Support for overriding base branch names (#64)

Author: nirnanaaa

README.md

@@ -265,7 +265,7 @@ Passing the `--branch-name` (`-b`) flag is required when running `git-xargs`. If
 
 ## Default repository branch
 
-Any pull requests opened will be opened against the repository's default branch (whether that's `main`, or `master` or something else).
+Any pull requests opened will be opened against the repository's default branch (whether that's `main`, or `master` or something else). You can supply an additional `--base-branch-name` flag to change the target for your pull requests. Be aware that this will override the base branch name for **ALL** targeted repositories.
 
 ## Git file staging behavior
 

cmd/git-xargs.go

@@ -25,6 +25,7 @@ func parseGitXargsConfig(c *cli.Context) (*config.GitXargsConfig, error) {
 	config.SkipPullRequests = c.Bool("skip-pull-requests")
 	config.SkipArchivedRepos = c.Bool("skip-archived-repos")
 	config.BranchName = c.String("branch-name")
+	config.BaseBranchName = c.String("base-branch-name")
 	config.CommitMessage = c.String("commit-message")
 	config.PullRequestTitle = c.String("pull-request-title")
 	config.PullRequestDescription = c.String("pull-request-description")

common/common.go

@@ -12,6 +12,7 @@ const (
 	ReposFileFlagName              = "repos"
 	CommitMessageFlagName          = "commit-message"
 	BranchFlagName                 = "branch-name"
+	BaseBranchFlagName             = "base-branch-name"
 	PullRequestTitleFlagName       = "pull-request-title"
 	PullRequestDescriptionFlagName = "pull-request-description"
 	MaxConcurrentReposFlagName     = "max-concurrent-repos"
@@ -54,6 +55,10 @@ var (
 		Name:  BranchFlagName,
 		Usage: "The name of the branch on which changes will be made",
 	}
+	GenericBaseBranchFlag = cli.StringFlag{
+		Name:  BaseBranchFlagName,
+		Usage: "The base branch that changes should be merged into",
+	}
 	GenericCommitMessageFlag = cli.StringFlag{
 		Name:  CommitMessageFlagName,
 		Usage: "The commit message to use when creating commits from changes introduced by your command or script",

config/config.go

@@ -18,6 +18,7 @@ type GitXargsConfig struct {
 	SkipArchivedRepos      bool
 	MaxConcurrentRepos     int
 	BranchName             string
+	BaseBranchName         string
 	CommitMessage          string
 	PullRequestTitle       string
 	PullRequestDescription string
@@ -40,6 +41,7 @@ func NewGitXargsConfig() *GitXargsConfig {
 		SkipArchivedRepos:      false,
 		MaxConcurrentRepos:     0,
 		BranchName:             "",
+		BaseBranchName:         "",
 		CommitMessage:          common.DefaultCommitMessage,
 		PullRequestTitle:       common.DefaultPullRequestTitle,
 		PullRequestDescription: common.DefaultPullRequestDescription,

main.go

@@ -69,6 +69,7 @@ func setupApp() *cli.App {
 		common.GenericRepoFlag,
 		common.GenericRepoFileFlag,
 		common.GenericBranchFlag,
+		common.GenericBaseBranchFlag,
 		common.GenericCommitMessageFlag,
 		common.GenericPullRequestTitleFlag,
 		common.GenericPullRequestDescriptionFlag,

repository/repo-operations.go

@@ -7,6 +7,7 @@ import (
 	"io/ioutil"
 	"os"
 	"os/exec"
+	"strings"
 
 	"github.com/go-git/go-git/v5"
 	"github.com/go-git/go-git/v5/plumbing"
@@ -390,8 +391,11 @@ func openPullRequest(config *config.GitXargsConfig, repo *github.Repository, bra
 		}).Debug("--dry-run and / or --skip-pull-requests is set to true, so skipping opening a pull request!")
 		return nil
 	}
+	repoDefaultBranch := config.BaseBranchName
+	if repoDefaultBranch == "" {
+		repoDefaultBranch = repo.GetDefaultBranch()
+	}
 
