Stale branches cleanup 🧹

README.md

@@ -8,6 +8,7 @@
 - rule for approvers
 - merge on command
 - update branch
+- delete stale branches
 
 
 ### Commands
@@ -44,23 +45,29 @@ go build ./
 
 ## Config file
 
-Config file must be named `.mrbot.yaml` and placed in root directory
+Config file must be named `.mrbot.yaml`, placed in root directory, default branch (main/master)
 
-- `approvers`: list of users who must approve MR/PR, default is empty (`[]`)
+```yaml
+approvers: [] # list of users who must approve MR/PR, default is empty ([])
 
-- `min_approvals`: minimum number of required approvals, default is `1`
+min_approvals: 1 # minimum number of required approvals, default is 1
 
-- `allow_empty_description`: whether MR description is allowed to be empty or not, default is `true`
+allow_empty_description: true # whether MR description is allowed to be empty or not, default is true
 
-- `allow_failing_pipelines`: whether pipelines are allowed to fail, default is `true`
+allow_failing_pipelines: true # whether pipelines are allowed to fail, default is true
 
-- `title_regex`: pattern of title, default is `.*`
+title_regex: ".*" # pattern of title, default is ".*"
 
-- `greetings_enabled`: enable message for new MR, default is `false`
+greetings:
+  enabled: false # enable message for new MR, default is false
+  template: "" # template of message for new MR, default is "Requirements:\n - Min approvals: {{ .MinApprovals }}\n - Title regex: {{ .TitleRegex }}\n\nOnce you've done, send **!merge** command and i will merge it!"
 
-- `greetings_template`: template of message for new MR, default is `Requirements:\n - Min approvals: {{ .MinApprovals }}\n - Title regex: {{ .TitleRegex }}\n\nOnce you've done, send **!merge** command and i will merge it!`
+auto_master_merge: false # the bot tries to update branch from master, default is false
 
-- `auto_master_merge`: the bot tries to merge target branch, default is `false`
+stale_branches_deletion:
+  enabled: false # enable deletion of stale branches after every merge, default is false
+  days: 90 # branch is staled after int days, default is 90
+```
 
 Example:
 
