Approvals at Branch Protection (#5350)

* Add branch protection for approvals

Signed-off-by: Jonas Franz <info@jonasfranz.software>

* Add required approvals

Signed-off-by: Jonas Franz <info@jonasfranz.software>

* Add missing comments and fmt

Signed-off-by: Jonas Franz <info@jonasfranz.software>

* Add type = approval and group by reviewer_id to review

* Prevent users from adding negative review limits

* Add migration for approval whitelists

Signed-off-by: Jonas Franz <info@jonasfranz.software>

7 files changed, 156 insertions, 30 deletions

diff --git a/models/branches.go b/models/branches.go
index bbcd342baa..f2bf9a80a0 100644
--- a/models/branches.go
+++ b/models/branches.go
@@ -23,18 +23,21 @@ const (
 
 // ProtectedBranch struct
 type ProtectedBranch struct {
-	ID                    int64  `xorm:"pk autoincr"`
-	RepoID                int64  `xorm:"UNIQUE(s)"`
-	BranchName            string `xorm:"UNIQUE(s)"`
-	CanPush               bool   `xorm:"NOT NULL DEFAULT false"`
-	EnableWhitelist       bool
-	WhitelistUserIDs      []int64        `xorm:"JSON TEXT"`
-	WhitelistTeamIDs      []int64        `xorm:"JSON TEXT"`
-	EnableMergeWhitelist  bool           `xorm:"NOT NULL DEFAULT false"`
-	MergeWhitelistUserIDs []int64        `xorm:"JSON TEXT"`
-	MergeWhitelistTeamIDs []int64        `xorm:"JSON TEXT"`
-	CreatedUnix           util.TimeStamp `xorm:"created"`
-	UpdatedUnix           util.TimeStamp `xorm:"updated"`
+	ID                        int64  `xorm:"pk autoincr"`
+	RepoID                    int64  `xorm:"UNIQUE(s)"`
+	BranchName                string `xorm:"UNIQUE(s)"`
+	CanPush                   bool   `xorm:"NOT NULL DEFAULT false"`
+	EnableWhitelist           bool
+	WhitelistUserIDs          []int64        `xorm:"JSON TEXT"`
+	WhitelistTeamIDs          []int64        `xorm:"JSON TEXT"`
+	EnableMergeWhitelist      bool           `xorm:"NOT NULL DEFAULT false"`
+	MergeWhitelistUserIDs     []int64        `xorm:"JSON TEXT"`
+	MergeWhitelistTeamIDs     []int64        `xorm:"JSON TEXT"`
+	ApprovalsWhitelistUserIDs []int64        `xorm:"JSON TEXT"`
+	ApprovalsWhitelistTeamIDs []int64        `xorm:"JSON TEXT"`
+	RequiredApprovals         int64          `xorm:"NOT NULL DEFAULT 0"`
+	CreatedUnix               util.TimeStamp `xorm:"created"`
+	UpdatedUnix               util.TimeStamp `xorm:"updated"`
 }
 
 // IsProtected returns if the branch is protected
@@ -86,6 +89,41 @@ func (protectBranch *ProtectedBranch) CanUserMerge(userID int64) bool {
 	return in
 }
 
+// HasEnoughApprovals returns true if pr has enough granted approvals.
+func (protectBranch *ProtectedBranch) HasEnoughApprovals(pr *PullRequest) bool {
+	if protectBranch.RequiredApprovals == 0 {
+		return true
+	}
+	return protectBranch.GetGrantedApprovalsCount(pr) >= protectBranch.RequiredApprovals
+}
+
+// GetGrantedApprovalsCount returns the number of granted approvals for pr. A granted approval must be authored by a user in an approval whitelist.
+func (protectBranch *ProtectedBranch) GetGrantedApprovalsCount(pr *PullRequest) int64 {
+	reviews, err := GetReviewersByPullID(pr.ID)
+	if err != nil {
+		log.Error(1, "GetUniqueApprovalsByPullRequestID:", err)
+		return 0
+	}
+	approvals := int64(0)
+	userIDs := make([]int64, 0)
+	for _, review := range reviews {
+		if review.Type != ReviewTypeApprove {
+			continue
+		}
+		if base.Int64sContains(protectBranch.ApprovalsWhitelistUserIDs, review.ID) {
+			approvals++
+			continue
+		}
+		userIDs = append(userIDs, review.ID)
+	}
+	approvalTeamCount, err := UsersInTeamsCount(userIDs, protectBranch.ApprovalsWhitelistTeamIDs)
+	if err != nil {
+		log.Error(1, "UsersInTeamsCount:", err)
+		return 0
+	}
+	return approvalTeamCount + approvals
+}
+
 // GetProtectedBranchByRepoID getting protected branch by repo ID
 func GetProtectedBranchByRepoID(RepoID int64) ([]*ProtectedBranch, error) {
 	protectedBranches := make([]*ProtectedBranch, 0)
@@ -118,40 +156,64 @@ func GetProtectedBranchByID(id int64) (*ProtectedBranch, error) {
 	return rel, nil
 }
 
