Fix sync-tags handling of dependency tags

cmd/sync-tags/gomod.go

@@ -34,7 +34,7 @@ import (
 
 // updateGomodWithTaggedDependencies gets the dependencies at the given tag and fills go.mod and go.sum.
 // If anything is changed, it commits the changes. Returns true if go.mod changed.
-func updateGomodWithTaggedDependencies(tag string, depsRepo []string, semverTag bool) (bool, error) {
+func updateGomodWithTaggedDependencies(searchTag string, depsRepo []string, semverTag bool) (bool, error) {
 	found := map[string]bool{}
 	changed := false
 
@@ -55,12 +55,59 @@ func updateGomodWithTaggedDependencies(tag string, depsRepo []string, semverTag
 			return changed, fmt.Errorf("failed to get package at %s: %w", depPath, err)
 		}
 
-		commit, commitTime, err := localOrPublishedTaggedCommitHashAndTime(dr, tag)
+		commit, commitTime, err := localOrPublishedTaggedCommitHashAndTime(dr, searchTag)
 		if err != nil {
-			return changed, fmt.Errorf("failed to get tag %s for %q: %w", tag, depPkg, err)
+			return changed, fmt.Errorf("failed to get tag %s for %q: %w", searchTag, depPkg, err)
 		}
 		rev := commit.String()
-		pseudoVersionOrTag := fmt.Sprintf("v0.0.0-%s-%s", commitTime.UTC().Format("20060102150405"), rev[:12])
+
+		moduleMajor := uint64(0)
+		tag := ""
+		if semverTag {
+			iter, err := dr.Tags()
+			if err != nil {
+				return changed, fmt.Errorf("failed to get tags for repo %s: %w", dep, err)
+			}
+
+			var tags []string
+			err = iter.ForEach(func(ref *plumbing.Reference) error {
+				if tagObj, err := dr.TagObject(ref.Hash()); err == nil {
+					if tagObj.Target == commit && strings.HasPrefix(strings.TrimPrefix(ref.Name().Short(), "origin/"), "v") {
+						tags = append(tags, ref.Name().Short())
+					}
+				}
+
+				return nil
+			})
+			if err != nil {
+				return changed, fmt.Errorf("failed to find semver tag for given search tag: %w", err)
+			}
+			iter.Close()
+
+			if len(tags) == 0 {
+				return changed, fmt.Errorf("no semver tag found for given search tag %s", searchTag)
+			}
+
+			// pick the highest semver tag
+			semvers := make([]semver.Version, 0, len(tags))
+			for _, t := range tags {
+				sv, err := semver.Parse(strings.TrimPrefix(t, "v"))
+				if err != nil {
+					return changed, fmt.Errorf("failed to parse semver tag %s: %w", t, err)
+				}
+				semvers = append(semvers, sv)
+			}
+			semver.Sort(semvers)
+
+			latestSemver := semvers[len(semvers)-1]
+			moduleMajor = latestSemver.Major
+			if moduleMajor == 1 {
+				moduleMajor = 0
+			}
+			tag = fmt.Sprintf("v%s", latestSemver.String())
+		}
+
+		pseudoVersionOrTag := fmt.Sprintf("v%d.0.0-%s-%s", moduleMajor, commitTime.UTC().Format("20060102150405"), rev[:12])
 
 		// TODO(xmudrii): We are configured to always hit this case because we have --publish-semver-tags set to true,
 		// so pseudo-version is not important. At some point, it would be nice to fix this.
@@ -126,7 +173,7 @@ func updateGomodWithTaggedDependencies(tag string, depsRepo []string, semverTag
 	if err := tidyCommand.Run(); err != nil {
 		return changed, fmt.Errorf("unable to run go mod tidy: %w", err)
 	}
-	fmt.Printf("Completed running go mod tidy for %s.\n", tag)
+	fmt.Printf("Completed running go mod tidy for %s.\n", searchTag)
 
 	return changed, nil
 }

cmd/sync-tags/main.go

@@ -257,19 +257,24 @@ func main() {
 			}
 			rev := commit.String()
 
-			pseudoSemver, err := semver.Parse(strings.TrimPrefix(name, "v"))
+			// The Go mod cache is built upon the target tag name,
+			// not the source tag name, so we use generated tag name here.
+			// Only if it doesn't exist for some reason, we fall back to
+			// the original tag name.
+			pseudoSemverString := strings.TrimPrefix(semverTag, "v")
+			if pseudoSemverString == "" {
+				pseudoSemverString = strings.TrimPrefix(name, "v")
+			}
+			pseudoSemver, err := semver.Parse(pseudoSemverString)
 			if err != nil {
 				glog.Fatalf("error parsing pseudo-version: %v", err)
 			}
-
-			pseudoVersion := fmt.Sprintf("v0.0.0-%s-%s", commitTime.UTC().Format("20060102150405"), rev[:12])
-			if pseudoSemver.Major >= 2 {
-				if len(pseudoSemver.Pre) == 0 {
-					pseudoVersion = fmt.Sprintf("v%d.%d.%d-0.%s-%s", pseudoSemver.Major, pseudoSemver.Minor, pseudoSemver.Patch+1, commitTime.UTC().Format("20060102150405"), rev[:12])
-				} else {
-					pseudoVersion = fmt.Sprintf("v%s.0.%s-%s", strings.TrimPrefix(name, "v"), commitTime.UTC().Format("20060102150405"), rev[:12])
-				}
+			// Both v0 and v1 use v0 in pseudo-version.
+			moduleMajor := pseudoSemver.Major
+			if moduleMajor == 1 {
+				moduleMajor = 0
 			}
+			pseudoVersion := fmt.Sprintf("v%d.0.0-%s-%s", moduleMajor, commitTime.UTC().Format("20060102150405"), rev[:12])
 
 			fmt.Printf("Clearing cache for local tag %s.\n", pseudoVersion)
 			if err := cleanCacheForTag(pseudoVersion); err != nil {
@@ -346,11 +351,7 @@ func main() {
 			var changed bool
 			_, err = os.Stat("go.mod")
 			if err == nil {
-				if publishSemverTag {
-					changed = updateGoMod(semverTag, dependentRepos, true)
-				} else {
-					changed = updateGoMod(bName, dependentRepos, false)
-				}
+				changed = updateGoMod(bName, dependentRepos, publishSemverTag)
 			}
 
 			if changed {
@@ -538,11 +539,11 @@ func checkoutBranchTagCommit(r *gogit.Repository, bh plumbing.Hash, dependentRep
 	return wt
 }
 
-func updateGoMod(tag string, dependentRepos []string, publishSemverTags bool) bool {
-	fmt.Printf("Updating go.mod and go.sum to point to %s tag.\n", tag)
-	changed, err := updateGomodWithTaggedDependencies(tag, dependentRepos, publishSemverTags)
+func updateGoMod(searchTag string, dependentRepos []string, publishSemverTags bool) bool {
+	fmt.Printf("Updating go.mod and go.sum to point to %s tag.\n", searchTag)
+	changed, err := updateGomodWithTaggedDependencies(searchTag, dependentRepos, publishSemverTags)
 	if err != nil {
-		glog.Fatalf("Failed to update go.mod and go.sum for tag %s: %v", tag, err)
+		glog.Fatalf("Failed to update go.mod and go.sum for tag %s: %v", searchTag, err)
 	}
 	return changed
 }