feature #176 Check if the installer has enough permissions *before* downloading the file (javiereguiluz)

This PR was squashed before being merged into the 1.0-dev branch (closes #176).

Discussion
----------

Check if the installer has enough permissions *before* downloading the file

This fixes #175

Commits
-------

478b09e Check if the installer has enough permissions *before* downloading the file

Author: javiereguiluz

src/Symfony/Installer/DemoCommand.php

@@ -62,6 +62,7 @@ protected function execute(InputInterface $input, OutputInterface $output)
         try {
             $this
                 ->checkProjectName()
+                ->checkPermissions()
                 ->download()
                 ->extract()
                 ->cleanUp()

src/Symfony/Installer/DownloadCommand.php

@@ -24,6 +24,7 @@
 use Symfony\Component\Console\Helper\ProgressBar;
 use Symfony\Component\Console\Input\InputInterface;
 use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\Filesystem\Exception\IOException;
 use Symfony\Component\Filesystem\Filesystem;
 use Symfony\Component\Intl\Exception\MethodArgumentValueNotImplementedException;
 use Symfony\Installer\Exception\AbortException;
@@ -299,6 +300,20 @@ protected function createGitIgnore()
         return $this;
     }
 
+    /**
+     * Checks if the installer has enough permissions to create the project.
+     */
+    protected function checkPermissions()
+    {
+        $projectParentDirectory = dirname($this->projectDir);
+
+        if (!is_writable($projectParentDirectory)) {
+            throw new IOException(sprintf('Installer does not have enough permissions to write to the "%s" directory.', $projectParentDirectory));
+        }
+
+        return $this;
+    }
+
     /**
      * Utility method to show the number of bytes in a readable format.
      *
@@ -334,7 +349,7 @@ protected function getErrorMessage(\Requirement $requirement, $lineSize = 70)
             return;
         }
 
-        $errorMessage  = wordwrap($requirement->getTestMessage(), $lineSize - 3, PHP_EOL.'   ').PHP_EOL;
+        $errorMessage = wordwrap($requirement->getTestMessage(), $lineSize - 3, PHP_EOL.'   ').PHP_EOL;
         $errorMessage .= '   > '.wordwrap($requirement->getHelpText(), $lineSize - 5, PHP_EOL.'   > ').PHP_EOL;
 
         return $errorMessage;

src/Symfony/Installer/NewCommand.php

@@ -54,6 +54,7 @@ protected function execute(InputInterface $input, OutputInterface $output)
             $this
                 ->checkProjectName()
                 ->checkSymfonyVersionIsInstallable()
+                ->checkPermissions()
                 ->download()
                 ->extract()
                 ->cleanUp()