From 6eed01221b939e8e29fc0ad94f4b0cc6ff2ba7a5 Mon Sep 17 00:00:00 2001
From: Ryan <ryanford@poluglottos.com>
Date: Fri, 16 Jun 2023 11:48:52 +0200
Subject: [PATCH] feat(gateway): adding CORS to gateway

---
 api/gateway/middleware.go  |  8 ++++++++
 api/gateway/server_test.go | 31 +++++++++++++++++++++++++++++--
 2 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/api/gateway/middleware.go b/api/gateway/middleware.go
index 498b9c5d64..2c88b34185 100644
--- a/api/gateway/middleware.go
+++ b/api/gateway/middleware.go
@@ -18,9 +18,17 @@ func (h *Handler) RegisterMiddleware(srv *Server) {
 		setContentType,
 		checkPostDisabled(h.state),
 		wrapRequestContext,
+		enableCors,
 	)
 }
 
+func enableCors(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Access-Control-Allow-Origin", "*")
+		next.ServeHTTP(w, r)
+	})
+}
+
 func setContentType(next http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Add("Content-Type", "application/json")
diff --git a/api/gateway/server_test.go b/api/gateway/server_test.go
index e98d7a6091..cb8e3d17ae 100644
--- a/api/gateway/server_test.go
+++ b/api/gateway/server_test.go
@@ -12,8 +12,12 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
+const (
+	address = "localhost"
+	port    = "0"
+)
+
 func TestServer(t *testing.T) {
-	address, port := "localhost", "0"
 	server := NewServer(address, port)
 
 	ctx, cancel := context.WithCancel(context.Background())
@@ -42,10 +46,33 @@ func TestServer(t *testing.T) {
 	require.NoError(t, err)
 }
 
+func TestCorsEnabled(t *testing.T) {
+	server := NewServer(address, port)
+	server.RegisterMiddleware(enableCors)
+
+	ctx, cancel := context.WithCancel(context.Background())
+	t.Cleanup(cancel)
+
+	err := server.Start(ctx)
+	require.NoError(t, err)
+
+	// register ping handler
+	ping := new(ping)
+	server.RegisterHandlerFunc("/ping", ping.ServeHTTP, http.MethodGet)
+
+	url := fmt.Sprintf("http://%s/ping", server.ListenAddr())
+
+	resp, err := http.Get(url)
+	require.NoError(t, err)
+	defer resp.Body.Close()
+
+	require.NoError(t, err)
+	require.Equal(t, resp.Header.Get("Access-Control-Allow-Origin"), "*")
+}
+
 // TestServer_contextLeakProtection tests to ensure a context
 // deadline was added by the context wrapper middleware server-side.
 func TestServer_contextLeakProtection(t *testing.T) {
-	address, port := "localhost", "0"
 	server := NewServer(address, port)
 	server.RegisterMiddleware(wrapRequestContext)