Merge pull request #58 from open-sausages/pulls/2.2/pending-requests-…

…awaited

ADD / TestSessionState initial implementation

README.md

@@ -20,6 +20,11 @@ is a random token stored in the browser session, in order to make the
 test session specific to the executing browser, and allow multiple
 people using their own test session in the same webroot.
 
+The module also keeps some metadata about the session state in the database,
+so that it may be available for the clients as well.
+E.g. the silverstripe-behat-extension may use it through this module APIs,
+allowing us to introduce some grey-box testing techniques.
+
 The module also serves as an initializer for the
 [SilverStripe Behat Extension](https://github.com/silverstripe-labs/silverstripe-behat-extension/).
 It is required for Behat because the Behat CLI test runner needs to persist

src/TestSessionEnvironment.php

@@ -335,6 +335,8 @@ public function applyState($state)
                 // Connect to the new database, overwriting the old DB connection (if any)
                 DB::connect($databaseConfig);
             }
+
+            TestSessionState::create()->write();  // initialize the session state
         }
 
         // Mailer
@@ -363,6 +365,7 @@ public function applyState($state)
         }
 
         $this->saveState($state);
+
         $this->extend('onAfterApplyState');
     }
 
@@ -558,4 +561,38 @@ protected function getAssetsBackupfolder()
     {
         return PUBLIC_PATH . DIRECTORY_SEPARATOR . 'assets_backup';
     }
+
+
+    /**
+     * Wait for pending requests
+     *
+     * @param int $await Time to wait (in ms) after the last response (to allow the browser react)
+     * @param int $timeout For how long (in ms) do we wait before giving up
+     *
+     * @return bool Whether there are no more pending requests
+     */
+    public function waitForPendingRequests($await = 700, $timeout = 10000)
+    {
+        $now = static function () {
+            return microtime(true) * 10000;
+        };
+
+        $timeout = $now() + $timeout;
+        $interval = max(300, $await);
+        do {
+            $model = TestSessionState::get()->byID(1);
+
+            $pendingRequests = $model->PendingRequests > 0;
+            $lastRequestAwait = ($model->LastResponseTimestamp + $await) > $now();
+
+            $pending = $pendingRequests || $lastRequestAwait;
+
+            if ($timeout < $now()) {
+                // timed out
+                return false;
+            }
+        } while ($pending && (usleep($interval * 1000) || true));
+
+        return true;
+    }
 }

src/TestSessionHTTPMiddleware.php

@@ -39,12 +39,14 @@ public function process(HTTPRequest $request, callable $delegate)
 
         // Load test state
         $this->loadTestState($request);
+        TestSessionState::incrementState();
 
         // Call with safe teardown
         try {
             return $delegate($request);
         } finally {
             $this->restoreTestState($request);
+            TestSessionState::decrementState();
         }
     }
 

src/TestSessionState.php

@@ -0,0 +1,60 @@
+<?php
+
+namespace SilverStripe\TestSession;
+
+use SilverStripe\ORM\DataObject;
+use SilverStripe\ORM\Queries\SQLUpdate;
+
+/**
+ * The session state keeps some metadata about the current test session.
+ * This may allow the client (Behat) to get some insight into the
+ * server side affairs (e.g. if the server is handling some number requests at the moment).
+ *
+ * The client side (Behat) must not use this class straightforwardly, but rather
+ * rely on the API of {@see TestSessionEnvironment} or {@see TestSessionController}.
+ *
+ * @property int PendingRequests keeps information about how many requests are in progress
+ * @property float LastResponseTimestamp microtime of the last response made by the server
+ */
+class TestSessionState extends DataObject
+{
+    private static $table_name = 'TestSessionState';
+
+    private static $db = [
+        'PendingRequests' => 'Int',
+        'LastResponseTimestamp' => 'Decimal(14, 0)'
+    ];
+
+    /**
+     * Increments TestSessionState.PendingRequests number by 1
+     * to indicate we have one more request in progress
+     */
+    public static function incrementState()
+    {
+        $schema = DataObject::getSchema();
+
+        $update = SQLUpdate::create(sprintf('"%s"', $schema->tableName(self::class)))
+            ->addWhere(['ID' => 1])
+            ->assignSQL('"PendingRequests"', '"PendingRequests" + 1');
+
+        $update->execute();
+    }
+
+    /**
+     * Decrements TestSessionState.PendingRequests number by 1
+     * to indicate we have one more request in progress.
+     * Also updates TestSessionState.LastResponseTimestamp
+     * to the current timestamp.
+     */
+    public static function decrementState()
+    {
+        $schema = DataObject::getSchema();
+
+        $update = SQLUpdate::create(sprintf('"%s"', $schema->tableName(self::class)))
+                ->addWhere(['ID' => 1])
+                ->assignSQL('"PendingRequests"', '"PendingRequests" - 1')
+                ->assign('"LastResponseTimestamp"', microtime(true) * 10000);
+
+        $update->execute();
+    }
+}