fix: check empty commit-msg prior to parsing (#118)

Signed-off-by: Don Bowman <[email protected]>

internal/policy/commit/commit.go

@@ -104,15 +104,20 @@ func (c *Commit) Compliance(options *policy.Options) (report policy.Report) {
 		ValidateGPGSign(&report, g)
 	}
 
-	word := firstWord(msg)
+	var word string
+	if word, err = firstWord(msg, &report); err != nil {
+		return
+	}
 
 	if c.Conventional != nil {
 		groups := parseHeader(msg)
 		if len(groups) != 6 {
 			report.Errors = append(report.Errors, errors.Errorf("Invalid conventional commits format: %s", msg))
 			return
 		}
-		word = firstWord(groups[4])
+		if word, err = firstWord(groups[4], &report); err != nil {
+			return
+		}
 
 		ValidateType(&report, groups, c.Conventional.Types)
 		ValidateScope(&report, groups, c.Conventional.Scopes)
@@ -209,10 +214,17 @@ func ValidateDescription(report *policy.Report, groups []string) {
 	report.Errors = append(report.Errors, errors.Errorf("Invalid description: %s", groups[4]))
 }
 
-func firstWord(msg string) string {
-	header := strings.Split(strings.TrimPrefix(msg, "\n"), "\n")[0]
-	groups := FirstWordRegex.FindStringSubmatch(header)
-	return groups[0]
+func firstWord(msg string, report *policy.Report) (string, error) {
+	var header string
+	var groups []string
+	if header = strings.Split(strings.TrimPrefix(msg, "\n"), "\n")[0]; header == "" {
+		report.Errors = append(report.Errors, errors.Errorf("Invalid conventional commits (empty)"))
+		return "", errors.Errorf("Invalid msg: %s", msg)
+	}
+	if groups = FirstWordRegex.FindStringSubmatch(header); groups == nil {
+		return "", errors.Errorf("Invalid msg: %s", msg)
+	}
+	return groups[0], nil
 }
 
 func parseHeader(msg string) []string {

internal/policy/commit/commit_test.go

@@ -75,6 +75,33 @@ func TestInvalidConventionalCommitPolicy(t *testing.T) {
 	}
 }
 
+func TestEmptyConventionalCommitPolicy(t *testing.T) {
+	dir, err := ioutil.TempDir("", "test")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer RemoveAll(dir)
+	err = os.Chdir(dir)
+	if err != nil {
+		t.Error(err)
+	}
+	err = initRepo()
+	if err != nil {
+		t.Error(err)
+	}
+	err = createEmptyCommit()
+	if err != nil {
+		t.Error(err)
+	}
+	report, err := runCompliance()
+	if err != nil {
+		t.Error(err)
+	}
+	if report.Valid() {
+		t.Error("Report is valid with invalid conventional commit")
+	}
+}
+
 func runCompliance() (*policy.Report, error) {
 	c := &Commit{
 		Conventional: &Conventional{
@@ -113,3 +140,9 @@ func createInvalidCommit() error {
 
 	return err
 }
+
+func createEmptyCommit() error {
+	_, err := exec.Command("git", "-c", "user.name='test'", "-c", "user.email='[email protected]'", "commit", "--allow-empty-message", "-m", "").Output()
+
+	return err
+}