screenshot clip + several bugfixes [ci skip]

Author: gsouf

README.md

@@ -61,7 +61,7 @@ to crawl websites... and almost everything that you can do with chrome as a huma
     // get page title
     $pageTitle = $page->evaluate('document.title')->getReturnValue();
 
-    // screenshot - Say "Cheese"!
+    // screenshot - Say "Cheese"! 😄
     $page->screenshot()->saveToFile('/foo/bar.png');
 
     // bye

src/Communication/ResponseReader.php

@@ -6,6 +6,8 @@
 namespace HeadlessChromium\Communication;
 
 use HeadlessChromium\Exception\NoResponseAvailable;
+use HeadlessChromium\Utils;
+use HeadlessChromium\Exception\OperationTimedOut;
 
 class ResponseReader
 {
@@ -75,7 +77,7 @@ public function getConnection(): Connection
     public function getResponse(): Response
     {
         if (!$this->response) {
-            throw new NoResponseAvailable('Response is not available');
+            throw new NoResponseAvailable('Response is not available. Try to use the method waitForResponse instead.');
         }
 
         return $this->response;
@@ -84,26 +86,37 @@ public function getResponse(): Response
     /**
      * Wait for a response
      * @param int $timeout time to wait for a response (milliseconds)
-     * @return Response|null the response or null if no responses were found before the given timeout is reached
+     * @return Response
+     *
+     * @throws NoResponseAvailable
+     * @throws OperationTimedOut
      */
-    public function waitForResponse(int $timeout = null)
+    public function waitForResponse(int $timeout = null): Response
     {
-
         if ($this->hasResponse()) {
             return $this->getResponse();
         }
 
         // default 2000ms
         $timeout = $timeout ?? 2000;
 
-        // 10 microseconds between each iteration
-        $tryDelay = 10;
+        // TODO replace with Utils::tryWithTimeout
+        return Utils::tryWithTimeout($timeout * 1000, $this->waitForResponseGenerator());
+    }
+
+    /**
+     * To be used in waitForResponse method
+     * @return \Generator|Response
+     * @throws NoResponseAvailable
+     * @internal
+     */
+    private function waitForResponseGenerator()
+    {
+        while (true) {
 
-        // time to wait for the response
-        $waitUntil = microtime(true) + $timeout / 1000;
+            // 50 microseconds between each iteration
+            $tryDelay = 50;
 
-        // TODO replace with Utils::tryWithTimeout
-        do {
             // read available response
             $hasResponse = $this->checkForResponse();
 
@@ -113,10 +126,8 @@ public function waitForResponse(int $timeout = null)
             }
 
             // wait before next check
-            usleep($tryDelay);
-        } while (microtime(true) < $waitUntil);
-
-        return null;
+            yield $tryDelay;
+        }
     }
 
     /**

src/Exception/JavascriptException.php

@@ -0,0 +1,12 @@
+<?php
+/**
+ * @license see LICENSE
+ */
+
+namespace HeadlessChromium\Exception;
+
+
+class JavascriptException extends \Exception
+{
+
+}

src/Page.php

@@ -182,6 +182,12 @@ public function screenshot(array $options = []): PageScreenshot
             $screenshotOptions['quality'] = $options['quality'];
         }
 
+        // TODO document clip
+        // TODO validate clip/use viewport object
+        if (array_key_exists('clip', $options)) {
+            $screenshotOptions['clip'] = $options['clip'];
+        }
+
         // request screen shot
         $responseReader = $this->getSession()
             ->sendMessage(new Message('Page.captureScreenshot', $screenshotOptions));

src/PageEvaluation.php

@@ -8,6 +8,7 @@
 use HeadlessChromium\Communication\Response;
 use HeadlessChromium\Communication\ResponseReader;
 use HeadlessChromium\Exception\EvaluationFailed;
+use HeadlessChromium\Exception\JavascriptException;
 
 /**
  * Used to read data from page evaluation response
@@ -41,13 +42,20 @@ public function __construct(ResponseReader $responseReader)
      */
     public function waitForResponse()
     {
-        $response = $this->responseReader->waitForResponse();
+        $this->response = $this->responseReader->waitForResponse();
 
         if (!$this->response->isSuccessful()) {
             throw new EvaluationFailed('Could not evaluate the script in the page.');
         }
 
-        $this->response = $response;
+        $result = $this->response->getResultData('result');
+
+        $resultSubType = $result['subtype'] ?? null;
+
+        if ($resultSubType == 'error') {
+            // TODO dump javascript trace
+            throw new JavascriptException('Error during javascript evaluation: ' . $result['description']);
+        }
 
         return $this;
     }
@@ -63,7 +71,7 @@ public function getReturnValue()
             $this->waitForResponse();
         }
 
-        return $this->response->getResultData('value');
+        return $this->response->getResultData('result')['value'] ?? null;
     }
 
     /**
@@ -77,6 +85,6 @@ public function getReturnType()
             $this->waitForResponse();
         }
 
-        return $this->response->getResultData('type');
+        return $this->response->getResultData('result')['type'] ?? null;
     }
 }

src/PageScreenshot.php

@@ -71,10 +71,18 @@ public function saveToFile(string $path)
         }
 
         // save screenshot
-        if (!is_writable($path)) {
-            throw new FilesystemException(
-                sprintf('The file %s is not writable.', $path)
-            );
+        if (file_exists($path)) {
+            if (!is_writable($path)) {
+                throw new FilesystemException(
+                    sprintf('The file %s is not writable.', $path)
+                );
+            }
+        } else {
+            if (!touch($path)) {
+                throw new FilesystemException(
+                    sprintf('The file %s could not be created.', $path)
+                );
+            }
         }
 
         $file = fopen($path, 'wb');