Allow using an env var to determine chrome driver binary (#49)

* Allow using an env var to determine chrome driver binary

* Added small documentation to use the PANTHERE_CHROME_DRIVER_BINARY env var

Author: Pierstoval

README.md

@@ -145,6 +145,7 @@ The following environment variables can be set to change some Panthère behavior
 * `PANTHERE_NO_HEADLESS`: to disable browsers's headless mode (will display the testing window, useful to debug)
 * `PANTHERE_NO_SANDBOX`: to disable [Chrome's sandboxing](https://chromium.googlesource.com/chromium/src/+/b4730a0c2773d8f6728946013eb812c6d3975bec/docs/design/sandbox.md) (unsafe, but allows to use Panthère in containers)
 * `PANTHERE_WEB_SERVER_DIR`: to change the project's document root (default to `public/`)
+* `PANTHERE_CHROME_DRIVER_BINARY`: to use another `chromedriver` binary, instead of relying on the ones already provided by Panthère
 
 ## Docker Integration
 

src/ProcessManager/ChromeManager.php

@@ -32,7 +32,7 @@ final class ChromeManager implements BrowserManagerInterface
 
     public function __construct(?string $chromeDriverBinary = null, ?array $arguments = null, array $options = [])
     {
-        $this->process = new Process([$chromeDriverBinary ?? $this->findChromeDriverBinary()], null, null, null, null);
+        $this->process = new Process([$chromeDriverBinary ?: $this->findChromeDriverBinary()], null, null, null, null);
         $this->arguments = $arguments ?? $this->getDefaultArguments();
         $this->options = \array_merge($this->getDefaultOptions(), $options);
     }
@@ -66,6 +66,10 @@ public function quit(): void
 
     private function findChromeDriverBinary(): string
     {
+        if ($binary = $_SERVER['PANTHERE_CHROME_DRIVER_BINARY'] ?? null) {
+            return $binary;
+        }
+
         switch (PHP_OS_FAMILY) {
             case 'Windows':
                 return __DIR__.'/../../chromedriver-bin/chromedriver.exe';