feat(storage): returned wrapped error for timeouts

storage/bucket.go

@@ -23,6 +23,7 @@ import (
 
 	"cloud.google.com/go/internal/optional"
 	"cloud.google.com/go/internal/trace"
+	"golang.org/x/xerrors"
 	"google.golang.org/api/googleapi"
 	"google.golang.org/api/iterator"
 	raw "google.golang.org/api/storage/v1"
@@ -166,7 +167,8 @@ func (b *BucketHandle) Attrs(ctx context.Context) (attrs *BucketAttrs, err error
 		resp, err = req.Context(ctx).Do()
 		return err
 	})
-	if e, ok := err.(*googleapi.Error); ok && e.Code == http.StatusNotFound {
+	var e *googleapi.Error
+	if ok := xerrors.As(err, &e); ok && e.Code == http.StatusNotFound {
 		return nil, ErrBucketNotExist
 	}
 	if err != nil {
@@ -1308,7 +1310,8 @@ func (it *ObjectIterator) fetch(pageSize int, pageToken string) (string, error)
 		return err
 	})
 	if err != nil {
-		if e, ok := err.(*googleapi.Error); ok && e.Code == http.StatusNotFound {
+		var e *googleapi.Error
+		if ok := xerrors.As(err, &e); ok && e.Code == http.StatusNotFound {
 			err = ErrBucketNotExist
 		}
 		return "", err

storage/doc.go

@@ -247,9 +247,10 @@ as the documentation of GenerateSignedPostPolicyV4.
 Errors
 
 Errors returned by this client are often of the type [`googleapi.Error`](https://godoc.org/google.golang.org/api/googleapi#Error).
-These errors can be introspected for more information by type asserting to the richer `googleapi.Error` type. For example:
+These errors can be introspected for more information by using `errors.As` with the richer `googleapi.Error` type. For example:
 
-	if e, ok := err.(*googleapi.Error); ok {
+	var e *googleapi.Error
+	if ok := errors.As(err, &e); ok {
 		  if e.Code == 409 { ... }
 	}
 */

storage/integration_test.go

@@ -1499,16 +1499,17 @@ func TestIntegration_Objects(t *testing.T) {
 	// Since a 429 or 5xx is hard to cause, we trigger a 416.
 	realLen := len(contents[objName])
 	_, err := bkt.Object(objName).NewRangeReader(ctx, int64(realLen*2), 10)
-	if err, ok := err.(*googleapi.Error); !ok {
+	var e *googleapi.Error
+	if ok := xerrors.As(err, &e); !ok {
 		t.Error("NewRangeReader did not return a googleapi.Error")
 	} else {
-		if err.Code != 416 {
-			t.Errorf("Code = %d; want %d", err.Code, 416)
+		if e.Code != 416 {
+			t.Errorf("Code = %d; want %d", e.Code, 416)
 		}
-		if len(err.Header) == 0 {
+		if len(e.Header) == 0 {
 			t.Error("Missing googleapi.Error.Header")
 		}
-		if len(err.Body) == 0 {
+		if len(e.Body) == 0 {
 			t.Error("Missing googleapi.Error.Body")
 		}
 	}
@@ -2773,8 +2774,9 @@ func TestIntegration_RequesterPays(t *testing.T) {
 		if err == nil {
 			return 0
 		}
-		if err, ok := err.(*googleapi.Error); ok {
-			return err.Code
+		var e *googleapi.Error
+		if ok := xerrors.As(err, &e); ok {
+			return e.Code
 		}
 		return -1
 	}
@@ -3023,7 +3025,8 @@ func TestIntegration_PublicBucket(t *testing.T) {
 	}
 
 	errCode := func(err error) int {
-		err2, ok := err.(*googleapi.Error)
+		var err2 *googleapi.Error
+		ok := xerrors.As(err, &err2)
 		if !ok {
 			return -1
 		}
@@ -3206,14 +3209,12 @@ func TestIntegration_CancelWrite(t *testing.T) {
 	cancel()
 	// The next Write should return context.Canceled.
 	_, err = w.Write(buf)
-	// TODO: Once we drop support for Go versions < 1.13, use errors.Is() to
-	// check for context cancellation instead.
-	if err != context.Canceled && !strings.Contains(err.Error(), "context canceled") {
+	if !xerrors.Is(err, context.Canceled) {
 		t.Fatalf("got %v, wanted context.Canceled", err)
 	}
 	// The Close should too.
 	err = w.Close()
-	if err != context.Canceled && !strings.Contains(err.Error(), "context canceled") {
+	if !xerrors.Is(err, context.Canceled) {
 		t.Fatalf("got %v, wanted context.Canceled", err)
 	}
 }
@@ -3865,7 +3866,7 @@ func TestIntegration_ReaderCancel(t *testing.T) {
 		buf := make([]byte, 1000)
 		_, readErr = r.Read(buf)
 		if readErr != nil {
-			if readErr == context.Canceled {
+			if xerrors.Is(readErr, context.Canceled) {
 				return
 			}
 			break

