Don't try to open PR if one is already open (#34)

* Don't try to open PR if one is already open

* Fix filtering on head branch

* Switch to GetOwner()

* Track skipped pull requests

Author: brikis98

auth/auth.go

@@ -14,6 +14,7 @@ import (
 // The go-github package satisfies this PullRequest service's interface in production
 type githubPullRequestService interface {
 	Create(ctx context.Context, owner string, name string, pr *github.NewPullRequest) (*github.PullRequest, *github.Response, error)
+	List(ctx context.Context, owner string, repo string, opts *github.PullRequestListOptions) ([]*github.PullRequest, *github.Response, error)
 }
 
 // The go-github package satisfies this Repositories service's interface in production

mocks/mocks.go

@@ -53,6 +53,10 @@ func (m mockGithubPullRequestService) Create(ctx context.Context, owner, name st
 	return m.PullRequest, m.Response, nil
 }
 
+func (m mockGithubPullRequestService) List(ctx context.Context, owner string, repo string, opts *github.PullRequestListOptions) ([]*github.PullRequest, *github.Response, error) {
+	return []*github.PullRequest{m.PullRequest}, m.Response, nil
+}
+
 // This mocks the Repositories service in go-github that is used in production to call the associated Github endpoint
 type mockGithubRepositoriesService struct {
 	Repository   *github.Repository

repository/process.go

@@ -78,22 +78,9 @@ func processRepo(config *config.GitXargsConfig, repo *github.Repository) error {
 		return commandErr
 	}
 
-	// Commit any untracked files, modified or deleted files that resulted from script execution
-	commitErr := commitLocalChanges(config, repositoryDir, worktree, repo, localRepository)
-	if commitErr != nil {
-		return commitErr
-	}
-
-	// Push the local branch containing all of our changes from executing the supplied command
-	pushBranchErr := pushLocalBranch(config, repo, localRepository)
-	if pushBranchErr != nil {
-		return pushBranchErr
-	}
-
-	// Open a pull request on Github, of the recently pushed branch against the repository default branch
-	openPullRequestErr := openPullRequest(config, repo, branchName.String())
-	if openPullRequestErr != nil {
-		return openPullRequestErr
+	// Commit and push the changes to Git and open a PR
+	if err := updateRepo(config, repositoryDir, worktree, repo, localRepository, branchName.String()); err != nil {
+		return err
 	}
 
 	return nil

repository/repo-operations.go

@@ -210,9 +210,10 @@ func checkoutLocalBranch(config *config.GitXargsConfig, ref *plumbing.Reference,
 	return branchName, nil
 }
 
-// commitLocalChanges will check for any changes in worktree as a result of script execution, and if any are present,
-// add any untracked, deleted or modified files and create a commit using the supplied or default commit message.
-func commitLocalChanges(config *config.GitXargsConfig, repositoryDir string, worktree *git.Worktree, remoteRepository *github.Repository, localRepository *git.Repository) error {
+// updateRepo will check for any changes in worktree as a result of script execution, and if any are present,
+// add any untracked, deleted or modified files, create a commit using the supplied or default commit message,
+// push the code to the remote repo, and open a pull request.
+func updateRepo(config *config.GitXargsConfig, repositoryDir string, worktree *git.Worktree, remoteRepository *github.Repository, localRepository *git.Repository, branchName string) error {
 	logger := logging.GetLogger("git-xargs")
 
 	status, statusErr := worktree.Status()
@@ -241,6 +242,32 @@ func commitLocalChanges(config *config.GitXargsConfig, repositoryDir string, wor
 		return nil
 	}
 
+	// Commit any untracked files, modified or deleted files that resulted from script execution
+	commitErr := commitLocalChanges(status, config, repositoryDir, worktree, remoteRepository, localRepository)
+	if commitErr != nil {
+		return commitErr
+	}
+
+	// Push the local branch containing all of our changes from executing the supplied command
+	pushBranchErr := pushLocalBranch(config, remoteRepository, localRepository)
+	if pushBranchErr != nil {
+		return pushBranchErr
+	}
+
+	// Open a pull request on Github, of the recently pushed branch against the repository default branch
+	openPullRequestErr := openPullRequest(config, remoteRepository, branchName)
+	if openPullRequestErr != nil {
+		return openPullRequestErr
+	}
+
+	return nil
+}
+
+// commitLocalChanges will check for any changes in worktree as a result of script execution, and if any are present,
+// add any untracked, deleted or modified files and create a commit using the supplied or default commit message.
+func commitLocalChanges(status git.Status, config *config.GitXargsConfig, repositoryDir string, worktree *git.Worktree, remoteRepository *github.Repository, localRepository *git.Repository) error {
+	logger := logging.GetLogger("git-xargs")
+
 	// If there are changes, we need to stage, add and commit them
 	logger.WithFields(logrus.Fields{
 		"Repo": remoteRepository.GetName(),
@@ -343,7 +370,6 @@ func pushLocalBranch(config *config.GitXargsConfig, remoteRepository *github.Rep
 // Attempt to open a pull request via the Github API, of the supplied branch specific to this tool, against the main
 // branch for the remote origin
 func openPullRequest(config *config.GitXargsConfig, repo *github.Repository, branch string) error {
-
 	logger := logging.GetLogger("git-xargs")
 
 	if config.DryRun || config.SkipPullRequests {
@@ -353,6 +379,33 @@ func openPullRequest(config *config.GitXargsConfig, repo *github.Repository, bra
 		return nil
 	}
 
