Use new struct to check status & Remove IAP_ENVIRONMENT

Use a new struct called `HttpStatusResponse` to check the status code returned in the receipt. This is ios-type independent and will redirect the receipt to sandbox if needed.

Following Apple's recommendation, always hit production and then sandbox. There is no more need to specify which environment to hit.

appstore/model.go

@@ -102,7 +102,7 @@ type (
 	// We defined each field by the current IAP response, but some fields are not mentioned
 	// in the following Apple's document;
 	// https://developer.apple.com/library/ios/releasenotes/General/ValidateAppStoreReceipt/Chapters/ReceiptFields.html
-	// If you get other types or fileds from the IAP response, you should use the struct you defined.
+	// If you get other types or fields from the IAP response, you should use the struct you defined.
 	IAPResponse struct {
 		Status             int                  `json:"status"`
 		Environment        string               `json:"environment"`
@@ -112,4 +112,10 @@ type (
 		PendingRenewalInfo []PendingRenewalInfo `json:"pending_renewal_info"`
 		IsRetryable        bool                 `json:"is-retryable"`
 	}
+
+	// The HttpStatusResponse struct contains the status code returned by the store
+	// Used as a workaround to detect when to hit the production appstore or sandbox appstore regardless of receipt type
+	HttpStatusResponse struct {
+		Status int `json:"status"`
+	}
 )

appstore/validator.go

@@ -5,7 +5,6 @@ import (
 	"encoding/json"
 	"errors"
 	"net/http"
-	"os"
 	"time"
 )
 
@@ -18,7 +17,6 @@ const (
 
 // Config is a configuration to initialize client
 type Config struct {
-	IsProduction bool
 	TimeOut time.Duration
 }
 
@@ -29,9 +27,9 @@ type IAPClient interface {
 
 // Client implements IAPClient
 type Client struct {
-	URL     string
-	TimeOut time.Duration
+	ProductionURL string
 	SandboxURL    string
+	TimeOut       time.Duration
 }
 
 // HandleError returns error message by status code
@@ -80,12 +78,9 @@ func HandleError(status int) error {
 // New creates a client object
 func New() Client {
 	client := Client{
-		URL:     SandboxURL,
-		TimeOut: time.Second * 5,
+		ProductionURL: ProductionURL,
 		SandboxURL:    SandboxURL,
-	}
-	if os.Getenv("IAP_ENVIRONMENT") == "production" {
-		client.URL = ProductionURL
+		TimeOut:       time.Second * 5,
 	}
 	return client
 }
@@ -97,12 +92,10 @@ func NewWithConfig(config Config) Client {
 	}
 
 	client := Client{
-		URL:     SandboxURL,
+		ProductionURL: ProductionURL,
+		SandboxURL:    SandboxURL,
 		TimeOut:       config.TimeOut,
 	}
-	if config.IsProduction {
-		client.URL = ProductionURL
-	}
 
 	return client
 }
@@ -116,7 +109,7 @@ func (c *Client) Verify(req IAPRequest, result interface{}) error {
 	b := new(bytes.Buffer)
 	json.NewEncoder(b).Encode(req)
 
-	resp, err := client.Post(c.URL, "application/json; charset=utf-8", b)
+	resp, err := client.Post(c.ProductionURL, "application/json; charset=utf-8", b)
 	if err != nil {
 		return err
 	}
@@ -127,11 +120,8 @@ func (c *Client) Verify(req IAPRequest, result interface{}) error {
 		return err
 	}
 
-	// Always verify your receipt first with the production URL; proceed to verify with the sandbox URL if you receive
-	// a 21007 status code
-	//
 	// https://developer.apple.com/library/content/technotes/tn2413/_index.html#//apple_ref/doc/uid/DTS40016228-CH1-RECEIPTURL
-	r, ok := result.(*IAPResponse)
+	r, ok := result.(*HttpStatusResponse)
 	if ok && r.Status == 21007 {
 		b = new(bytes.Buffer)
 		json.NewEncoder(b).Encode(req)

appstore/validator_test.go

@@ -2,12 +2,12 @@ package appstore
 
 import (
 	"errors"
+	"net/http"
+	"net/http/httptest"
 	"os"
 	"reflect"
 	"testing"
 	"time"
-	"net/http/httptest"
-	"net/http"
 )
 
 func TestHandleError(t *testing.T) {
@@ -93,9 +93,9 @@ func TestHandleError(t *testing.T) {
 
 func TestNew(t *testing.T) {
 	expected := Client{
-		URL:     SandboxURL,
+		ProductionURL: SandboxURL,
 		TimeOut:       time.Second * 5,
-		SandboxURL:SandboxURL,
+		SandboxURL:    SandboxURL,
 	}
 
 	actual := New()
@@ -106,9 +106,9 @@ func TestNew(t *testing.T) {
 
 func TestNewWithEnvironment(t *testing.T) {
 	expected := Client{
-		URL:     ProductionURL,
+		ProductionURL: ProductionURL,
 		TimeOut:       time.Second * 5,
-		SandboxURL:SandboxURL,
+		SandboxURL:    SandboxURL,
 	}
 
 	os.Setenv("IAP_ENVIRONMENT", "production")
@@ -122,12 +122,11 @@ func TestNewWithEnvironment(t *testing.T) {
 
 func TestNewWithConfig(t *testing.T) {
 	config := Config{
-		IsProduction: true,
 		TimeOut: time.Second * 2,
 	}
 
 	expected := Client{
-		URL:     ProductionURL,
+		ProductionURL: ProductionURL,
 		TimeOut:       time.Second * 2,
 	}
 
@@ -138,12 +137,10 @@ func TestNewWithConfig(t *testing.T) {
 }
 
 func TestNewWithConfigTimeout(t *testing.T) {
-	config := Config{
-		IsProduction: true,
-	}
+	config := Config{}
 
 	expected := Client{
-		URL:     ProductionURL,
+		ProductionURL: ProductionURL,
 		TimeOut:       time.Second * 5,
 	}
 
@@ -169,7 +166,7 @@ func TestVerifyTimeout(t *testing.T) {
 
 func TestVerifyBadURL(t *testing.T) {
 	client := New()
-	client.URL = "127.0.0.1"
+	client.ProductionURL = "127.0.0.1"
 
 	req := IAPRequest{
 		ReceiptData: "dummy data",
@@ -186,7 +183,7 @@ func TestVerifyBadPayload(t *testing.T) {
 	defer s.Close()
 
 	client := New()
-	client.URL = s.URL
+	client.ProductionURL = s.URL
 	expected := &IAPResponse{
 		Status: 21002,
 	}
@@ -209,7 +206,7 @@ func TestVerifyBadResponse(t *testing.T) {
 	defer s.Close()
 
 	client := New()
-	client.URL = s.URL
+	client.ProductionURL = s.URL
 	req := IAPRequest{
 		ReceiptData: "dummy data",
 	}
@@ -229,7 +226,7 @@ func TestVerifySandboxReceipt(t *testing.T) {
 	defer sandboxServ.Close()
 
 	client := New()
-	client.URL = s.URL
+	client.ProductionURL = s.URL
 	client.TimeOut = time.Second * 100
 	client.SandboxURL = sandboxServ.URL
 
@@ -255,7 +252,7 @@ func TestVerifySandboxReceiptFailure(t *testing.T) {
 	defer s.Close()
 
 	client := New()
-	client.URL = s.URL
+	client.ProductionURL = s.URL
 	client.TimeOut = time.Second * 100
 	client.SandboxURL = "localhost"