@@ -73,9 +80,13 @@ allow_empty_description: true
 allow_failing_pipelines: true
 allow_failing_tests: true
 title_regex: "^[A-Z]+-[0-9]+" # title begins with jira key prefix, e.g. SCO-123 My cool Title
-greetings_enabled: true
-greetings_template: "Requirements:\n - Min approvals: {{ .MinApprovals }}\n - Title regex: {{ .TitleRegex }}\n\nOnce you've done, send **!merge** command and i will merge it!"
+greetings:
+  enabled: true
+  template: "Requirements:\n - Min approvals: {{ .MinApprovals }}\n - Title regex: {{ .TitleRegex }}\n\nOnce you've done, send **!merge** command and i will merge it!"
 auto_master_merge: true
+stale_branches_deletion:
+  enabled: true
+  days: 90
 ```
 
 place it in root of your repo and name it `.mrbot.yaml`

handlers/gitlab/gitlab.go

@@ -188,6 +188,28 @@ func (g *GitlabProvider) GetMRInfo(projectId, mergeId int, configPath string) (*
 	return &info, nil
 }
 
+func (g *GitlabProvider) ListBranches(projectId int) ([]handlers.Branch, error) {
+	branches, _, err := g.client.Branches.ListBranches(projectId, &gitlab.ListBranchesOptions{})
+	if err != nil {
+		return nil, err
+	}
+
+	staleBranches := []handlers.Branch{}
+	for _, b := range branches {
+		if b.Default || b.Protected {
+			continue
+		}
+
+		staleBranches = append(staleBranches, handlers.Branch{Name: b.Name, LastUpdated: *b.Commit.CreatedAt})
+	}
+	return staleBranches, nil
+}
+
+func (g *GitlabProvider) DeleteBranch(projectId int, name string) error {
+	_, err := g.client.Branches.DeleteBranch(projectId, name)
+	return err
+}
+
 func New() handlers.RequestProvider {
 	var err error
 	var p GitlabProvider

handlers/provider.go

@@ -46,6 +46,8 @@ type RequestProvider interface {
 	LeaveComment(projectId, mergeId int, message string) error
 	GetMRInfo(projectId, mergeId int, path string) (*MrInfo, error)
 	UpdateFromMaster(projectId, mergeId int) error
+	ListBranches(projectId int) ([]Branch, error)
+	DeleteBranch(projectId int, name string) error
 }
 
 type Config struct {
@@ -55,14 +57,20 @@ type Config struct {
 	AllowFailingTests     bool     `yaml:"allow_failing_tests"`
 	TitleRegex            string   `yaml:"title_regex"`
 	AllowEmptyDescription bool     `yaml:"allow_empty_description"`
-	EnableGreetings       bool     `yaml:"greetings_enabled"`
-	GreetingsTemplate     string   `yaml:"greetings_template"`
-	AutoMasterMerge       bool     `yaml:"auto_master_merge"`
+	Greetings             struct {
+		Enabled  bool   `yaml:"enabled"`
+		Template string `yaml:"template"`
+	} `yaml:"greetings"`
+	AutoMasterMerge       bool `yaml:"auto_master_merge"`
+	StaleBranchesDeletion struct {
+		Enabled bool `yaml:"enabled"`
+		Days    int  `yaml:"days"`
+	} `yaml:"stale_branches_deletion"`
 }
 
 func New(providerName string) (*Request, error) {
-	providersMu.Lock()
-	defer providersMu.Unlock()
+	providersMu.RLock()
+	defer providersMu.RUnlock()
 
 	if _, ok := providers[providerName]; !ok {
 		return nil, &Error{text: "Provider can't be nil"}

handlers/request.go

@@ -64,9 +64,21 @@ func (r *Request) ParseConfig(content string) (*Config, error) {
 		AllowFailingTests:     true,
 		TitleRegex:            ".*",
 		AllowEmptyDescription: true,
-		EnableGreetings:       false,
-		GreetingsTemplate:     "Requirements:\n - Min approvals: {{ .MinApprovals }}\n - Title regex: {{ .TitleRegex }}\n\nOnce you've done, send **!merge** command and i will merge it!",
-		AutoMasterMerge:       false,
+		Greetings: struct {
+			Enabled  bool   `yaml:"enabled"`
+			Template string `yaml:"template"`
+		}{
+			Enabled:  false,
+			Template: "Requirements:\n - Min approvals: {{ .MinApprovals }}\n - Title regex: {{ .TitleRegex }}\n\nOnce you've done, send **!merge** command and i will merge it!",
+		},
+		AutoMasterMerge: false,
+		StaleBranchesDeletion: struct {
+			Enabled bool `yaml:"enabled"`
+			Days    int  `yaml:"days"`
+		}{
+			Enabled: false,
+			Days:    90,
+		},
 	}
 
 	if err := yaml.Unmarshal([]byte(content), mrConfig); err != nil {
@@ -84,11 +96,11 @@ func (r *Request) Greetings(projectId, id int) error {
 		return err
 	}
 
-	if !r.config.EnableGreetings {
+	if !r.config.Greetings.Enabled {
 		return nil
 	}
 
-	tmpl, err := template.New("greetings").Parse(r.config.GreetingsTemplate)
+	tmpl, err := template.New("greetings").Parse(r.config.Greetings.Template)
 	if err != nil {
 		return err
 	}
@@ -111,6 +123,10 @@ func (r *Request) Merge(projectId, id int) (bool, string, error) {
 		_ = r.provider.UpdateFromMaster(projectId, id)
 	}
 
+	if r.config.StaleBranchesDeletion.Enabled {
+		defer r.cleanStaleBranches(projectId)
+	}
+
 	if ok, text, err := r.IsValid(projectId, id); ok {
 		if err := r.provider.Merge(projectId, id, fmt.Sprintf("%s\nMerged by MergeApproveBot", r.info.Title)); err != nil {
 			return false, "", err

handlers/request_test.go

@@ -32,6 +32,14 @@ func (p *testProvider) Merge(projectId, id int, message string) error {
 	return p.err
 }
 
+func (p *testProvider) ListBranches(projectId int) ([]Branch, error) {
+	return nil, nil
+}
+
+func (p *testProvider) DeleteBranch(projectId int, name string) error {
+	return nil
+}
+
 func (p *testProvider) GetMRInfo(projectId, id int, path string) (*MrInfo, error) {
 	return &MrInfo{
 		Title:           p.title,

handlers/stalebranches.go

@@ -0,0 +1,33 @@
+package handlers
+
+import (
+	"log/slog"
+	"time"
+)
+
+type Branch struct {
+	Name        string
+	LastUpdated time.Time
+}
+
+func (r *Request) cleanStaleBranches(projectId int) {
+	candidates, err := r.provider.ListBranches(projectId)
+	if err != nil {
+		slog.Error("ListBranches returns error", "err", err)
+		return
+	}
+
+	days := r.config.StaleBranchesDeletion.Days
+	for _, b := range candidates {
+		now := time.Now()
+		span := now.Sub(b.LastUpdated)
+		if span > time.Duration(time.Duration(days)*24*time.Hour) {
+			// branch is stale
+			// delete branch
+			slog.Debug("branch info", "name", b.Name, "createdAt", b.LastUpdated.String())
+			if err := r.provider.DeleteBranch(projectId, b.Name); err != nil {
+				slog.Error("DeleteBranch returns error", "branch", b.Name, "err", err)
+			}
+		}
+	}
+}