Add config validation for xml configurations

On every run the xml configuration is validated against
the .xsd file. Every validation error will be echoed
as warning.

Author: sebastianfeldmann

build.xml

@@ -89,6 +89,9 @@
 
     <exec executable="${basedir}/build/phar-manifest.php" output="${basedir}/build/phar/manifest.txt"/>
 
+    <!-- Copy .xsd for config validation -->
+    <copy file="${basedir}/phpbu.xsd" tofile="${basedir}/build/phar/phpbu.xsd"/>
+
     <!-- SF/CLI -->
     <copy file="${basedir}/vendor/sebastianfeldmann/cli/LICENSE" tofile="${basedir}/build/phar/lib/sf-cli/LICENSE"/>
     <copy todir="${basedir}/build/phar/lib/sf-cli">

src/Cmd.php

@@ -186,11 +186,25 @@ protected function findConfiguration() : string
      * @return \phpbu\App\Configuration
      * @throws \phpbu\App\Exception
      */
-    protected function createConfiguration(string $configurationFile, Factory $factory)
+    protected function createConfiguration(string $configurationFile, Factory $factory) : Configuration
     {
         // setup bootstrapper with --bootstrap option that has precedence over the config file value
         $bootstrapper  = new Bootstrapper(Arr::getValue($this->arguments, 'bootstrap', ''));
         $configLoader  = Configuration\Loader\Factory::createLoader($configurationFile, $bootstrapper);
+
+        if ($configLoader->hasValidationErrors()) {
+            echo "  Warning - The configuration file did not pass validation!" . \PHP_EOL .
+                 "  The following problems have been detected:" . \PHP_EOL;
+
+            foreach ($configLoader->getValidationErrors() as $line => $errors) {
+                echo \sprintf("\n  Line %d:\n", $line);
+                foreach ($errors as $msg) {
+                    echo \sprintf("  - %s\n", $msg);
+                }
+            }
+            echo \PHP_EOL;
+        }
+
         $configuration = $configLoader->getConfiguration($factory);
 
         // command line arguments overrule the config file settings
@@ -265,7 +279,7 @@ protected function handleSelfUpdate()
             unset($phar);
             // replace current phar with the new one
             rename($tempFilename, $localFilename);
-        } catch (Exception $e) {
+        } catch (\Exception $e) {
             // cleanup crappy phar
             unlink($tempFilename);
             echo 'failed' . PHP_EOL . $e->getMessage() . PHP_EOL;

src/Configuration/Loader.php

@@ -1,6 +1,7 @@
 <?php
 namespace phpbu\App\Configuration;
 
+use phpbu\App\Configuration;
 use phpbu\App\Factory;
 
 /**
@@ -22,5 +23,19 @@ interface Loader
      * @param  \phpbu\App\Factory $factory
      * @return \phpbu\App\Configuration
      */
-    public function getConfiguration(Factory $factory);
+    public function getConfiguration(Factory $factory) : Configuration;
+
+    /**
+     * Is the configuration valid
+     *
+     * @return bool
+     */
+    public function hasValidationErrors() : bool;
+
+    /**
+     * Return a list of all validation errors
+     *
+     * @return array
+     */
+    public function getValidationErrors() : array;
 }

src/Configuration/Loader/File.php

@@ -41,6 +41,13 @@ abstract class File
      */
     protected $bootstrapper;
 
+    /**
+     * List of validation errors
+     *
+     * @var array
+     */
+    protected $errors = [];
+
     /**
      * File constructor
      *
@@ -53,14 +60,34 @@ public function __construct(string $file, Configuration\Bootstrapper $bootstrapp
         $this->bootstrapper = $bootstrapper;
     }
 
+    /**
+     * Is the configuration valid
+     *
+     * @return bool
+     */
+    public function hasValidationErrors(): bool
+    {
+        return \count($this->errors) > 0;
+    }
+
+    /**
+     * Return a list of all validation errors
+     *
+     * @return array
+     */
+    public function getValidationErrors(): array
+    {
+        return $this->errors;
+    }
+
     /**
      * Returns the phpbu Configuration
      *
      * @param  \phpbu\App\Factory $factory
      * @return \phpbu\App\Configuration
      * @throws \phpbu\App\Exception
      */
-    public function getConfiguration(AppFactory $factory)
+    public function getConfiguration(AppFactory $factory) : Configuration
     {
         // create configuration first so the working directory is available for all adapters
         $configuration = new Configuration();

src/Configuration/Loader/Xml.php

@@ -92,6 +92,8 @@ public function __construct(string $file, Configuration\Bootstrapper $bootstrapp
         parent::__construct($file, $bootstrapper);
         $this->document = $this->loadXmlFile($file);
         $this->xpath    = new DOMXPath($this->document);
+
+        $this->validateConfigurationAgainstSchema();
     }
 
     /**
@@ -344,8 +346,9 @@ protected function setCleanup(Configuration\Backup $backup, DOMElement $node)
     /**
      * Extracts all option tags.
      *
-     * @param  DOMElement $node
+     * @param  \DOMElement $node
      * @return array
+     * @throws \phpbu\App\Exception
      */
     protected function getOptions(DOMElement $node)
     {
@@ -395,4 +398,27 @@ private function loadXmlFile($filename)
         }
         return $document;
     }
+
+    /**
+     * Validate xml configuration against phpbu.xsd schema
+     *
+     * @return void
+     */
+    private function validateConfigurationAgainstSchema() : void
+    {
+        $original    = \libxml_use_internal_errors(true);
+        $xsdFilename = __DIR__ . '/../../../phpbu.xsd';
+        if (\defined('__PHPBU_PHAR_ROOT__')) {
+            $xsdFilename =  __PHPBU_PHAR_ROOT__ . '/phpbu.xsd';
+        }
+        $this->document->schemaValidate($xsdFilename);
+        foreach (\libxml_get_errors() as $error) {
+            if (!isset($this->errors[$error->line])) {
+                $this->errors[$error->line] = [];
+            }
+            $this->errors[$error->line][] = \trim($error->message);
+        }
+        \libxml_clear_errors();
+        \libxml_use_internal_errors($original);
+    }
 }