+// WhitelistOptions represent all sorts of whitelists used for protected branches
+type WhitelistOptions struct {
+	UserIDs []int64
+	TeamIDs []int64
+
+	MergeUserIDs []int64
+	MergeTeamIDs []int64
+
+	ApprovalsUserIDs []int64
+	ApprovalsTeamIDs []int64
+}
+
 // UpdateProtectBranch saves branch protection options of repository.
 // If ID is 0, it creates a new record. Otherwise, updates existing record.
 // This function also performs check if whitelist user and team's IDs have been changed
 // to avoid unnecessary whitelist delete and regenerate.
-func UpdateProtectBranch(repo *Repository, protectBranch *ProtectedBranch, whitelistUserIDs, whitelistTeamIDs, mergeWhitelistUserIDs, mergeWhitelistTeamIDs []int64) (err error) {
+func UpdateProtectBranch(repo *Repository, protectBranch *ProtectedBranch, opts WhitelistOptions) (err error) {
 	if err = repo.GetOwner(); err != nil {
 		return fmt.Errorf("GetOwner: %v", err)
 	}
 
-	whitelist, err := updateUserWhitelist(repo, protectBranch.WhitelistUserIDs, whitelistUserIDs)
+	whitelist, err := updateUserWhitelist(repo, protectBranch.WhitelistUserIDs, opts.UserIDs)
 	if err != nil {
 		return err
 	}
 	protectBranch.WhitelistUserIDs = whitelist
 
-	whitelist, err = updateUserWhitelist(repo, protectBranch.MergeWhitelistUserIDs, mergeWhitelistUserIDs)
+	whitelist, err = updateUserWhitelist(repo, protectBranch.MergeWhitelistUserIDs, opts.MergeUserIDs)
 	if err != nil {
 		return err
 	}
 	protectBranch.MergeWhitelistUserIDs = whitelist
 
+	whitelist, err = updateUserWhitelist(repo, protectBranch.ApprovalsWhitelistUserIDs, opts.ApprovalsUserIDs)
+	if err != nil {
+		return err
+	}
+	protectBranch.ApprovalsWhitelistUserIDs = whitelist
+
 	// if the repo is in an organization
-	whitelist, err = updateTeamWhitelist(repo, protectBranch.WhitelistTeamIDs, whitelistTeamIDs)
+	whitelist, err = updateTeamWhitelist(repo, protectBranch.WhitelistTeamIDs, opts.TeamIDs)
 	if err != nil {
 		return err
 	}
 	protectBranch.WhitelistTeamIDs = whitelist
 
-	whitelist, err = updateTeamWhitelist(repo, protectBranch.MergeWhitelistTeamIDs, mergeWhitelistTeamIDs)
+	whitelist, err = updateTeamWhitelist(repo, protectBranch.MergeWhitelistTeamIDs, opts.MergeTeamIDs)
 	if err != nil {
 		return err
 	}
 	protectBranch.MergeWhitelistTeamIDs = whitelist
 
+	whitelist, err = updateTeamWhitelist(repo, protectBranch.ApprovalsWhitelistTeamIDs, opts.ApprovalsTeamIDs)
+	if err != nil {
+		return err
+	}
+	protectBranch.ApprovalsWhitelistTeamIDs = whitelist
+
 	// Make sure protectBranch.ID is not 0 for whitelists
 	if protectBranch.ID == 0 {
 		if _, err = x.Insert(protectBranch); err != nil {
@@ -213,7 +275,7 @@ func (repo *Repository) IsProtectedBranchForPush(branchName string, doer *User)
 }
 
