[9.x] Add streamed content test assertion (#45298)

* assert streamed content

* add missing ns

* fix test issues

Author: ziadoz

src/Illuminate/Testing/TestResponse.php

@@ -572,6 +572,19 @@ public function assertContent($value)
         return $this;
     }
 
+    /**
+     * Assert that the given string matches the streamed response content.
+     *
+     * @param  $value
+     * @return $this
+     */
+    public function assertStreamedContent($value)
+    {
+        PHPUnit::assertSame($value, $this->streamedContent());
+
+        return $this;
+    }
+
     /**
      * Assert that the given string or array of strings are contained within the response.
      *

tests/Testing/TestResponseTest.php

@@ -28,6 +28,7 @@
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\HttpFoundation\BinaryFileResponse;
 use Symfony\Component\HttpFoundation\Cookie;
+use Symfony\Component\HttpFoundation\StreamedResponse;
 
 class TestResponseTest extends TestCase
 {
@@ -234,6 +235,34 @@ public function testAssertContent()
         }
     }
 
+    public function testAssertStreamedContent()
+    {
+        $response = TestResponse::fromBaseResponse(
+            new StreamedResponse(function () {
+                $stream = fopen('php://memory', 'r+');
+                fwrite($stream, 'expected response data');
+                rewind($stream);
+                fpassthru($stream);
+            })
+        );
+
+        $response->assertStreamedContent('expected response data');
+
+        try {
+            $response->assertStreamedContent('expected');
+            $this->fail('xxxx');
+        } catch (AssertionFailedError $e) {
+            $this->assertSame('Failed asserting that two strings are identical.', $e->getMessage());
+        }
+
+        try {
+            $response->assertStreamedContent('expected response data with extra');
+            $this->fail('xxxx');
+        } catch (AssertionFailedError $e) {
+            $this->assertSame('Failed asserting that two strings are identical.', $e->getMessage());
+        }
+    }
+
     public function testAssertSee()
     {
         $response = $this->makeMockResponse([