unify repetitive response handling code

api.go

@@ -15,26 +15,34 @@ type APIResponse struct {
 	Message string  `json:"message,omitempty"`
 }
 
-func handleAPIResponse(bts []byte) (*APIResponse, error) {
-	var response *APIResponse
-	if err := json.Unmarshal(bts, &response); err != nil {
-		return nil, err
+type Response interface {
+	GetError() error
+}
+
+func (r APIResponse) GetError() error {
+	if len(r.Errors) != 0 {
+		for _, err := range r.Errors {
+			return err
+		}
 	}
 
-	return response, nil
+	return nil
 }
 
-func handleDeleteResponse(bts []byte) error {
-	rsp, err := handleAPIResponse(bts)
-	if err != nil {
+func checkAPIResponse(bts []byte, r Response) error {
+	if r == nil {
+		r = new(APIResponse)
+	}
+
+	if err := json.Unmarshal(bts, &r); err != nil {
 		return err
 	}
 
-	if len(rsp.Errors) != 0 {
-		return rsp.Errors[0]
+	if r == nil {
+		return ErrNoResponseData
 	}
 
-	return nil
+	return r.GetError()
 }
 
 func buildPath(parts ...string) string {

api_test.go

@@ -0,0 +1,105 @@
+package aiven
+
+import "testing"
+
+func Test_checkAPIResponse(t *testing.T) {
+	type args struct {
+		bts []byte
+		r   Response
+	}
+	tests := []struct {
+		name    string
+		args    args
+		wantErr bool
+	}{
+		{
+			"invalid-json",
+			args{
+				bts: []byte(`Invalid JSON`),
+				r:   nil,
+			},
+			true,
+		},
+		{
+			"error-response",
+			args{
+				bts: []byte(`{
+					"message": "Authentication failed",
+					"errors": [
+						{
+							"status": "403",
+							"message": "Authentication failed"
+						}
+					]
+				}`),
+				r: nil,
+			},
+			true,
+		},
+		{
+			"error-response",
+			args{
+				bts: []byte(`{
+					"message": "",
+					"errors": [
+					]
+				}`),
+				r: nil,
+			},
+			false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if err := checkAPIResponse(tt.args.bts, tt.args.r); (err != nil) != tt.wantErr {
+				t.Errorf("checkAPIResponse() error = %v, wantErr %v", err, tt.wantErr)
+			}
+		})
+	}
+}
+
+func TestAPIResponse_GetError(t *testing.T) {
+	type fields struct {
+		Errors  []Error
+		Message string
+	}
+	tests := []struct {
+		name    string
+		fields  fields
+		wantErr bool
+	}{
+		{
+			"empty",
+			fields{
+				Errors:  nil,
+				Message: "",
+			},
+			false,
+		},
+		{
+			"has-error",
+			fields{
+				Errors: []Error{
+					{
+						Message:  "error-message",
+						MoreInfo: "some-info",
+						Status:   500,
+					},
+				},
+				Message: "error-message",
+			},
+			true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			r := APIResponse{
+				Errors:  tt.fields.Errors,
+				Message: tt.fields.Message,
+			}
+			if err := r.GetError(); (err != nil) != tt.wantErr {
+				t.Errorf("GetError() error = %v, wantErr %v", err, tt.wantErr)
+			}
+		})
+	}
+}

ca.go

@@ -3,11 +3,6 @@
 
 package aiven
 
-import (
-	"encoding/json"
-	"errors"
-)
-
 type (
 	// CAHandler is the client which interacts with the Projects CA endpoint
 	// on Aiven.
@@ -29,21 +24,8 @@ func (h *CAHandler) Get(project string) (string, error) {
 		return "", err
 	}
 
-	if bts == nil {
-		return "", ErrNoResponseData
-	}
+	var r ProjectCAResponse
+	errR := checkAPIResponse(bts, &r)
 
-	var rsp *ProjectCAResponse
-	if err := json.Unmarshal(bts, &rsp); err != nil {
-		return "", err
-	}
-
-	if rsp == nil {
-		return "", ErrNoResponseData
-	}
-
-	if rsp.Errors != nil && len(rsp.Errors) != 0 {
-		return "", errors.New(rsp.Message)
-	}
-	return rsp.CACertificate, nil
+	return r.CACertificate, errR
 }

card.go

@@ -4,8 +4,6 @@
 package aiven
 
 import (
-	"encoding/json"
-	"errors"
 	"fmt"
 )
 
