fix: s3: honor skip upload (#738)

refs https://github.com/goreleaser/goreleaser/issues/737

pipeline/s3/s3.go

@@ -15,6 +15,7 @@ import (
 	"github.com/goreleaser/goreleaser/internal/artifact"
 	"github.com/goreleaser/goreleaser/internal/semerrgroup"
 	"github.com/goreleaser/goreleaser/internal/tmpl"
+	"github.com/goreleaser/goreleaser/pipeline"
 )
 
 // Pipe for Artifactory
@@ -47,6 +48,9 @@ func (Pipe) Default(ctx *context.Context) error {
 
 // Run the pipe
 func (Pipe) Run(ctx *context.Context) error {
+	if ctx.SkipPublish {
+		return pipeline.ErrSkipPublishEnabled
+	}
 	var g = semerrgroup.New(ctx.Parallelism)
 	for _, conf := range ctx.Config.S3 {
 		conf := conf

pipeline/s3/s3_test.go

@@ -13,7 +13,9 @@ import (
 	"github.com/goreleaser/goreleaser/config"
 	"github.com/goreleaser/goreleaser/context"
 	"github.com/goreleaser/goreleaser/internal/artifact"
+	"github.com/goreleaser/goreleaser/pipeline"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func TestDescription(t *testing.T) {
@@ -53,6 +55,34 @@ func TestDefaults(t *testing.T) {
 	}}, ctx.Config.S3)
 }
 
+func TestSkipPublish(t *testing.T) {
+	folder, err := ioutil.TempDir("", "goreleasertest")
+	require.NoError(t, err)
+	artifactPath := filepath.Join(folder, "foo.tar.gz")
+	require.NoError(t, ioutil.WriteFile(artifactPath, []byte("fake\ntargz"), 0744))
+	var ctx = context.New(config.Project{
+		Dist:        folder,
+		ProjectName: "testupload",
+		S3: []config.S3{
+			{
+				Bucket:   "test",
+				Endpoint: "http://fake.s3.example",
+			},
+		},
+	})
+	ctx.Git = context.GitInfo{CurrentTag: "v1.0.0"}
+	ctx.Artifacts.Add(artifact.Artifact{
+		Type: artifact.UploadableArchive,
+		Name: "foo.tar.gz",
+		Path: artifactPath,
+	})
+	ctx.SkipPublish = true
+	require.NoError(t, Pipe{}.Default(ctx))
+	err = Pipe{}.Run(ctx)
+	assert.True(t, pipeline.IsSkip(err))
+	assert.EqualError(t, err, pipeline.ErrSkipPublishEnabled.Error())
+}
+
 func TestUpload(t *testing.T) {
 	folder, err := ioutil.TempDir("", "goreleasertest")
 	assert.NoError(t, err)