+	repoDefaultBranch := repo.GetDefaultBranch()
+	pullRequestAlreadyExists, err := pullRequestAlreadyExistsForBranch(config, repo, branch, repoDefaultBranch)
+
+	if err != nil {
+		logger.WithFields(logrus.Fields{
+			"Error": err,
+			"Head":  branch,
+			"Base":  repoDefaultBranch,
+		}).Debug("Error listing pull requests")
+
+		// Track pull request open failure
+		config.Stats.TrackSingle(stats.PullRequestOpenErr, repo)
+		return errors.WithStackTrace(err)
+	}
+
+	if pullRequestAlreadyExists {
+		logger.WithFields(logrus.Fields{
+			"Repo": repo.GetName(),
+			"Head": branch,
+			"Base": repoDefaultBranch,
+		}).Debug("Pull request already exists for this branch, so skipping opening a pull request!")
+
+		// Track that we skipped opening a pull request
+		config.Stats.TrackSingle(stats.PullRequestAlreadyExists, repo)
+		return nil
+	}
+
 	// If the user only supplies a commit message, use that for both the pull request title and descriptions,
 	// unless they are provided separately
 	titleToUse := config.PullRequestTitle
@@ -370,8 +423,6 @@ func openPullRequest(config *config.GitXargsConfig, repo *github.Repository, bra
 		}
 	}
 
-	repoDefaultBranch := repo.GetDefaultBranch()
-
 	// Configure pull request options that the Github client accepts when making calls to open new pull requests
 	newPR := &github.NewPullRequest{
 		Title:               github.String(titleToUse),
@@ -405,3 +456,20 @@ func openPullRequest(config *config.GitXargsConfig, repo *github.Repository, bra
 	config.Stats.TrackPullRequest(repo.GetName(), pr.GetHTMLURL())
 	return nil
 }
+
+// Returns true if a pull request already exists in the given repo for the given branch
+func pullRequestAlreadyExistsForBranch(config *config.GitXargsConfig, repo *github.Repository, branch string, repoDefaultBranch string) (bool, error) {
+	opts := &github.PullRequestListOptions{
+		// Filter pulls by head user or head organization and branch name in the format of user:ref-name or organization:ref-name
+		// https://docs.github.com/en/rest/reference/pulls#list-pull-requests
+		Head: fmt.Sprintf("%s:%s", *repo.GetOwner().Login, branch),
+		Base: repoDefaultBranch,
+	}
+
+	prs, _, err := config.GithubClient.PullRequests.List(context.Background(), *repo.GetOwner().Login, repo.GetName(), opts)
+	if err != nil {
+		return false, errors.WithStackTrace(err)
+	}
+
+	return len(prs) > 0, nil
+}

stats/stats.go

@@ -54,6 +54,8 @@ const (
 	RepoNotExists types.Event = "repo-not-exists"
 	// PullRequestOpenErr denotes a repo whose pull request containing config changes could not be made successfully
 	PullRequestOpenErr types.Event = "pull-request-open-error"
+	// PullRequestAlreadyExists denotes a repo where the pull request already exists for the requested branch, so we didn't open a new one
+	PullRequestAlreadyExists types.Event = "pull-request-already-exists"
 	// CommitsMadeDirectlyToBranch denotes a repo whose local worktree changes were committed directly to the specified branch because the --skip-pull-requests flag was passed
 	CommitsMadeDirectlyToBranch types.Event = "commits-made-directly-to-branch"
 	//DirectCommitsPushedToRemoteBranch denotes a repo whose changes were pushed to the remote specified branch because the --skip-pull-requests flag was passed
@@ -84,6 +86,7 @@ var allEvents = []types.AnnotatedEvent{
 	{Event: PushBranchSkipped, Description: "Repos whose local branch was not pushed because the --dry-run flag was set"},
 	{Event: RepoNotExists, Description: "Repos that were supplied by user but don't exist (404'd) via Github API"},
 	{Event: PullRequestOpenErr, Description: "Repos against which pull requests failed to be opened"},
+	{Event: PullRequestAlreadyExists, Description: "Repos where opening a pull request was skipped because a pull request was already open"},
 	{Event: CommitsMadeDirectlyToBranch, Description: "Repos whose local changes were committed directly to the specified branch because --skip-pull-requests was passed"},
 	{Event: DirectCommitsPushedToRemoteBranch, Description: "Repos whose changes were pushed directly to the remote branch because --skip-pull-requests was passed"},
 	{Event: BranchRemotePullFailed, Description: "Repos whose remote branches could not be successfully pulled"},