semver parsing fails pipeline step

cmd/drone-docker/main.go

@@ -298,10 +298,15 @@ func run(c *cli.Context) error {
 			c.String("commit.ref"),
 			c.String("repo.branch"),
 		) {
-			plugin.Build.Tags = docker.DefaultTagSuffix(
+			tag, err := docker.DefaultTagSuffix(
 				c.String("commit.ref"),
 				c.String("tags.suffix"),
 			)
+			if err != nil {
+				logrus.Printf("cannot build docker image for %s, invalid semantic version", c.String("commit.ref"))
+				return err
+			}
+			plugin.Build.Tags = tag
 		} else {
 			logrus.Printf("skipping automated docker build for %s", c.String("commit.ref"))
 			return nil

tags.go

@@ -9,10 +9,13 @@ import (
 
 // DefaultTagSuffix returns a set of default suggested tags
 // based on the commit ref with an attached suffix.
-func DefaultTagSuffix(ref, suffix string) []string {
+func DefaultTagSuffix(ref, suffix string) ([]string, error) {
-	tags := DefaultTags(ref)
+	tags, err := DefaultTags(ref)
+	if err != nil {
+		return nil, err
+	}
 	if len(suffix) == 0 {
-		return tags
+		return tags, nil
 	}
 	for i, tag := range tags {
 		if tag == "latest" {
@@ -21,7 +24,7 @@ func DefaultTagSuffix(ref, suffix string) []string {
 			tags[i] = fmt.Sprintf("%s-%s", tag, suffix)
 		}
 	}
-	return tags
+	return tags, nil
 }
 
 func splitOff(input string, delim string) string {
@@ -36,19 +39,19 @@ func splitOff(input string, delim string) string {
 
 // DefaultTags returns a set of default suggested tags based on
 // the commit ref.
-func DefaultTags(ref string) []string {
+func DefaultTags(ref string) ([]string, error) {
 	if !strings.HasPrefix(ref, "refs/tags/") {
-		return []string{"latest"}
+		return []string{"latest"}, nil
 	}
 	v := stripTagPrefix(ref)
 	version, err := semver.NewVersion(v)
 	if err != nil {
-		return []string{"latest"}
+		return []string{"latest"}, err
 	}
 	if version.PreRelease != "" || version.Metadata != "" {
 		return []string{
 			version.String(),
-		}
+		}, nil
 	}
 
 	v = stripTagPrefix(ref)
@@ -59,13 +62,13 @@ func DefaultTags(ref string) []string {
 		return []string{
 			fmt.Sprintf("%0*d.%0*d", len(dotParts[0]), version.Major, len(dotParts[1]), version.Minor),
 			fmt.Sprintf("%0*d.%0*d.%0*d", len(dotParts[0]), version.Major, len(dotParts[1]), version.Minor, len(dotParts[2]), version.Patch),
-		}
+		}, nil
 	}
 	return []string{
 		fmt.Sprintf("%0*d", len(dotParts[0]), version.Major),
 		fmt.Sprintf("%0*d.%0*d", len(dotParts[0]), version.Major, len(dotParts[1]), version.Minor),
 		fmt.Sprintf("%0*d.%0*d.%0*d", len(dotParts[0]), version.Major, len(dotParts[1]), version.Minor, len(dotParts[2]), version.Patch),
-	}
+	}, nil
 }
 
 // UseDefaultTag for keep only default branch for latest tag

tags_test.go

@@ -34,20 +34,35 @@ func TestDefaultTags(t *testing.T) {
 		{"refs/tags/1.0.0", []string{"1", "1.0", "1.0.0"}},
 		{"refs/tags/v1.0.0", []string{"1", "1.0", "1.0.0"}},
 		{"refs/tags/v1.0.0-alpha.1", []string{"1.0.0-alpha.1"}},
-
-		// malformed or errors
-		{"refs/tags/x1.0.0", []string{"latest"}},
-		{"v1.0.0", []string{"latest"}},
 	}
 
 	for _, test := range tests {
-		got, want := DefaultTags(test.Before), test.After
+		tags, err := DefaultTags(test.Before)
+		if err != nil {
+			t.Error(err)
+			continue
+		}
+		got, want := tags, test.After
 		if !reflect.DeepEqual(got, want) {
 			t.Errorf("Got tag %v, want %v", got, want)
 		}
 	}
 }
 
+func TestDefaultTagsError(t *testing.T) {
+	var tests = []string{
+		"refs/tags/x1.0.0",
+		"refs/tags/20190203",
+	}
+
+	for _, test := range tests {
+		_, err := DefaultTags(test)
+		if err == nil {
+			t.Errorf("Expect tag error for %s", test)
+		}
+	}
+}
+
 func TestDefaultTagSuffix(t *testing.T) {
 	var tests = []struct {
 		Before string
@@ -105,7 +120,12 @@ func TestDefaultTagSuffix(t *testing.T) {
 	}
 
 	for _, test := range tests {
-		got, want := DefaultTagSuffix(test.Before, test.Suffix), test.After
+		tag, err := DefaultTagSuffix(test.Before, test.Suffix)
+		if err != nil {
+			t.Error(err)
+			continue
+		}
+		got, want := tag, test.After
 		if !reflect.DeepEqual(got, want) {
 			t.Errorf("Got tag %v, want %v", got, want)
 		}