Merge pull request #36 from celestiaorg/mojtaba/sdk-error-enhancement

feat: add a more precise error handling to the SDK

.gitignore

@@ -20,6 +20,5 @@
 # Go workspace file
 go.work
 bin/
-*.o
 run.sh
 .vscode/

api/v1/api.go

@@ -14,10 +14,10 @@ import (
 	"go.uber.org/zap"
 )
 
-const baseUrl = "/api/v1"
+const EndpointPrefix = "/api/v1"
 
 func path(endpoint string) string {
-	return baseUrl + endpoint
+	return EndpointPrefix + endpoint
 }
 
 func NewRESTApiV1(productionMode bool, logger *zap.Logger) *RESTApiV1 {

api/v1/net_services_utils.go

@@ -7,13 +7,7 @@ import (
 )
 
 func netServiceStart(resp http.ResponseWriter, ns *netRestrictService, ifaceName string) error {
-	if ns == nil || ns.service == nil {
-		sendJSONError(resp, MetaMessage{
-			Type:    APIMetaMessageTypeError,
-			Slug:    SlugServiceNotInitialized,
-			Title:   "Service not initiated",
-			Message: "To get the status of the service, it must be started first.",
-		}, http.StatusOK)
+	if !ensureServiceInitialized(resp, ns) {
 		return ErrServiceNotInitialized
 	}
 
@@ -43,13 +37,7 @@ func netServiceStart(resp http.ResponseWriter, ns *netRestrictService, ifaceName
 }
 
 func netServiceStop(resp http.ResponseWriter, ns *netRestrictService) error {
-	if ns == nil || ns.service == nil {
-		sendJSONError(resp, MetaMessage{
-			Type:    APIMetaMessageTypeError,
-			Slug:    SlugServiceNotInitialized,
-			Title:   "Service not initiated",
-			Message: "To get the status of the service, it must be started first.",
-		}, http.StatusOK)
+	if !ensureServiceInitialized(resp, ns) {
 		return ErrServiceNotInitialized
 	}
 
@@ -104,7 +92,7 @@ func netServiceStatus(resp http.ResponseWriter, ns *netRestrictService) error {
 			Slug:    SlugServiceNotInitialized,
 			Title:   "Service not initiated",
 			Message: "To get the status of the service, it must be started first.",
-		}, http.StatusOK)
+		}, http.StatusInternalServerError)
 		return ErrServiceNotInitialized
 	}
 
@@ -125,7 +113,7 @@ func netServiceStatus(resp http.ResponseWriter, ns *netRestrictService) error {
 }
 
 func ensureServiceInitialized(resp http.ResponseWriter, ns *netRestrictService) bool {
-	if ns != nil {
+	if ns != nil && ns.service != nil {
 		return true
 	}
 	sendJSONError(resp,

sdk/apis.go

@@ -6,60 +6,59 @@ import (
 	"github.com/celestiaorg/bittwister/api/v1"
 )
 
+const endpointPrefix = api.EndpointPrefix
+
 type PacketLossStartRequest = api.PacketLossStartRequest
 type BandwidthStartRequest = api.BandwidthStartRequest
 type LatencyStartRequest = api.LatencyStartRequest
 type ServiceStatus = api.ServiceStatus
 type MetaMessage = api.MetaMessage
 
 func (c *Client) PacketlossStart(req PacketLossStartRequest) error {
-	_, err := c.postResource("/packetloss/start", req)
-	return err
+	return c.postServiceAction(endpointPrefix+"/packetloss/start", req)
 }
 
 func (c *Client) PacketlossStop() error {
-	_, err := c.postResource("/packetloss/stop", nil)
-	return err
+	return c.postServiceAction(endpointPrefix+"/packetloss/stop", nil)
 }
 
 func (c *Client) PacketlossStatus() (*MetaMessage, error) {
-	return c.getServiceStatus("/packetloss/status")
+	return c.getServiceStatus(endpointPrefix + "/packetloss/status")
 }
 
 func (c *Client) BandwidthStart(req BandwidthStartRequest) error {
-	_, err := c.postResource("/bandwidth/start", req)
-	return err
+	return c.postServiceAction(endpointPrefix+"/bandwidth/start", req)
 }
 
 func (c *Client) BandwidthStop() error {
-	_, err := c.postResource("/bandwidth/stop", nil)
-	return err
+	return c.postServiceAction(endpointPrefix+"/bandwidth/stop", nil)
 }
 
 func (c *Client) BandwidthStatus() (*MetaMessage, error) {
-	return c.getServiceStatus("/bandwidth/status")
+	return c.getServiceStatus(endpointPrefix + "/bandwidth/status")
 }
 
 func (c *Client) LatencyStart(req LatencyStartRequest) error {
-	_, err := c.postResource("/latency/start", req)
-	return err
+	return c.postServiceAction(endpointPrefix+"/latency/start", req)
 }
 
 func (c *Client) LatencyStop() error {
-	_, err := c.postResource("/latency/stop", nil)
-	return err
+	return c.postServiceAction(endpointPrefix+"/latency/stop", nil)
 }
 
 func (c *Client) LatencyStatus() (*MetaMessage, error) {
-	return c.getServiceStatus("/latency/status")
+	return c.getServiceStatus(endpointPrefix + "/latency/status")
 }
 
 func (c *Client) AllServicesStatus() ([]ServiceStatus, error) {
-	resp, err := c.getResource("/services/status")
-	msgs := []api.ServiceStatus{}
+	resp, err := c.getResource(endpointPrefix + "/services/status")
+	if err != nil {
+		return nil, err
+	}
 
