR(id int64) {
+	pullWorkingPool.CheckIn(fmt.Sprint(id))
+	defer pullWorkingPool.CheckOut(fmt.Sprint(id))
+	ctx, _, finished := process.GetManager().AddContext(graceful.GetManager().HammerContext(), fmt.Sprintf("Test PR[%d] from patch checking queue", id))
+	defer finished()
+
+	pr, err := issues_model.GetPullRequestByID(ctx, id)
+	if err != nil {
+		log.Error("Unable to GetPullRequestByID[%d] for testPR: %v", id, err)
+		return
+	}
+
+	log.Trace("Testing %-v", pr)
+	defer func() {
+		log.Trace("Done testing %-v (status: %s)", pr, pr.Status)
+	}()
+
+	if pr.HasMerged {
+		log.Trace("%-v is already merged (status: %s, merge commit: %s)", pr, pr.Status, pr.MergedCommitID)
+		return
+	}
+
+	if manuallyMerged(ctx, pr) {
+		log.Trace("%-v is manually merged (status: %s, merge commit: %s)", pr, pr.Status, pr.MergedCommitID)
+		return
+	}
+
+	if err := TestPatch(pr); err != nil {
+		log.Error("testPatch[%-v]: %v", pr, err)
+		pr.Status = issues_model.PullRequestStatusError
+		if err := pr.UpdateCols(ctx, "status"); err != nil {
+			log.Error("update pr [%-v] status to PullRequestStatusError failed: %v", pr, err)
+		}
+		return
+	}
+	checkAndUpdateStatus(ctx, pr)
+}
+
+// CheckPRsForBaseBranch check all pulls with baseBrannch
+func CheckPRsForBaseBranch(ctx context.Context, baseRepo *repo_model.Repository, baseBranchName string) error {
+	prs, err := issues_model.GetUnmergedPullRequestsByBaseInfo(ctx, baseRepo.ID, baseBranchName)
+	if err != nil {
+		return err
+	}
+
+	for _, pr := range prs {
+		AddToTaskQueue(ctx, pr)
+	}
+
+	return nil
+}
+
+// Init runs the task queue to test all the checking status pull requests
+func Init() error {
+	prPatchCheckerQueue = queue.CreateUniqueQueue(graceful.GetManager().ShutdownContext(), "pr_patch_checker", handler)
+
+	if prPatchCheckerQueue == nil {
+		return fmt.Errorf("unable to create pr_patch_checker queue")
+	}
+
+	go graceful.GetManager().RunWithCancel(prPatchCheckerQueue)
+	go graceful.GetManager().RunWithShutdownContext(InitializePullRequests)
+	return nil
+}