storage/invoke.go

@@ -36,7 +36,7 @@ func runWithRetry(ctx context.Context, call func() error) error {
 			return true, nil
 		}
 		if shouldRetry(err) {
-			return false, nil
+			return false, err
 		}
 		return true, err
 	})

storage/retry_test.go

@@ -25,6 +25,7 @@ import (
 	"time"
 
 	"golang.org/x/oauth2"
+	"golang.org/x/xerrors"
 
 	"cloud.google.com/go/storage"
 	"google.golang.org/api/googleapi"
@@ -160,7 +161,8 @@ func TestIndefiniteRetries(t *testing.T) {
 	case <-time.After(maxWait):
 		t.Fatalf("Test took longer than %s to return", maxWait)
 	case err := <-closeDone:
-		ge, ok := err.(*googleapi.Error)
+		var ge *googleapi.Error
+		ok := xerrors.As(err, &ge)
 		if !ok {
 			t.Fatalf("Got error (%v) of type %T, expected *googleapi.Error", err, err)
 		}

storage/storage.go

@@ -41,6 +41,7 @@ import (
 	"cloud.google.com/go/internal/trace"
 	"cloud.google.com/go/internal/version"
 	gapic "cloud.google.com/go/storage/internal/apiv2"
+	"golang.org/x/xerrors"
 	"google.golang.org/api/googleapi"
 	"google.golang.org/api/option"
 	"google.golang.org/api/option/internaloption"
@@ -867,7 +868,8 @@ func (o *ObjectHandle) Attrs(ctx context.Context) (attrs *ObjectAttrs, err error
 	var obj *raw.Object
 	setClientHeader(call.Header())
 	err = runWithRetry(ctx, func() error { obj, err = call.Do(); return err })
-	if e, ok := err.(*googleapi.Error); ok && e.Code == http.StatusNotFound {
+	var e *googleapi.Error
+	if ok := xerrors.As(err, &e); ok && e.Code == http.StatusNotFound {
 		return nil, ErrObjectNotExist
 	}
 	if err != nil {
@@ -967,7 +969,8 @@ func (o *ObjectHandle) Update(ctx context.Context, uattrs ObjectAttrsToUpdate) (
 	var obj *raw.Object
 	setClientHeader(call.Header())
 	err = runWithRetry(ctx, func() error { obj, err = call.Do(); return err })
-	if e, ok := err.(*googleapi.Error); ok && e.Code == http.StatusNotFound {
+	var e *googleapi.Error
+	if ok := xerrors.As(err, &e); ok && e.Code == http.StatusNotFound {
 		return nil, ErrObjectNotExist
 	}
 	if err != nil {
@@ -1030,13 +1033,9 @@ func (o *ObjectHandle) Delete(ctx context.Context) error {
 	// Encryption doesn't apply to Delete.
 	setClientHeader(call.Header())
 	err := runWithRetry(ctx, func() error { return call.Do() })
-	switch e := err.(type) {
-	case nil:
-		return nil
-	case *googleapi.Error:
-		if e.Code == http.StatusNotFound {
-			return ErrObjectNotExist
-		}
+	var e *googleapi.Error
+	if ok := xerrors.As(err, &e); ok && e.Code == http.StatusNotFound {
+		return ErrObjectNotExist
 	}
 	return err
 }

storage/writer.go

@@ -24,6 +24,7 @@ import (
 	"unicode/utf8"
 
 	"github.com/golang/protobuf/proto"
+	"golang.org/x/xerrors"
 	"google.golang.org/api/googleapi"
 	raw "google.golang.org/api/storage/v1"
 	storagepb "google.golang.org/genproto/googleapis/storage/v2"
@@ -217,7 +218,7 @@ func (w *Writer) Write(p []byte) (n int, err error) {
 		// Preserve existing functionality that when context is canceled, Write will return
 		// context.Canceled instead of "io: read/write on closed pipe". This hides the
 		// pipe implementation detail from users and makes Write seem as though it's an RPC.
-		if werr == context.Canceled || werr == context.DeadlineExceeded {
+		if xerrors.Is(werr, context.Canceled) || xerrors.Is(werr, context.DeadlineExceeded) {
 			return n, werr
 		}
 	}