separate out tagging function

rcpr.go

@@ -99,6 +99,9 @@ func newRcpr(ctx context.Context, c *commander) (*rcpr, error) {
 }
 
 func isRcpr(pr *github.PullRequest) bool {
+	if pr == nil {
+		return false
+	}
 	for _, label := range pr.Labels {
 		if label.GetName() == autoLableName {
 			return true
@@ -177,87 +180,13 @@ func Run(ctx context.Context, argv []string, outStream, errStream io.Writer) err
 		rp.c.Git("config", "--local", "user.name", gitUser)
 	}
 
-	{
-		// tag and exit if the HEAD is the merged rcpr
-		commitish, _, err := rp.c.GitE("rev-parse", "HEAD")
-		if err != nil {
-			return err
-		}
-		pulls, _, err := rp.gh.PullRequests.ListPullRequestsWithCommit(
-			ctx, rp.owner, rp.repo, commitish, nil)
+	// If the latest commit is a merge commit of the pull request by rcpr,
+	// tag the semver to the commit and create a release and exit.
+	if pr, err := rp.latestPullRequest(ctx); err != nil || isRcpr(pr) {
 		if err != nil {
 			return err
 		}
-		if len(pulls) > 0 && isRcpr(pulls[0]) {
-			var vfile string
-			if rp.cfg.versionFile == nil {
-				rp.c.Git("checkout", "HEAD~")
-				vfile, err = detectVersionFile(".", currVer)
-				if err != nil {
-					return err
-				}
-				rp.c.Git("checkout", releaseBranch)
-			} else {
-				vfile = rp.cfg.versionFile.String()
-			}
-
-			var nextTag string
-			if vfile != "" {
-				nextVer, err := retrieveVersionFromFile(vfile, currVer.vPrefix)
-				if err != nil {
-					return err
-				}
-				nextTag = nextVer.Tag()
-			} else {
-				nextTag = guessNextSemver(currVer, pulls[0]).Tag()
-			}
-			previousTag := &latestSemverTag
-			if *previousTag == "" {
-				previousTag = nil
-			}
-
-			// To avoid putting pull requests created by rcpr itself in the release notes,
-			// we generate release notes in advance.
-			// Get the previous commitish to avoid picking up the merge of the pull
-			// request made by rcpr.
-			targetCommitish, _, err := rp.c.GitE("rev-parse", "HEAD~")
-			if err != nil {
-				return nil
-			}
-			releases, _, err := rp.gh.Repositories.GenerateReleaseNotes(
-				ctx, rp.owner, rp.repo, &github.GenerateNotesOptions{
-					TagName:         nextTag,
-					PreviousTagName: previousTag,
-					TargetCommitish: &targetCommitish,
-				})
-			if err != nil {
-				return err
-			}
-
-			rp.c.Git("tag", nextTag)
-			if rp.c.err != nil {
-				return rp.c.err
-			}
-			_, _, err = rp.c.GitE("push", "--tags")
-			if err != nil {
-				return err
-			}
-
-			// Don't use GenerateReleaseNote flag and use pre generated one
-			_, _, err = rp.gh.Repositories.CreateRelease(
-				ctx, rp.owner, rp.repo, &github.RepositoryRelease{
-					TagName:         &nextTag,
-					TargetCommitish: &releaseBranch,
-					Name:            &releases.Name,
-					Body:            &releases.Body,
-					// I want to make it as a draft release by default, but it is difficult to get a draft release
-					// from another tool via API, and there is no tool supports it, so I will make it as a normal
-					// release. In the future, there may be an option to create it as a Draft, or conversely,
-					// an option not to create a release.
-					// Draft: github.Bool(true),
-				})
-			return err
-		}
+		return rp.tagRelease(ctx, pr, currVer, latestSemverTag)
 	}
 
 	rcBranch := fmt.Sprintf("rcpr-from-%s", currVer.Tag())

tag.go

@@ -0,0 +1,99 @@
+package rcpr
+
+import (
+	"context"
+
+	"github.com/google/go-github/v45/github"
+)
+
+func (rp *rcpr) latestPullRequest(ctx context.Context) (*github.PullRequest, error) {
+	// tag and exit if the HEAD is the merged rcpr
+	commitish, _, err := rp.c.GitE("rev-parse", "HEAD")
+	if err != nil {
+		return nil, err
+	}
+	pulls, _, err := rp.gh.PullRequests.ListPullRequestsWithCommit(
+		ctx, rp.owner, rp.repo, commitish, nil)
+	if err != nil {
+		return nil, err
+	}
+	if len(pulls) == 0 {
+		return nil, nil
+	}
+	return pulls[0], nil
+}
+
+func (rp *rcpr) tagRelease(ctx context.Context, pr *github.PullRequest, currVer *semv, latestSemverTag string) error {
+	var (
+		vfile string
+		err   error
+	)
+	releaseBranch := rp.cfg.releaseBranch.String()
+	if rp.cfg.versionFile == nil {
+		rp.c.Git("checkout", "HEAD~")
+		vfile, err = detectVersionFile(".", currVer)
+		if err != nil {
+			return err
+		}
+		rp.c.Git("checkout", releaseBranch)
+	} else {
+		vfile = rp.cfg.versionFile.String()
+	}
+
+	var nextTag string
+	if vfile != "" {
+		nextVer, err := retrieveVersionFromFile(vfile, currVer.vPrefix)
+		if err != nil {
+			return err
+		}
+		nextTag = nextVer.Tag()
+	} else {
+		nextTag = guessNextSemver(currVer, pr).Tag()
+	}
+	previousTag := &latestSemverTag
+	if *previousTag == "" {
+		previousTag = nil
+	}
+
+	// To avoid putting pull requests created by rcpr itself in the release notes,
+	// we generate release notes in advance.
+	// Get the previous commitish to avoid picking up the merge of the pull
+	// request made by rcpr.
+	targetCommitish, _, err := rp.c.GitE("rev-parse", "HEAD~")
+	if err != nil {
+		return nil
+	}
+	releases, _, err := rp.gh.Repositories.GenerateReleaseNotes(
+		ctx, rp.owner, rp.repo, &github.GenerateNotesOptions{
+			TagName:         nextTag,
+			PreviousTagName: previousTag,
+			TargetCommitish: &targetCommitish,
+		})
+	if err != nil {
+		return err
+	}
+
+	rp.c.Git("tag", nextTag)
+	if rp.c.err != nil {
+		return rp.c.err
+	}
+	_, _, err = rp.c.GitE("push", "--tags")
+	if err != nil {
+		return err
+	}
+
+	// Don't use GenerateReleaseNote flag and use pre generated one
+	_, _, err = rp.gh.Repositories.CreateRelease(
+		ctx, rp.owner, rp.repo, &github.RepositoryRelease{
+			TagName:         &nextTag,
+			TargetCommitish: &releaseBranch,
+			Name:            &releases.Name,
+			Body:            &releases.Body,
+			// I want to make it as a draft release by default, but it is difficult to get a draft release
+			// from another tool via API, and there is no tool supports it, so I will make it as a normal
+			// release. In the future, there may be an option to create it as a Draft, or conversely,
+			// an option not to create a release.
+			// Draft: github.Bool(true),
+		})
+	return err
+}