soroban-rpc: add CORS test

cmd/soroban-rpc/internal/test/cors_test.go

@@ -0,0 +1,32 @@
+package test
+
+import (
+	"bytes"
+	"io"
+	"net/http"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+// TestCORS ensures that we receive the correct CORS headers as a response to an HTTP request.
+// Specifically, when we include an Origin header in the request, a soroban-rpc should response
+// with a corresponding Access-Control-Allow-Origin.
+func TestCORS(t *testing.T) {
+	test := NewTest(t)
+
+	request, err := http.NewRequest("POST", test.sorobanRPCURL(), bytes.NewBufferString("{\"jsonrpc\": \"2.0\", \"id\": 1, \"method\": \"getHealth\"}"))
+	require.NoError(t, err)
+	request.Header.Set("Content-Type", "application/json")
+	origin := "testorigin.com"
+	request.Header.Set("Origin", origin)
+
+	var client http.Client
+	response, err := client.Do(request)
+	require.NoError(t, err)
+	_, err = io.ReadAll(response.Body)
+	require.NoError(t, err)
+
+	accessControl := response.Header.Get("Access-Control-Allow-Origin")
+	require.Equal(t, origin, accessControl)
+}