Improve errors

neo4j/config_resolver.go

@@ -38,7 +38,7 @@ type ServerAddress interface {
 // resolve the initial address used to create the driver.
 type ServerAddressResolver func(address ServerAddress) []ServerAddress
 
-func newServerAddressUrl(hostname string, port string) *url.URL {
+func newServerAddressURL(hostname string, port string) *url.URL {
 	if hostname == "" {
 		return nil
 	}
@@ -51,12 +51,12 @@ func newServerAddressUrl(hostname string, port string) *url.URL {
 	return &url.URL{Host: hostAndPort}
 }
 
-// A helper function that generates a ServerAddress with provided hostname and port information.
+// NewServerAddress generates a ServerAddress with provided hostname and port information.
 func NewServerAddress(hostname string, port string) ServerAddress {
-	return newServerAddressUrl(hostname, port)
+	return newServerAddressURL(hostname, port)
 }
 
-func wrapAddressResolverOrNil(addressResolver ServerAddressResolver) gobolt.UrlAddressResolver {
+func wrapAddressResolverOrNil(addressResolver ServerAddressResolver) gobolt.URLAddressResolver {
 	if addressResolver == nil {
 		return nil
 	}
@@ -65,7 +65,7 @@ func wrapAddressResolverOrNil(addressResolver ServerAddressResolver) gobolt.UrlA
 		var result []*url.URL
 
 		for _, address := range addressResolver(address) {
-			result = append(result, newServerAddressUrl(address.Hostname(), address.Port()))
+			result = append(result, newServerAddressURL(address.Hostname(), address.Port()))
 		}
 
 		return result

neo4j/error.go

@@ -24,31 +24,142 @@ import (
 	"github.com/neo4j-drivers/gobolt"
 )
 
+type databaseError struct {
+	classification string
+	code           string
+	message        string
+}
+
+type connectorError struct {
+	state       int
+	code        int
+	description string
+}
+
 type driverError struct {
 	message string
 }
 
-func newDriverError(format string, args ...interface{}) error {
+type sessionExpiredError struct {
+	message string
+}
+
+func (failure *databaseError) BoltError() bool {
+	return true
+}
+
+func (failure *databaseError) Classification() string {
+	return failure.classification
+}
+
+func (failure *databaseError) Code() string {
+	return failure.code
+}
+
+func (failure *databaseError) Message() string {
+	return failure.message
+}
+
+func (failure *databaseError) Error() string {
+	return fmt.Sprintf("database returned error [%s]: %s", failure.code, failure.message)
+}
+
+func (failure *connectorError) BoltError() bool {
+	return true
+}
+
+func (failure *connectorError) State() int {
+	return failure.state
+}
+
+func (failure *connectorError) Code() int {
+	return failure.code
+}
+
+func (failure *connectorError) Description() string {
+	return failure.description
+}
+
+func (failure *connectorError) Error() string {
+	return fmt.Sprintf("expected connection to be in READY state, where it is %d [error is %d]", failure.state, failure.code)
+}
+
+func (failure *driverError) BoltError() bool {
+	return true
+}
+
+func (failure *driverError) Message() string {
+	return failure.message
+}
+
+func (failure *driverError) Error() string {
+	return failure.message
+}
+
+func (failure *sessionExpiredError) BoltError() bool {
+	return true
+}
+
+func (failure *sessionExpiredError) Error() string {
+	return failure.message
+}
+
+func newDriverError(format string, args ...interface{}) gobolt.GenericError {
 	return &driverError{message: fmt.Sprintf(format, args...)}
 }
 
+func newSessionExpiredError(format string, args ...interface{}) error {
+	return &sessionExpiredError{message: fmt.Sprintf(format, args...)}
+}
+
+func newDatabaseError(classification, code, message string) gobolt.DatabaseError {
+	return &databaseError{code: code, message: message, classification: classification}
+}
+
+func newConnectorError(state int, code int, description string) gobolt.ConnectorError {
+	return &connectorError{state: state, code: code, description: description}
+}
+
 func isRetriableError(err error) bool {
 	return gobolt.IsServiceUnavailable(err) || gobolt.IsTransientError(err) || gobolt.IsWriteError(err)
 }
 
-func (err *driverError) Error() string {
-	return err.message
+// IsSecurityError is a utility method to check if the provided error is related with any
+// TLS failure or authentication issues.
+func IsSecurityError(err error) bool {
+	return gobolt.IsSecurityError(err)
 }
 
-func IsServiceUnavailable(err error) bool {
-	return gobolt.IsServiceUnavailable(err)
+// IsAuthenticationError is a utility method to check if the provided error is related with any
+// authentication issues.
+func IsAuthenticationError(err error) bool {
+	return gobolt.IsAuthenticationError(err)
 }
 
-func IsDriverError(err error) bool {
-	_, ok := err.(*driverError)
-	return ok
+// IsClientError is a utility method to check if the provided error is related with the client
+// carrying out an invalid operation.
+func IsClientError(err error) bool {
+	return gobolt.IsClientError(err)
 }
 
+// IsTransientError is a utility method to check if the provided error is related with a temporary
+// failure that may be worked around by retrying.
 func IsTransientError(err error) bool {
 	return gobolt.IsTransientError(err)
 }
+
+// IsSessionExpired is a utility method to check if the session no longer satisfy the criteria
+// under which it was acquired, e.g. a server no longer accepts write requests.
+func IsSessionExpired(err error) bool {
+	if _, ok := err.(*sessionExpiredError); ok {
+		return true
+	}
+
+	return gobolt.IsSessionExpired(err)
+}
+
+// IsServiceUnavailable is a utility method to check if the provided error can be classified
+// to be in service unavailable category.
+func IsServiceUnavailable(err error) bool {
+	return gobolt.IsServiceUnavailable(err)
+}