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js: smaller JetStreamError interface, make JetStreamAPIError concrete…
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… type

Signed-off-by: Waldemar Quevedo <wally@nats.io>
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@wallyqs
wallyqs committed Aug 22, 2022
1 parent a89ee00 commit 21ea50a
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Showing 3 changed files with 65 additions and 75 deletions.
86 changes: 30 additions & 56 deletions jsm.go
View file
Expand Up @@ -154,76 +154,60 @@ type ExternalStream struct {
DeliverPrefix string `json:"deliver"`
}

// APIError is included in all API responses if there was an error.
type APIError struct {
// JetStreamAPIError is included in all API responses if there was an error.
type JetStreamAPIError struct {
Code int `json:"code"`
ErrorCode ErrorCode `json:"err_code"`
Description string `json:"description,omitempty"`
}

// Error prints the JetStream API error code and description
func (e *APIError) Error() string {
func (e *JetStreamAPIError) Error() string {
return fmt.Sprintf("nats: API error %d: %s", e.ErrorCode, e.Description)
}

// Is matches against an APIError.
func (e *APIError) Is(err error) bool {
// Is matches against an JetStreamAPIError.
func (e *JetStreamAPIError) Is(err error) bool {
// Extract internal APIError to match against.
var aerr *APIError
var aerr *JetStreamAPIError
ok := errors.As(err, &aerr)
if !ok {
return ok
}
return e.ErrorCode == aerr.ErrorCode
}

// JetStreamAPIError is an error result from making a request to the
// JetStream API.
type JetStreamAPIError interface {
Code() int
ErrorCode() ErrorCode
Description() string
// JetStreamError is an error result that happens when using JetStream.
type JetStreamError interface {
APIError() *JetStreamAPIError
error
}

type jsAPIError struct {
code int
errorCode ErrorCode
description string
message string
type jsError struct {
apiErr *JetStreamAPIError
message string
}

func (err *jsAPIError) Code() int {
return err.code
func (err *jsError) APIError() *JetStreamAPIError {
return err.apiErr
}

func (err *jsAPIError) ErrorCode() ErrorCode {
return err.errorCode
}

func (err *jsAPIError) Description() string {
if err.description == "" {
return err.message
func (err *jsError) Error() string {
if err.apiErr != nil && err.apiErr.Description != "" {
return fmt.Sprintf("nats: %v", err.apiErr.Description)
}
return err.description
}

func (err *jsAPIError) Error() string {
return fmt.Sprintf("nats: %v", err.message)
}

func (err *jsAPIError) Unwrap() error {
return &APIError{
Code: err.Code(),
ErrorCode: err.ErrorCode(),
Description: err.Description(),
}
func (err *jsError) Unwrap() error {
// Allow matching to embedded APIError in case there is one.
return err.apiErr
}

// apiResponse is a standard response from the JetStream JSON API
type apiResponse struct {
Type string `json:"type"`
Error *APIError `json:"error,omitempty"`
Type string `json:"type"`
Error *JetStreamAPIError `json:"error,omitempty"`
}

// apiPaged includes variables used to create paged responses from the JSON API
Expand Down Expand Up @@ -294,14 +278,6 @@ const (
JSErrCodeMessageNotFound ErrorCode = 10037
)

var (
// ErrJetStreamNotEnabled is an error returned when JetStream is not enabled.
ErrJetStreamNotEnabledForAccount JetStreamAPIError = &jsAPIError{errorCode: JSErrCodeJetStreamNotEnabledForAccount, description: "nats: jetstream not enabled for account"}

// ErrJetStreamNotEnabledForAccount is an error returned when JetStream is not enabled for an account.
ErrJetStreamNotEnabled JetStreamAPIError = &jsAPIError{errorCode: JSErrCodeJetStreamNotEnabled, description: "nats: jetstream not enabled"}
)

// AccountInfo retrieves info about the JetStream usage from the current account.
// If JetStream is not enabled, this will return ErrJetStreamNotEnabled
// Other errors can happen but are generally considered retryable
Expand Down Expand Up @@ -330,12 +306,10 @@ func (js *js) AccountInfo(opts ...JSOpt) (*AccountInfo, error) {
var err error
// Internally checks based on error code instead of description match.
if errors.Is(info.Error, ErrJetStreamNotEnabledForAccount) {
err = ErrJetStreamNotEnabled
err = ErrJetStreamNotEnabledForAccount
} else {
err = &jsAPIError{
code: info.Error.Code,
errorCode: info.Error.ErrorCode,
description: info.Error.Description,
err = &jsError{
apiErr: info.Error,
}
}
return nil, err
Expand Down Expand Up @@ -829,11 +803,11 @@ type StreamInfo struct {

// StreamSourceInfo shows information about an upstream stream source.
type StreamSourceInfo struct {
Name string `json:"name"`
Lag uint64 `json:"lag"`
Active time.Duration `json:"active"`
External *ExternalStream `json:"external"`
Error *APIError `json:"error"`
Name string `json:"name"`
Lag uint64 `json:"lag"`
Active time.Duration `json:"active"`
External *ExternalStream `json:"external"`
Error *JetStreamAPIError `json:"error"`
}