+	msgs := []api.ServiceStatus{}
 	if err := json.Unmarshal(resp, &msgs); err != nil {
 		return nil, err
 	}
-	return msgs, err
+	return msgs, nil
 }

sdk/client.go

@@ -29,16 +29,17 @@ func (c *Client) getResource(resPath string) ([]byte, error) {
 	}
 	defer resp.Body.Close()
 
-	if resp.StatusCode != http.StatusOK {
-		return nil, fmt.Errorf("unexpected status: %d", resp.StatusCode)
-	}
-
 	body, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return nil, err
 	}
 
-	return body, nil
+	var statusErr error
+	if resp.StatusCode != http.StatusOK {
+		statusErr = fmt.Errorf("unexpected status: %d", resp.StatusCode)
+	}
+
+	return body, statusErr
 }
 
 func (c *Client) postResource(resPath string, requestBody interface{}) ([]byte, error) {
@@ -59,27 +60,45 @@ func (c *Client) postResource(resPath string, requestBody interface{}) ([]byte,
 	}
 	defer resp.Body.Close()
 
-	if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusCreated {
-		return nil, fmt.Errorf("unexpected status: %d", resp.StatusCode)
-	}
-
 	body, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return nil, err
 	}
 
-	return body, nil
+	var statusErr error
+	if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusCreated {
+		statusErr = fmt.Errorf("unexpected status: %d", resp.StatusCode)
+	}
+
+	return body, statusErr
 }
 
 func (c *Client) getServiceStatus(resPath string) (*api.MetaMessage, error) {
 	resp, err := c.getResource(resPath)
 	if err != nil {
 		return nil, err
 	}
-	msg := &api.MetaMessage{}
 
+	msg := &api.MetaMessage{}
 	if err := json.Unmarshal(resp, msg); err != nil {
 		return nil, err
 	}
 	return msg, nil
 }
+
+func (c *Client) postServiceAction(resPath string, req interface{}) error {
+	resp, err := c.postResource(resPath, req)
+	if err == nil {
+		return nil
+	}
+
+	if len(resp) == 0 {
+		return fmt.Errorf("postResource: %w", err)
+	}
+
+	msg := api.MetaMessage{}
+	if err := json.Unmarshal(resp, &msg); err != nil {
+		return fmt.Errorf("raw output: %s", string(resp))
+	}
+	return Error{Message: msg}
+}

sdk/errors.go

@@ -0,0 +1,65 @@
+package sdk
+
+import (
+	"encoding/json"
+
+	"github.com/celestiaorg/bittwister/api/v1"
+)
+
+type Error struct {
+	Message MetaMessage
+}
+
+// Error returns the error message as a string
+func (e Error) Error() string {
+	errJSON, _ := json.MarshalIndent(e.Message, "", "  ")
+	return string(errJSON)
+}
+
+func IsErrorServiceNotInitialized(err error) bool {
+	e, ok := err.(Error)
+	if !ok {
+		return false
+	}
+	return e.Message.Slug == api.SlugServiceNotInitialized
+}
+
+func IsErrorServiceAlreadyStarted(err error) bool {
+	e, ok := err.(Error)
+	if !ok {
+		return false
+	}
+	return e.Message.Slug == api.SlugServiceAlreadyStarted
+}
+
+func IsErrorServiceNotStarted(err error) bool {
+	e, ok := err.(Error)
+	if !ok {
+		return false
+	}
+	return e.Message.Slug == api.SlugServiceNotStarted
+}
+
+func IsErrorServiceStopFailed(err error) bool {
+	e, ok := err.(Error)
+	if !ok {
+		return false
+	}
+	return e.Message.Slug == api.SlugServiceStopFailed
+}
+
+func IsErrorServiceStartFailed(err error) bool {
+	e, ok := err.(Error)
+	if !ok {
+		return false
+	}
+	return e.Message.Slug == api.SlugServiceStartFailed
+}
+
+func IsErrorServiceNotReady(err error) bool {
+	e, ok := err.(Error)
+	if !ok {
+		return false
+	}
+	return e.Message.Slug == api.SlugServiceNotReady
+}

sdk/sdk_test.go

@@ -42,7 +42,7 @@ func Test_SDK_Client_GetResource_HTTPError(t *testing.T) {
 
 	client := NewClient(mockServer.URL)
 	res, err := client.getResource("/error")
-	assert.Nil(t, res)
+	assert.Empty(t, res)
 	assert.Error(t, err)
 }
 
@@ -113,7 +113,7 @@ func Test_SDK_Client_PostResource_HTTPError(t *testing.T) {
 		client := NewClient(mockServer.URL)
 		res, err := client.postResource("/error", nil)
 
-		assert.Nil(t, res)
+		assert.Empty(t, res)
 		assert.Error(t, err)
 	}
 }