-	repoDefaultBranch := repo.GetDefaultBranch()
 	pullRequestAlreadyExists, err := pullRequestAlreadyExistsForBranch(config, repo, branch, repoDefaultBranch)
 
 	if err != nil {
@@ -449,31 +453,41 @@ func openPullRequest(config *config.GitXargsConfig, repo *github.Repository, bra
 	pr, resp, err := config.GithubClient.PullRequests.Create(context.Background(), *repo.GetOwner().Login, repo.GetName(), newPR)
 
 	prErrorMessage := "Error opening pull request"
-	prDraftModeNotSupported := false
 
+	// Github's API will return HTTP status code 422 for several different errors
+	// Currently, there are two such errors that git-xargs is concerned with:
+	// 1. User passes the --draft flag, but the targeted repo does not support draft pull requests
+	// 2. User passes the --base-branch-name flag, specifying a branch that does not exist in the repo
 	if err != nil {
 		if resp.StatusCode == 422 {
-			// Update the error to be more RepoDoesntSupportDraftPullRequestsErra Draft PR
-			prErrorMessage = "Error opening pull request: draft PRs not supported for this repo. See https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/proposing-changes-to-your-work-with-pull-requests/about-pull-requests#draft-pull-requests"
-			prDraftModeNotSupported = true
+			switch {
+			case strings.Contains(err.Error(), "Draft pull requests are not supported"):
+				prErrorMessage = "Error opening pull request: draft PRs not supported for this repo. See https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/proposing-changes-to-your-work-with-pull-requests/about-pull-requests#draft-pull-requests"
+				config.Stats.TrackSingle(stats.RepoDoesntSupportDraftPullRequestsErr, repo)
+
+			case strings.Contains(err.Error(), "Field:base Code:invalid"):
+				prErrorMessage = fmt.Sprintf("Error opening pull request: Base branch name: %s is invalid", config.BaseBranchName)
+				config.Stats.TrackSingle(stats.BaseBranchTargetInvalidErr, repo)
+
+			default:
+				config.Stats.TrackSingle(stats.PullRequestOpenErr, repo)
+			}
 		}
 
+		// If the Github reponse's status code is not 422, fallback to logging and tracking a generic pull request error
+		config.Stats.TrackSingle(stats.PullRequestOpenErr, repo)
+
 		logger.WithFields(logrus.Fields{
 			"Error": err,
 			"Head":  branch,
 			"Base":  repoDefaultBranch,
 			"Body":  descriptionToUse,
 		}).Debug(prErrorMessage)
 
-		// Track pull request open failure
-		if prDraftModeNotSupported {
-			config.Stats.TrackSingle(stats.RepoDoesntSupportDraftPullRequestsErr, repo)
-		} else {
-			config.Stats.TrackSingle(stats.PullRequestOpenErr, repo)
-		}
 		return errors.WithStackTrace(err)
 	}
 
+	// There was no error opening the pull request
 	logger.WithFields(logrus.Fields{
 		"Pull Request URL": pr.GetHTMLURL(),
 	}).Debug("Successfully opened pull request")

stats/stats.go

@@ -70,6 +70,8 @@ const (
 	RepoFlagSuppliedRepoMalformed types.Event = "repo-flag-supplied-repo-malformed"
 	// RepoDoesntSupportDraftPullRequestsErr denotes a repo that is incompatible with the submitted pull request configuration
 	RepoDoesntSupportDraftPullRequestsErr types.Event = "repo-not-compatible-with-pull-config"
+	// BaseBranchTargetInvalidErr denotes a repo that does not have the base branch specified by the user
+	BaseBranchTargetInvalidErr types.Event = "base-branch-target-invalid"
 )
 
 var allEvents = []types.AnnotatedEvent{
@@ -100,6 +102,7 @@ var allEvents = []types.AnnotatedEvent{
 	{Event: BranchRemoteDidntExistYet, Description: "Repos whose specified branches did not exist on the remote, and so were first created locally"},
 	{Event: RepoFlagSuppliedRepoMalformed, Description: "Repos passed via the --repo flag that were malformed (missing their Github org prefix?) and therefore unprocessable"},
 	{Event: RepoDoesntSupportDraftPullRequestsErr, Description: "Repos that do not support Draft PRs (--draft flag was passed)"},
+	{Event: BaseBranchTargetInvalidErr, Description: "Repos that did not have the branch specified by --base-branch-name"},
 }
 
 // RunStats will be a stats-tracker class that keeps score of which repos were touched, which were considered for update, which had branches made, PRs made, which were missing workflows or contexts, or had out of date workflows syntax values, etc