@@ -38,21 +36,15 @@ type (
 
 // List lists all the cards linked to the authenticated account/
 func (h *CardsHandler) List() ([]*Card, error) {
-	rsp, err := h.client.doGetRequest("/card", nil)
+	bts, err := h.client.doGetRequest("/card", nil)
 	if err != nil {
 		return nil, err
 	}
 
-	var response *CardListResponse
-	if err := json.Unmarshal(rsp, &response); err != nil {
-		return nil, err
-	}
-
-	if len(response.Errors) != 0 {
-		return nil, errors.New(response.Message)
-	}
+	var r CardListResponse
+	errR := checkAPIResponse(bts, &r)
 
-	return response.Cards, nil
+	return r.Cards, errR
 }
 
 // Get card by card id. The id may be either last 4 digits of the card or the actual id

connection_pool.go

@@ -102,5 +102,5 @@ func (h *ConnectionPoolsHandler) Delete(project, serviceName, poolName string) e
 		return err
 	}
 
-	return handleDeleteResponse(bts)
+	return checkAPIResponse(bts, nil)
 }

database.go

@@ -4,8 +4,6 @@
 package aiven
 
 import (
-	"encoding/json"
-	"errors"
 	"fmt"
 )
 
@@ -46,15 +44,11 @@ func (h *DatabasesHandler) Create(project, service string, req CreateDatabaseReq
 		return nil, err
 	}
 
-	rsp, err := handleAPIResponse(bts)
-	if err != nil {
+	errR := checkAPIResponse(bts, nil)
+	if errR != nil {
 		return nil, err
 	}
 
-	if len(rsp.Errors) != 0 {
-		return nil, rsp.Errors[0]
-	}
-
 	db := Database{DatabaseName: req.Database, LcCollate: req.LcCollate, LcType: req.LcType}
 	return &db, nil
 }
@@ -86,7 +80,7 @@ func (h *DatabasesHandler) Delete(project, service, database string) error {
 		return err
 	}
 
-	return handleDeleteResponse(bts)
+	return checkAPIResponse(bts, nil)
 }
 
 // List will fetch all databases for a given service.
@@ -97,14 +91,8 @@ func (h *DatabasesHandler) List(project, service string) ([]*Database, error) {
 		return nil, err
 	}
 
-	var response *DatabaseListResponse
-	if err := json.Unmarshal(rsp, &response); err != nil {
-		return nil, err
-	}
-
-	if len(response.Errors) != 0 {
-		return nil, errors.New(response.Message)
-	}
+	var r DatabaseListResponse
+	errR := checkAPIResponse(rsp, &r)
 
-	return response.Databases, nil
+	return r.Databases, errR
 }

elasticsearch_acls.go

@@ -1,10 +1,5 @@
 package aiven
 
-import (
-	"encoding/json"
-	"errors"
-)
-
 type (
 	// ElasticSearchACLsHandler Aiven go-client handler for Elastisearch ACLs
 	ElasticSearchACLsHandler struct {
@@ -52,7 +47,10 @@ func (h *ElasticSearchACLsHandler) Update(project, service string, req Elasticse
 		return nil, err
 	}
 
-	return h.response(bts)
+	var r ElasticSearchACLResponse
+	errR := checkAPIResponse(bts, &r)
+
+	return &r, errR
 }
 
 // Get gets all existing Elasticsearch ACLs config
@@ -63,27 +61,10 @@ func (h *ElasticSearchACLsHandler) Get(project, service string) (*ElasticSearchA
 		return nil, err
 	}
 
-	return h.response(bts)
-}
-
-// response checks if response fom Aiven API contains any errors
-func (h *ElasticSearchACLsHandler) response(r []byte) (*ElasticSearchACLResponse, error) {
-	var rsp *ElasticSearchACLResponse
-	if err := json.Unmarshal(r, &rsp); err != nil {
-		return nil, err
-	}
-
-	// response cannot be empty
-	if rsp == nil {
-		return nil, ErrNoResponseData
-	}
-
-	// check API response errors
-	if rsp.Errors != nil && len(rsp.Errors) != 0 {
-		return nil, errors.New(rsp.Message)
-	}
+	var r ElasticSearchACLResponse
+	errR := checkAPIResponse(bts, &r)
 
-	return rsp, nil
+	return &r, errR
 }
 
 // Delete subtracts ACL from already existing Elasticsearch ACLs config