complete the test case for signature

src/PayPalSignatureValidator.php

@@ -40,7 +40,7 @@ public function isValid(Request $request, WebhookConfig $config): bool
                     ]),
                     signature: base64_decode($request->header('PAYPAL-TRANSMISSION-SIG')),
                     public_key: openssl_pkey_get_public($this->downloadCert($request->header('PAYPAL-CERT-URL'))),
-                    algorithm: 'sha256WithRSAEncryption'
+                    algorithm: OPENSSL_ALGO_SHA256
                 ) === 1;
         } catch (RequestException $e) {
             throw $e;

tests/Factory/PayPalWebhookFactory.php

@@ -5,13 +5,13 @@
 
 class PayPalWebhookFactory
 {
-    public function getCheckoutOrderApproved(): array
+    public static function checkoutOrderApproved(): array
     {
         $body = file_get_contents(__DIR__.'/Messages/checkout_order_approved.json');
         return json_decode($body, true);
     }
 
-    public function getCheckoutOrderCompleted(): array
+    public static function checkoutOrderCompleted(): array
     {
         $body = file_get_contents(__DIR__.'/Messages/checkout_order_completed.json');
         return json_decode($body, true);

tests/Factory/PaypalRequestFactory.php

@@ -0,0 +1,67 @@
+<?php
+declare(strict_types=1);
+
+namespace Ankurk91\PayPalWebhooks\Tests\Factory;
+
+use Illuminate\Http\Request;
+use Illuminate\Support\Str;
+
+class PaypalRequestFactory
+{
+    /**
+     * The certificate to sign the request.
+     */
+    protected ?string $certificate;
+
+    protected function getSignature(string $stringToSign): string
+    {
+        $privateKey = openssl_pkey_new();
+
+        // Export certificate for later use
+        $csr = openssl_csr_new([], $privateKey);
+        $x509 = openssl_csr_sign($csr, null, $privateKey, 1);
+        openssl_x509_export($x509, $this->certificate);
+
+        openssl_sign($stringToSign, $signature, $privateKey, OPENSSL_ALGO_SHA256);
+
+        return base64_encode($signature);
+    }
+
+    public function getCertificate(): ?string
+    {
+        return $this->certificate;
+    }
+
+    public function make(string $webhookId): Request
+    {
+        $payload = PayPalWebhookFactory::checkoutOrderApproved();
+        $request = Request::create('/webhooks/paypal', 'POST', [], [], [], [], json_encode($payload));
+
+        $headers = [
+            'PAYPAL-TRANSMISSION-ID' => Str::random(),
+            'PAYPAL-TRANSMISSION-TIME' => now()->toDateTimeString(),
+            'PAYPAL-CERT-URL' => 'https://sandbox.paypal.com/cert.pem',
+        ];
+
+        foreach ($headers as $name => $value) {
+            $request->headers->set($name, $value);
+        }
+
+        $request->headers->set(
+            'PAYPAL-TRANSMISSION-SIG',
+            $this->getSignature($this->getStringToSign($request, $webhookId))
+        );
+
+        return $request;
+    }
+
+    protected function getStringToSign(Request $request, string $webhookID): string
+    {
+        return implode('|', [
+            $request->header('PAYPAL-TRANSMISSION-ID'),
+            $request->header('PAYPAL-TRANSMISSION-TIME'),
+            $webhookID,
+            crc32($request->getContent()),
+        ]);
+    }
+}

tests/PayPalSignatureValidatorTest.php

@@ -5,6 +5,8 @@
 
 use Ankurk91\PayPalWebhooks\PayPalSignatureValidator;
 use Ankurk91\PayPalWebhooks\PayPalWebhookConfig;
+use Ankurk91\PayPalWebhooks\Tests\Factory\PaypalRequestFactory;
+use Illuminate\Support\Facades\Http;
 use Spatie\WebhookClient\WebhookConfig;
 
 class PayPalSignatureValidatorTest extends TestCase
@@ -23,9 +25,27 @@ public function setUp(): void
         $this->validator = new PayPalSignatureValidator();
     }
 
-    public function testValidSignature(): void
+    public function test_passes_for_valid_signature(): void
     {
-        $this->markTestSkipped('Should we ask ChatGPT to write tests?.');
+        $factory = new PaypalRequestFactory();
+
+        $request = $factory->make($this->webhookID);
+
+        Http::fake([
+            'paypal.com/*' => Http::response($factory->getCertificate())
+        ]);
+
+        $this->assertTrue($this->validator->isValid($request, $this->config));
+    }
+
+    public function test_failed_on_invalid_signature_url()
+    {
+        $factory = new PaypalRequestFactory();
+
+        $request = $factory->make($this->webhookID);
+        $request->headers->set('PAYPAL-CERT-URL', 'https://example.com/cert.pem');
+
+        $this->assertFalse($this->validator->isValid($request, $this->config));
     }
 
 }

tests/PayPalWebhookIntegrationTest.php

@@ -32,8 +32,7 @@ public function test_it_can_processes_webhook_successfully()
         Event::fake();
         Bus::fake(TestHandlerJob::class);
 
-        $messageFactory = new PayPalWebhookFactory();
-        $payload = $messageFactory->getCheckoutOrderApproved();
+        $payload = PayPalWebhookFactory::checkoutOrderApproved();
 
         $this->postJson('/webhooks/paypal', $payload)
             ->assertSuccessful();
@@ -57,8 +56,7 @@ public function test_it_fails_when_invalid_job_class_configured()
     {
         Event::fake();
 
-        $messageFactory = new PayPalWebhookFactory();
-        $payload = $messageFactory->getCheckoutOrderCompleted();
+        $payload = PayPalWebhookFactory::checkoutOrderCompleted();
 
         $this->postJson('/webhooks/paypal', $payload)
             ->assertSuccessful();
@@ -78,8 +76,7 @@ public function test_it_fails_when_invalid_job_class_configured()
 
     public function test_it_process_same_webhook_only_once()
     {
-        $messageFactory = new PayPalWebhookFactory();
-        $payload = $messageFactory->getCheckoutOrderApproved();
+        $payload = PayPalWebhookFactory::checkoutOrderApproved();
 
         $this->postJson('/webhooks/paypal', $payload)
             ->assertSuccessful();