diff --git a/src/Illuminate/Testing/TestResponse.php b/src/Illuminate/Testing/TestResponse.php
index 1d46a0ac5284..b86a91ca7c93 100644
--- a/src/Illuminate/Testing/TestResponse.php
+++ b/src/Illuminate/Testing/TestResponse.php
@@ -264,6 +264,54 @@ public function assertLocation($uri)
         return $this;
     }
 
+    /**
+     * Assert that the response offers a file download.
+     *
+     * @param  string|null  $filename
+     * @return $this
+     */
+    public function assertDownload($filename = null)
+    {
+        $contentDisposition = explode(';', $this->headers->get('content-disposition'));
+
+        if (trim($contentDisposition[0]) !== 'attachment') {
+            PHPUnit::fail(
+                'Response does not offer a file download.'.PHP_EOL.
+                'Disposition ['.trim($contentDisposition[0]).'] found in header, [attachment] expected.'
+            );
+        }
+
+        if (! is_null($filename)) {
+            if (isset($contentDisposition[1]) &&
+                trim(explode('=', $contentDisposition[1])[0]) !== 'filename') {
+                PHPUnit::fail(
+                    'Unsupported Content-Disposition header provided.'.PHP_EOL.
+                    'Disposition ['.trim(explode('=', $contentDisposition[1])[0]).'] found in header, [filename] expected.'
+                );
+            }
+
+            $message = "Expected file [{$filename}] is not present in Content-Disposition header.";
+
+            if (! isset($contentDisposition[1])) {
+                PHPUnit::fail($message);
+            } else {
+                PHPUnit::assertSame(
+                    $filename,
+                    isset(explode('=', $contentDisposition[1])[1])
+                        ? trim(explode('=', $contentDisposition[1])[1])
+                        : '',
+                    $message
+                );
+
+                return $this;
+            }
+        } else {
+            PHPUnit::assertTrue(true);
+
+            return $this;
+        }
+    }
+
     /**
      * Asserts that the response contains the given cookie and equals the optional value.
      *
diff --git a/tests/Testing/TestResponseTest.php b/tests/Testing/TestResponseTest.php
index 4c80d1196c7f..f3bcac9e2f62 100644
--- a/tests/Testing/TestResponseTest.php
+++ b/tests/Testing/TestResponseTest.php
@@ -1190,6 +1190,63 @@ public function testAssertJsonMissingValidationErrorsNestedCustomErrorsName2()
         $testResponse->assertJsonMissingValidationErrors('bar', 'data.errors');
     }
 
+    public function testAssertDownloadOffered()
+    {
+        $files = new Filesystem;
+        $tempDir = __DIR__.'/tmp';
+        $files->makeDirectory($tempDir, 0755, false, true);
+        $files->put($tempDir.'/file.txt', 'Hello World');
+        $testResponse = TestResponse::fromBaseResponse(new Response(
+            $files->get($tempDir.'/file.txt'), 200, [
+                'Content-Disposition' => 'attachment; filename=file.txt',
+            ]
+        ));
+        $testResponse->assertDownload();
+        $files->deleteDirectory($tempDir);
+    }
+
+    public function testAssertDownloadOfferedWithAFileName()
+    {
+        $files = new Filesystem;
+        $tempDir = __DIR__.'/tmp';
+        $files->makeDirectory($tempDir, 0755, false, true);
+        $files->put($tempDir.'/file.txt', 'Hello World');
+        $testResponse = TestResponse::fromBaseResponse(new Response(
+            $files->get($tempDir.'/file.txt'), 200, [
+                'Content-Disposition' => 'attachment; filename = file.txt',
+            ]
+        ));
+        $testResponse->assertDownload('file.txt');
+        $files->deleteDirectory($tempDir);
+    }
+
+    public function testAssertDownloadOfferedWorksWithBinaryFileResponse()
+    {
+        $files = new Filesystem;
+        $tempDir = __DIR__.'/tmp';
+        $files->makeDirectory($tempDir, 0755, false, true);
+        $files->put($tempDir.'/file.txt', 'Hello World');
+        $testResponse = TestResponse::fromBaseResponse(new BinaryFileResponse(
+            $tempDir.'/file.txt', 200, [], true, 'attachment'
+        ));
+        $testResponse->assertDownload('file.txt');
+        $files->deleteDirectory($tempDir);
+    }
+
+    public function testAssertDownloadOfferedFailsWithInlineContentDisposition()
+    {
+        $this->expectException(AssertionFailedError::class);
+        $files = new Filesystem;
+        $tempDir = __DIR__.'/tmp';
+        $files->makeDirectory($tempDir, 0755, false, true);
+        $files->put($tempDir.'/file.txt', 'Hello World');
+        $testResponse = TestResponse::fromBaseResponse(new BinaryFileResponse(
+            $tempDir.'/file.txt', 200, [], true, 'inline'
+        ));
+        $testResponse->assertDownload();
+        $files->deleteDirectory($tempDir);
+    }
+
     public function testMacroable()
     {
         TestResponse::macro('foo', function () {