Refactor/code improvements (#247)

* Code improvements

* Revert log validation improvement

billing.go

@@ -72,7 +72,7 @@ func (c *Client) CreateBillingPlan(ctx context.Context, plan BillingPlan) (*Crea
 // UpdateBillingPlan updates values inside a billing plan
 // Endpoint: PATCH /v1/payments/billing-plans
 func (c *Client) UpdateBillingPlan(ctx context.Context, planId string, pathValues map[string]map[string]interface{}) error {
-	patchData := []Patch{}
+	var patchData []Patch
 	for path, data := range pathValues {
 		patchData = append(patchData, Patch{
 			Operation: "replace",

client.go

@@ -7,7 +7,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net/http"
 	"net/http/httputil"
 	"time"
@@ -105,14 +104,19 @@ func (c *Client) Send(req *http.Request, v interface{}) error {
 	if err != nil {
 		return err
 	}
-	defer resp.Body.Close()
+	defer func(Body io.ReadCloser) error {
+		return Body.Close()
+	}(resp.Body)
 
 	if resp.StatusCode < 200 || resp.StatusCode > 299 {
 		errResp := &ErrorResponse{Response: resp}
-		data, err = ioutil.ReadAll(resp.Body)
+		data, err = io.ReadAll(resp.Body)
 
 		if err == nil && len(data) > 0 {
-			json.Unmarshal(data, errResp)
+			err := json.Unmarshal(data, errResp)
+			if err != nil {
+				return err
+			}
 		}
 
 		return errResp
@@ -122,8 +126,8 @@ func (c *Client) Send(req *http.Request, v interface{}) error {
 	}
 
 	if w, ok := v.(io.Writer); ok {
-		io.Copy(w, resp.Body)
+		_, err := io.Copy(w, resp.Body)
-		return nil
+		return err
 	}
 
 	return json.NewDecoder(resp.Body).Decode(v)

unit_test.go

@@ -4,7 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"net/http/httptest"
 	"testing"
@@ -536,7 +536,7 @@ func (ts *webprofileTestServer) ServeHTTP(w http.ResponseWriter, r *http.Request
 func (ts *webprofileTestServer) create(w http.ResponseWriter, r *http.Request) {
 	var data map[string]interface{}
 
-	body, err := ioutil.ReadAll(r.Body)
+	body, err := io.ReadAll(r.Body)
 
 	if err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
@@ -572,7 +572,7 @@ func (ts *webprofileTestServer) create(w http.ResponseWriter, r *http.Request) {
 func (ts *webprofileTestServer) createWithoutName(w http.ResponseWriter, r *http.Request) {
 	var data map[string]interface{}
 
-	body, err := ioutil.ReadAll(r.Body)
+	body, err := io.ReadAll(r.Body)
 
 	if err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
@@ -600,7 +600,7 @@ func (ts *webprofileTestServer) createWithoutName(w http.ResponseWriter, r *http
 func (ts *webprofileTestServer) updatevalid(w http.ResponseWriter, r *http.Request) {
 	var data map[string]interface{}
 
-	body, err := ioutil.ReadAll(r.Body)
+	body, err := io.ReadAll(r.Body)
 
 	if err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)

webhooks.go

@@ -6,7 +6,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 )
 
@@ -96,12 +96,12 @@ func (c *Client) VerifyWebhookSignature(ctx context.Context, httpReq *http.Reque
 	// Read the content
 	var bodyBytes []byte
 	if httpReq.Body != nil {
-		bodyBytes, _ = ioutil.ReadAll(httpReq.Body)
+		bodyBytes, _ = io.ReadAll(httpReq.Body)
 	} else {
 		return nil, errors.New("Cannot verify webhook for HTTP Request with empty body.")
 	}
 	// Restore the io.ReadCloser to its original state
-	httpReq.Body = ioutil.NopCloser(bytes.NewBuffer(bodyBytes))
+	httpReq.Body = io.NopCloser(bytes.NewBuffer(bodyBytes))
 
 	verifyRequest := verifyWebhookSignatureRequest{
 		AuthAlgo:         httpReq.Header.Get("PAYPAL-AUTH-ALGO"),