 // IsProtectedBranchForMerging checks if branch is protected for merging
-func (repo *Repository) IsProtectedBranchForMerging(branchName string, doer *User) (bool, error) {
+func (repo *Repository) IsProtectedBranchForMerging(pr *PullRequest, branchName string, doer *User) (bool, error) {
 	if doer == nil {
 		return true, nil
 	}
@@ -227,7 +289,7 @@ func (repo *Repository) IsProtectedBranchForMerging(branchName string, doer *Use
 	if err != nil {
 		return true, err
 	} else if has {
-		return !protectedBranch.CanUserMerge(doer.ID), nil
+		return !protectedBranch.CanUserMerge(doer.ID) || !protectedBranch.HasEnoughApprovals(pr), nil
 	}
 
 	return false, nil
@@ -270,14 +332,14 @@ func updateTeamWhitelist(repo *Repository, currentWhitelist, newWhitelist []int6
 		return currentWhitelist, nil
 	}
 
-	teams, err := GetTeamsWithAccessToRepo(repo.OwnerID, repo.ID, AccessModeWrite)
+	teams, err := GetTeamsWithAccessToRepo(repo.OwnerID, repo.ID, AccessModeRead)
 	if err != nil {
 		return nil, fmt.Errorf("GetTeamsWithAccessToRepo [org_id: %d, repo_id: %d]: %v", repo.OwnerID, repo.ID, err)
 	}
 
 	whitelist = make([]int64, 0, len(teams))
 	for i := range teams {
-		if teams[i].HasWriteAccess() && com.IsSliceContainsInt64(newWhitelist, teams[i].ID) {
+		if com.IsSliceContainsInt64(newWhitelist, teams[i].ID) {
 			whitelist = append(whitelist, teams[i].ID)
 		}
 	}
diff --git a/models/migrations/migrations.go b/models/migrations/migrations.go
index 6ac5004eb1..6c28989c2e 100644
--- a/models/migrations/migrations.go
+++ b/models/migrations/migrations.go
@@ -200,6 +200,8 @@ var migrations = []Migration{
 	NewMigration("add review", addReview),
 	// v73 -> v74
 	NewMigration("add must_change_password column for users table", addMustChangePassword),
+	// v74 -> v75
+	NewMigration("add approval whitelists to protected branches", addApprovalWhitelistsToProtectedBranches),
 }
 
 // Migrate database to current version
diff --git a/models/migrations/v74.go b/models/migrations/v74.go
new file mode 100644
index 0000000000..66e958c7fa
--- /dev/null
+++ b/models/migrations/v74.go
@@ -0,0 +1,16 @@
+// Copyright 2018 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package migrations
+
+import "github.com/go-xorm/xorm"
+
+func addApprovalWhitelistsToProtectedBranches(x *xorm.Engine) error {
+	type ProtectedBranch struct {
+		ApprovalsWhitelistUserIDs []int64 `xorm:"JSON TEXT"`
+		ApprovalsWhitelistTeamIDs []int64 `xorm:"JSON TEXT"`
+		RequiredApprovals         int64   `xorm:"NOT NULL DEFAULT 0"`
+	}
+	return x.Sync2(new(ProtectedBranch))
+}
diff --git a/models/org_team.go b/models/org_team.go
index cad4af2506..34e1b4db83 100644
--- a/models/org_team.go
+++ b/models/org_team.go
@@ -700,6 +700,14 @@ func IsUserInTeams(userID int64, teamIDs []int64) (bool, error) {
 	return x.Where("uid=?", userID).In("team_id", teamIDs).Exist(new(TeamUser))
 }
 
