From 890cbcd6ce7827c37c42c681e52ebd77f98e188e Mon Sep 17 00:00:00 2001
From: Stefano Scafiti <stefano.scafiti96@gmail.com>
Date: Thu, 18 May 2023 16:05:14 +0200
Subject: [PATCH] Forward request context inside webhook handler

---
 webhooks.go      | 13 +++++++------
 webhooks_test.go |  7 ++++---
 2 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/webhooks.go b/webhooks.go
index 172af97..96ce79b 100644
--- a/webhooks.go
+++ b/webhooks.go
@@ -1,6 +1,7 @@
 package gocardless
 
 import (
+	"context"
 	"crypto/hmac"
 	"crypto/sha256"
 	"encoding/hex"
@@ -12,15 +13,15 @@ import (
 
 // EventHandler is the interface that must be implemented to handle events from a webhook.
 type EventHandler interface {
-	HandleEvent(Event) error
+	HandleEvent(context.Context, Event) error
 }
 
 // EventHandlerFunc can be used to convert a function into an EventHandler
-type EventHandlerFunc func(Event) error
+type EventHandlerFunc func(context.Context, Event) error
 
 // HandleEvent will call the EventHandlerFunc function
-func (h EventHandlerFunc) HandleEvent(e Event) error {
-	return h(e)
+func (h EventHandlerFunc) HandleEvent(ctx context.Context, e Event) error {
+	return h(ctx, e)
 }
 
 // WebhookHandler allows you to process incoming events from webhooks.
@@ -43,7 +44,7 @@ func NewWebhookHandler(secret string, h EventHandler) (*WebhookHandler, error) {
 // ServeHTTP processes incoming webhooks and dispatches events to the corresponsing handlers.
 func (h *WebhookHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	sig, err := hex.DecodeString(r.Header.Get("Webhook-Signature"))
-	if len(sig) == 0 {
+	if len(sig) == 0 || err != nil {
 		http.Error(w, "invalid signature", 498)
 		return
 	}
@@ -65,7 +66,7 @@ func (h *WebhookHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	}
 
 	for _, event := range events.Events {
-		err := h.HandleEvent(event)
+		err := h.HandleEvent(r.Context(), event)
 		if err != nil {
 			http.Error(w, err.Error(), http.StatusInternalServerError)
 			return
diff --git a/webhooks_test.go b/webhooks_test.go
index 5e246fe..4005f7e 100644
--- a/webhooks_test.go
+++ b/webhooks_test.go
@@ -1,6 +1,7 @@
 package gocardless
 
 import (
+	"context"
 	"errors"
 	"net/http"
 	"net/http/httptest"
@@ -9,7 +10,7 @@ import (
 )
 
 func TestWebhookFailsWithInvalidSignature(t *testing.T) {
-	wh, err := NewWebhookHandler("testing", EventHandlerFunc(func(e Event) error {
+	wh, err := NewWebhookHandler("testing", EventHandlerFunc(func(ctx context.Context, e Event) error {
 		t.Error("unexpected call")
 		return nil
 	}))
@@ -36,7 +37,7 @@ func TestWebhookFailsWithInvalidSignature(t *testing.T) {
 func TestWebhookFailsWithValidSignature(t *testing.T) {
 	var called int
 
-	wh, err := NewWebhookHandler("testing", EventHandlerFunc(func(e Event) error {
+	wh, err := NewWebhookHandler("testing", EventHandlerFunc(func(ctx context.Context, e Event) error {
 		called++
 		expectedID := "EVTESTNE86TNZS"
 		if e.Id != expectedID {
@@ -72,7 +73,7 @@ func TestWebhookFailsWithValidSignature(t *testing.T) {
 func TestWebhookWhenHandlerFails(t *testing.T) {
 	var called int
 
-	wh, err := NewWebhookHandler("testing", EventHandlerFunc(func(e Event) error {
+	wh, err := NewWebhookHandler("testing", EventHandlerFunc(func(ctx context.Context, e Event) error {
 		called++
 		expectedID := "EVTESTNE86TNZS"
 		if e.Id != expectedID {