Added constraints for session

src/TestSuite/Constraint/Session/SessionEquals.php

@@ -0,0 +1,80 @@
+<?php
+/**
+ * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
+ * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
+ *
+ * Licensed under The MIT License
+ * For full copyright and license information, please see the LICENSE.txt
+ * Redistributions of files must retain the above copyright notice
+ *
+ * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
+ * @since         3.7.0
+ * @license       http://www.opensource.org/licenses/mit-license.php MIT License
+ */
+namespace Cake\TestSuite\Constraint\Session;
+
+use PHPUnit\Framework\AssertionFailedError;
+use PHPUnit\Framework\Constraint\Constraint;
+
+/**
+ * SessionEquals
+ */
+class SessionEquals extends Constraint
+{
+
+    /**
+     * @var \Cake\Http\Session
+     */
+    protected $session;
+
+    /**
+     * @var string
+     */
+    protected $path;
+
+    /**
+     * @var mixed
+     */
+    protected $value;
+
+    /**
+     * Constructor
+     *
+     * @param \Cake\Http\Session $session Session
+     * @param string $path Session Path
+     */
+    public function __construct($session, $path)
+    {
+        parent::__construct();
+
+        if (!$session) {
+            throw new AssertionFailedError('There is no stored session data. Perhaps you need to run a request?');
+        }
+
+        $this->session = $session;
+        $this->path = $path;
+    }
+
+    /**
+     * Compare session value
+     *
+     * @param mixed $other Value to compare with
+     * @return bool
+     */
+    public function matches($other)
+    {
+        $this->value = $this->session->read($this->path);
+
+        return $this->value === $other;
+    }
+
+    /**
+     * Assertion message
+     *
+     * @return string
+     */
+    public function toString()
+    {
+        return sprintf('was in path `%s`, found "%s" instead', $this->path, $this->value);
+    }
+}

src/TestSuite/IntegrationTestTrait.php

@@ -30,6 +30,7 @@
 use Cake\TestSuite\Constraint\Response\StatusFailure;
 use Cake\TestSuite\Constraint\Response\StatusOk;
 use Cake\TestSuite\Constraint\Response\StatusSuccess;
+use Cake\TestSuite\Constraint\Session\SessionEquals;
 use Cake\TestSuite\Constraint\View\TemplateFileEquals;
 use Cake\TestSuite\Constraint\View\LayoutFileEquals;
 use Cake\TestSuite\Stub\TestExceptionRenderer;
@@ -1006,15 +1007,7 @@ public function assertLayout($content, $message = '')
      */
     public function assertSession($expected, $path, $message = '')
     {
-        if (empty($this->_requestSession)) {
-            $this->fail('There is no stored session data. Perhaps you need to run a request?');
-        }
-        $result = $this->_requestSession->read($path);
-        $this->assertEquals(
-            $expected,
-            $result,
-            'Session content for "' . $path . '" differs. ' . $message
-        );
+        $this->assertThat($expected, new SessionEquals($this->_requestSession, $path), $message);
     }
 
     /**