Replace LayoutMetricFailed in #44

src/Exception/LayoutMetricsFailed.php

-<?php
-/**
- * @license see LICENSE
- */
-
-namespace HeadlessChromium\Exception;
-
-class LayoutMetricsFailed extends \Exception
-{
-
-}

src/PageUtils/PageLayoutMetrics.php

@@ -2,90 +2,64 @@
 
 namespace HeadlessChromium\PageUtils;
 
-use HeadlessChromium\Communication\Response;
-use HeadlessChromium\Communication\ResponseReader;
-use HeadlessChromium\Exception\LayoutMetricsFailed;
+use HeadlessChromium\Exception\CommunicationException;
 
 /**
  * Used to read layout metrics of the page
  * @internal
  */
-class PageLayoutMetrics
+class PageLayoutMetrics extends ResponseWaiter
 {
 
-    /**
-     * @var ResponseReader
-     */
-    protected $responseReader;
-
-    /**
-     * @var Response
-     */
-    protected $response;
-
-    public function __construct(ResponseReader $responseReader)
-    {
-        $this->responseReader = $responseReader;
-    }
-
-    /**
-     * @return $this
-     * @throws LayoutMetricsFailed
-     * @throws \HeadlessChromium\Exception\NoResponseAvailable
-     * @throws \HeadlessChromium\Exception\OperationTimedOut
-     */
-    public function await()
-    {
-        $this->response = $this->responseReader->waitForResponse();
-
-        if (!$this->response->isSuccessful()) {
-            throw new LayoutMetricsFailed('Could not retrieve layout metrics of the page.');
-        }
-
-        return $this;
-    }
-
     /**
      * Returns raw page metrics data
      * @return array
-     * @throws LayoutMetricsFailed
+     * @throws CommunicationException\ResponseHasError
+     * @throws \HeadlessChromium\Exception\NoResponseAvailable
+     * @throws \HeadlessChromium\Exception\OperationTimedOut
      */
     public function getMetrics(): array
     {
-        $response = $this->responseReader->waitForResponse();
+        $response = $this->awaitResponse();
         return $response->getData()['results'];
     }
 
     /**
      * Returns size of scrollable area
      * @return array
-     * @throws LayoutMetricsFailed
+     * @throws CommunicationException\ResponseHasError
+     * @throws \HeadlessChromium\Exception\NoResponseAvailable
+     * @throws \HeadlessChromium\Exception\OperationTimedOut
      */
     public function getContentSize(): array
     {
-        $response = $this->responseReader->waitForResponse();
+        $response = $this->awaitResponse();
         return $response->getResultData('contentSize');
     }
 
     /**
      * Returns metrics relating to the layout viewport
      * @return array
-     * @throws LayoutMetricsFailed
+     * @throws CommunicationException\ResponseHasError
+     * @throws \HeadlessChromium\Exception\NoResponseAvailable
+     * @throws \HeadlessChromium\Exception\OperationTimedOut
      */
     public function getLayoutViewport(): array
     {
-        $response = $this->responseReader->waitForResponse();
+        $response = $this->awaitResponse();
         return $response->getResultData('layoutViewport');
     }
 
     /**
      * Returns metrics relating to the visual viewport
      * @return array
-     * @throws LayoutMetricsFailed
+     * @throws CommunicationException\ResponseHasError
+     * @throws \HeadlessChromium\Exception\NoResponseAvailable
+     * @throws \HeadlessChromium\Exception\OperationTimedOut
      */
     public function getVisualViewport()
     {
-        $response = $this->responseReader->waitForResponse();
+        $response = $this->awaitResponse();
         return $response->getResultData('visualViewport');
     }
 }

src/PageUtils/ResponseWaiter.php

@@ -5,6 +5,7 @@
 
 namespace HeadlessChromium\PageUtils;
 
+use HeadlessChromium\Communication\Response;
 use HeadlessChromium\Communication\ResponseReader;
 use HeadlessChromium\Exception\CommunicationException\ResponseHasError;
 
@@ -16,6 +17,11 @@ class ResponseWaiter
      */
     protected $responseReader;
 
+    /**
+     * @var Response
+     */
+    protected $response;
+
     /**
      * @param ResponseReader $responseReader
      */
@@ -25,6 +31,7 @@ class ResponseWaiter
     }
 
     /**
+     * Chainable wait for response
      * @param $time
      * @throws \HeadlessChromium\Exception\NoResponseAvailable
      * @throws \HeadlessChromium\Exception\OperationTimedOut
@@ -34,15 +41,32 @@ class ResponseWaiter
      */
     public function await(int $time = null)
     {
-        $response = $this->responseReader->waitForResponse($time);
+        $this->response = $this->responseReader->waitForResponse($time);
 
-        if (!$response->isSuccessful()) {
-            throw new ResponseHasError($response->getErrorMessage(true));
+        if (!$this->response->isSuccessful()) {
+            throw new ResponseHasError($this->response->getErrorMessage(true));
         }
 
         return $this;
     }
 
+    /**
+     * Waits for response and return it
+     * @param int|null $time
+     * @return Response
+     * @throws ResponseHasError
+     * @throws \HeadlessChromium\Exception\NoResponseAvailable
+     * @throws \HeadlessChromium\Exception\OperationTimedOut
+     */
+    protected function awaitResponse(int $time = null): Response
+    {
+        if (!$this->response) {
+            $this->await($time);
+        }
+
+        return $this->response;
+    }
+
     /**
      * @return ResponseReader
      */