fix: improves error trapping when there are no changes since start tag.

changelog/changelog.go

@@ -183,10 +183,13 @@ func GetUpdatedChangelog(
  beforeTag string,
  afterTag string,
  unique bool,
-) (metadata vcs.ReleaseMetadata, updatedChangelog string) {
+) (metadata vcs.ReleaseMetadata, updatedChangelog string, err error) {
  commits, err := vcs.FetchCommitsByTag(config, repoPath, beforeTag, afterTag, unique)
  if err != nil {
- panic(fmt.Errorf("failed to fetch commit messages from repo: %s: %v", repoPath, err))
+ return vcs.ReleaseMetadata{}, "", fmt.Errorf("failed to fetch commit messages from repo: %s: %v", repoPath, err)
+ }
+ if len(*commits) == 0 {
+ return vcs.ReleaseMetadata{}, "", fmt.Errorf("no changes since start tag")
  }
 
  currentVersion, vPrefix := semver.GetCurrentVersion(repoPath, orderBy)
@@ -229,7 +232,7 @@ func GetUpdatedChangelog(
  Sha: sha,
  VPrefix: vPrefix,
  }
- return metadata, output
+ return metadata, output, nil
 }
 
 // InitChangelog creates a new changelog file with a placeholder entry.
@@ -250,7 +253,11 @@ func InitChangelog(
  return "", fmt.Errorf("failed to get latest tag: %v", err)
  }
 
- _, updated := GetUpdatedChangelog(config, changelogFile, orderBy, repoPath, latestTag, "", unique)
+ _, updated, err := GetUpdatedChangelog(config, changelogFile, orderBy, repoPath, latestTag, "", unique)
+ if err != nil {
+ return "", fmt.Errorf("failed to get updated changelog: %v", err)
+ }
+
  err = WriteChangelog(changelogFile, updated)
  if err != nil {
  return "", fmt.Errorf("failed to write to initialised changelog: %s: %v", changelogFile, err)

changelog/changelog_test.go

@@ -17,7 +17,12 @@ limitations under the License.
 package changelog
 
 import (
+ "github.com/go-git/go-git/v5"
+ "github.com/go-git/go-git/v5/plumbing/object"
+ "github.com/release-tools/since/cfg"
  "github.com/release-tools/since/vcs"
+ "os"
+ "path"
  "reflect"
  "testing"
  "time"
@@ -153,3 +158,132 @@ func TestSplitIntoSections(t *testing.T) {
  })
  }
 }
+
+func TestGetUpdatedChangelog(t *testing.T) {
+ repoDir := createTestRepo(t)
+
+ type args struct {
+ config cfg.SinceConfig
+ changelogFile string
+ orderBy vcs.TagOrderBy
+ repoPath string
+ beforeTag string
+ afterTag string
+ unique bool
+ }
+ tests := []struct {
+ name string
+ args args
+ wantMetadata vcs.ReleaseMetadata
+ wantUpdatedChangelog string
+ wantErr bool
+ errMessage string
+ }{
+ {
+ name: "no changes",
+ args: args{
+ orderBy: vcs.TagOrderSemver,
+ repoPath: repoDir,
+ afterTag: "0.1.0",
+ },
+ wantMetadata: vcs.ReleaseMetadata{},
+ wantUpdatedChangelog: "",
+ wantErr: true,
+ errMessage: "no changes since start tag",
+ },
+ }
+ for _, tt := range tests {
+ t.Run(tt.name, func(t *testing.T) {
+ gotMetadata, gotUpdatedChangelog, err := GetUpdatedChangelog(tt.args.config, tt.args.changelogFile, tt.args.orderBy, tt.args.repoPath, tt.args.beforeTag, tt.args.afterTag, tt.args.unique)
+ if (err != nil) != tt.wantErr {
+ t.Errorf("GetUpdatedChangelog() error = %v, wantErr %v", err, tt.wantErr)
+ return
+ }
+ if err != nil && tt.wantErr && tt.errMessage != err.Error() {
+ t.Errorf("GetUpdatedChangelog() error message = '%v', want '%v'", err.Error(), tt.errMessage)
+ return
+ }
+ if !reflect.DeepEqual(gotMetadata, tt.wantMetadata) {
+ t.Errorf("GetUpdatedChangelog() gotMetadata = %v, want %v", gotMetadata, tt.wantMetadata)
+ }
+ if gotUpdatedChangelog != tt.wantUpdatedChangelog {
+ t.Errorf("GetUpdatedChangelog() gotUpdatedChangelog = %v, want %v", gotUpdatedChangelog, tt.wantUpdatedChangelog)
+ }
+ })
+ }
+}
+
+// createTestRepo creates a test repo with two tags:
+// 0.0.1 and 0.1.0
+// The first tag is created 10 seconds before the second tag.
+func createTestRepo(t *testing.T) string {
+ repoDir := t.TempDir()
+ t.Logf("created repo dir: %s", repoDir)
+
+ repoPathToReadme := path.Join(repoDir, "README.md")
+ readme, err := os.Create(repoPathToReadme)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ repo, err := git.PlainInit(repoDir, false)
+ if err != nil {
+ t.Fatal(err)
+ }
+ w, err := repo.Worktree()
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ _, err = readme.WriteString("first update")
+ if err != nil {
+ t.Fatal(err)
+ }
+ _, err = w.Add("README.md")
+ if err != nil {
+ t.Fatal(err)
+ }
+ c1sig := &object.Signature{
+ Name: "user",
+ Email: "user@example.com",
+ When: time.UnixMilli(time.Now().UnixMilli() - 10000),
+ }
+ c1, err := w.Commit("first update", &git.CommitOptions{
+ Author: c1sig,
+ Committer: c1sig,
+ })
+ if err != nil {
+ t.Fatal(err)
+ }
+ _, err = repo.CreateTag("0.0.1", c1, nil)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ _, err = readme.WriteString("second update")
+ if err != nil {
+ t.Fatal(err)
+ }
+ _, err = w.Add("README.md")
+ if err != nil {
+ t.Fatal(err)
+ }
+ c2Sig := &object.Signature{
+ Name: "user",
+ Email: "user@example.com",
+ When: time.Now(),
+ }
+ c2, err := w.Commit("second update", &git.CommitOptions{
+ Author: c2Sig,
+ Committer: c2Sig,
+ })
+ if err != nil {
+ t.Fatal(err)
+ }
+ _, err = repo.CreateTag("0.1.0", c2, nil)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ return repoDir
+}