// StreamState is information about the given stream.
Expand Down
14 changes: 12 additions & 2 deletions nats.go
View file
Expand Up @@ -153,14 +153,13 @@ var (
ErrStreamNameRequired = errors.New("nats: stream name is required")
ErrStreamNotFound = errors.New("nats: stream not found")
ErrConsumerNotFound = errors.New("nats: consumer not found")
ErrConsumerNameAlreadyInUse = errors.New("nats: consumer name already in use")
ErrConsumerNameRequired = errors.New("nats: consumer name is required")
ErrConsumerConfigRequired = errors.New("nats: consumer configuration is required")
ErrStreamSnapshotConfigRequired = errors.New("nats: stream snapshot configuration is required")
ErrDeliverSubjectRequired = errors.New("nats: deliver subject is required")
ErrPullSubscribeToPushConsumer = errors.New("nats: cannot pull subscribe to push based consumer")
ErrPullSubscribeRequired = errors.New("nats: must use pull subscribe to bind to pull based consumer")
ErrConsumerNameAlreadyInUse = errors.New("nats: consumer name already in use")
ErrConsumerNotActive = errors.New("nats: consumer not active")
ErrMsgNotFound = errors.New("nats: message not found")
ErrMsgAlreadyAckd = errors.New("nats: message was already acknowledged")
ErrCantAckIfConsumerAckNone = errors.New("nats: cannot acknowledge a message for a consumer with AckNone policy")
Expand All @@ -171,6 +170,17 @@ var (
ErrConnectionNotTLS = errors.New("nats: connection is not tls")
)

var (
// ErrJetStreamNotEnabled is an error returned when JetStream is not enabled for an account.
ErrJetStreamNotEnabled JetStreamError = &jsError{apiErr: &JetStreamAPIError{ErrorCode: JSErrCodeJetStreamNotEnabled, Description: "jetstream not enabled"}}

// ErrJetStreamNotEnabledForAccount is an error returned when JetStream is not enabled for an account.
ErrJetStreamNotEnabledForAccount JetStreamError = &jsError{apiErr: &JetStreamAPIError{ErrorCode: JSErrCodeJetStreamNotEnabledForAccount, Description: "jetstream not enabled"}}

// ErrConsumerNotActive is an error returned when consumer is not active.
ErrConsumerNotActive JetStreamError = &jsError{message: "consumer not active"}
)

func init() {
rand.Seed(time.Now().UnixNano())
}
Expand Down
40 changes: 23 additions & 17 deletions test/js_test.go
View file
Expand Up @@ -94,8 +94,8 @@ func TestJetStreamNotAccountEnabled(t *testing.T) {
}

// matching via errors.Is
if ok := errors.Is(err, nats.ErrJetStreamNotEnabled); !ok {
t.Fatal("Expected ErrJetStreamNotEnabled")
if ok := errors.Is(err, nats.ErrJetStreamNotEnabledForAccount); !ok {
t.Fatal("Expected ErrJetStreamNotEnabledForAccount")
}

// matching wrapped via error.Is
Expand All @@ -105,41 +105,47 @@ func TestJetStreamNotAccountEnabled(t *testing.T) {
}

// via classic type assertion.
jserr, ok := err.(nats.JetStreamAPIError)
jserr, ok := err.(nats.JetStreamError)
if !ok {
t.Fatal("Expected a JetStreamAPIError")
t.Fatal("Expected a JetStreamError")
}
expected := nats.JSErrCodeJetStreamNotEnabledForAccount
if jserr.ErrorCode() != nats.ErrorCode(expected) {
t.Fatalf("Expected: %v, got: %v", expected, jserr.ErrorCode())
if jserr.APIError().ErrorCode != expected {
t.Fatalf("Expected: %v, got: %v", expected, jserr.APIError().ErrorCode)
}
if jserr.APIError() == nil {
t.Fatal("Expected APIError")
}

// matching to interface via errors.As(...)
var apierr nats.JetStreamAPIError
var apierr nats.JetStreamError
ok = errors.As(err, &apierr)
if !ok {
t.Fatal("Expected a JetStreamAPIError")
t.Fatal("Expected a JetStreamError")
}
if apierr.APIError() == nil {
t.Fatal("Expected APIError")
}
if apierr.ErrorCode() != expected {
t.Fatalf("Expected: %v, got: %v", expected, apierr.ErrorCode())
if apierr.APIError().ErrorCode != expected {
t.Fatalf("Expected: %v, got: %v", expected, apierr.APIError().ErrorCode)
}
expectedMessage := "nats: jetstream not enabled"
if apierr.Error() != expectedMessage {
t.Fatalf("Expected: %v, got: %v", expectedMessage, apierr.Error())
}

// matching arbitrary custom error via errors.Is(...)
customErr := &nats.APIError{ErrorCode: expected}
if ok := errors.Is(customErr, nats.ErrJetStreamNotEnabled); !ok {
t.Fatal("Expected wrapped ErrJetStreamNotEnabled")
customErr := &nats.JetStreamAPIError{ErrorCode: expected}
if ok := errors.Is(customErr, nats.ErrJetStreamNotEnabledForAccount); !ok {
t.Fatal("Expected wrapped ErrJetStreamNotEnabledForAccount")
}
customErr = &nats.APIError{ErrorCode: 1}
if ok := errors.Is(customErr, nats.ErrJetStreamNotEnabled); ok {
customErr = &nats.JetStreamAPIError{ErrorCode: 1}
if ok := errors.Is(customErr, nats.ErrJetStreamNotEnabledForAccount); ok {
t.Fatal("Expected to not match ErrJetStreamNotEnabled")
}

// matching to concrete type via errors.As(...)
var aerr *nats.APIError
var aerr *nats.JetStreamAPIError
ok = errors.As(err, &aerr)
if !ok {
t.Fatal("Expected an APIError")
Expand Down Expand Up @@ -4894,7 +4900,7 @@ func testJetStreamMirror_Source(t *testing.T, nodes ...*jsServer) {
if err == nil {
t.Fatal("Unexpected success")
}
apiErr := &nats.APIError{}
apiErr := &nats.JetStreamAPIError{}
if !errors.As(err, &apiErr) || apiErr.ErrorCode != 10093 {
t.Fatalf("Expected API error 10093; got: %v", err)
}
Expand Down

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