+// UsersInTeamsCount counts the number of users which are in userIDs and teamIDs
+func UsersInTeamsCount(userIDs []int64, teamIDs []int64) (count int64, err error) {
+	if count, err = x.In("uid", userIDs).In("team_id", teamIDs).Count(new(TeamUser)); err != nil {
+		return 0, err
+	}
+	return
+}
+
 // ___________                  __________
 // \__    ___/___ _____    _____\______   \ ____ ______   ____
 //   |    |_/ __ \\__  \  /     \|       _// __ \\____ \ /  _ \
diff --git a/models/org_team_test.go b/models/org_team_test.go
index f9f1f289ec..87bfbb4841 100644
--- a/models/org_team_test.go
+++ b/models/org_team_test.go
@@ -346,3 +346,17 @@ func TestHasTeamRepo(t *testing.T) {
 	test(2, 3, true)
 	test(2, 5, false)
 }
+
+func TestUsersInTeamsCount(t *testing.T) {
+	assert.NoError(t, PrepareTestDatabase())
+
+	test := func(teamIDs []int64, userIDs []int64, expected int64) {
+		count, err := UsersInTeamsCount(teamIDs, userIDs)
+		assert.NoError(t, err)
+		assert.Equal(t, expected, count)
+	}
+
+	test([]int64{2}, []int64{1, 2, 3, 4}, 2)
+	test([]int64{1, 2, 3, 4, 5}, []int64{2, 5}, 2)
+	test([]int64{1, 2, 3, 4, 5}, []int64{2, 3, 5}, 3)
+}
diff --git a/models/pull.go b/models/pull.go
index e97faa8f51..0041f83dc8 100644
--- a/models/pull.go
+++ b/models/pull.go
@@ -60,14 +60,15 @@ type PullRequest struct {
 	Issue   *Issue `xorm:"-"`
 	Index   int64
 
-	HeadRepoID   int64       `xorm:"INDEX"`
-	HeadRepo     *Repository `xorm:"-"`
-	BaseRepoID   int64       `xorm:"INDEX"`
-	BaseRepo     *Repository `xorm:"-"`
-	HeadUserName string
-	HeadBranch   string
-	BaseBranch   string
-	MergeBase    string `xorm:"VARCHAR(40)"`
+	HeadRepoID      int64       `xorm:"INDEX"`
+	HeadRepo        *Repository `xorm:"-"`
+	BaseRepoID      int64       `xorm:"INDEX"`
+	BaseRepo        *Repository `xorm:"-"`
+	HeadUserName    string
+	HeadBranch      string
+	BaseBranch      string
+	ProtectedBranch *ProtectedBranch `xorm:"-"`
+	MergeBase       string           `xorm:"VARCHAR(40)"`
 
 	HasMerged      bool           `xorm:"INDEX"`
 	MergedCommitID string         `xorm:"VARCHAR(40)"`
@@ -110,6 +111,12 @@ func (pr *PullRequest) loadIssue(e Engine) (err error) {
 	return err
 }
 
+// LoadProtectedBranch loads the protected branch of the base branch
+func (pr *PullRequest) LoadProtectedBranch() (err error) {
+	pr.ProtectedBranch, err = GetProtectedBranchBy(pr.BaseRepo.ID, pr.BaseBranch)
+	return
+}
+
 // GetDefaultMergeMessage returns default message used when merging pull request
 func (pr *PullRequest) GetDefaultMergeMessage() string {
 	if pr.HeadRepo == nil {
@@ -288,7 +295,7 @@ func (pr *PullRequest) CheckUserAllowedToMerge(doer *User) (err error) {
 		}
 	}
 
-	if protected, err := pr.BaseRepo.IsProtectedBranchForMerging(pr.BaseBranch, doer); err != nil {
+	if protected, err := pr.BaseRepo.IsProtectedBranchForMerging(pr, pr.BaseBranch, doer); err != nil {
 		return fmt.Errorf("IsProtectedBranch: %v", err)
 	} else if protected {
 		return ErrNotAllowedToMerge{
diff --git a/models/review.go b/models/review.go
index 3ae1dd457c..91b6d6dbb2 100644
--- a/models/review.go
+++ b/models/review.go
@@ -161,6 +161,23 @@ func GetReviewByID(id int64) (*Review, error) {
 	return getReviewByID(x, id)
 }
 
+func getUniqueApprovalsByPullRequestID(e Engine, prID int64) (reviews []*Review, err error) {
+	reviews = make([]*Review, 0)
+	if err := e.
+		Where("issue_id = ? AND type = ?", prID, ReviewTypeApprove).
+		OrderBy("updated_unix").
+		GroupBy("reviewer_id").
+		Find(&reviews); err != nil {
+		return nil, err
+	}
+	return
+}
+
+// GetUniqueApprovalsByPullRequestID returns all reviews submitted for a specific pull request
+func GetUniqueApprovalsByPullRequestID(prID int64) ([]*Review, error) {
+	return getUniqueApprovalsByPullRequestID(x, prID)
+}
+
 // FindReviewOptions represent possible filters to find reviews
 type FindReviewOptions struct {
 	Type       ReviewType