Reintroduce support for Symfony 3 (#12)

Author: martin-georgiev

src/DependencyInjection/Configuration.php

@@ -12,8 +12,13 @@ class Configuration implements ConfigurationInterface
 {
     public function getConfigTreeBuilder(): TreeBuilder
     {
-        $treeBuilder = new TreeBuilder('alpha_visitor_tracking');
-        $rootNode = $treeBuilder->getRootNode();
+        if ($this->isBeforeSymfony4()) {
+            $treeBuilder = new TreeBuilder();
+            $rootNode = $treeBuilder->root('alpha_visitor_tracking');
+        } else {
+            $treeBuilder = new TreeBuilder('alpha_visitor_tracking');
+            $rootNode = $treeBuilder->getRootNode();
+        }
         \assert($rootNode instanceof ArrayNodeDefinition);
 
         $rootNode->append($this->createSubscriberNode());
@@ -23,8 +28,13 @@ public function getConfigTreeBuilder(): TreeBuilder
 
     private function createSubscriberNode(): ArrayNodeDefinition
     {
-        $treeBuilder = new TreeBuilder('session_subscriber');
-        $rootNode = $treeBuilder->getRootNode();
+        if ($this->isBeforeSymfony4()) {
+            $treeBuilder = new TreeBuilder();
+            $rootNode = $treeBuilder->root('session_subscriber');
+        } else {
+            $treeBuilder = new TreeBuilder('session_subscriber');
+            $rootNode = $treeBuilder->getRootNode();
+        }
         \assert($rootNode instanceof ArrayNodeDefinition);
 
         $rootNode->addDefaultsIfNotSet();
@@ -36,4 +46,9 @@ private function createSubscriberNode(): ArrayNodeDefinition
 
         return $rootNode;
     }
+
+    private function isBeforeSymfony4(): bool
+    {
+        return !\method_exists(TreeBuilder::class, 'getRootNode');
+    }
 }

tools/phpstan/phpstan.neon

@@ -5,6 +5,9 @@ parameters:
 	inferPrivatePropertyTypeFromConstructor: true
 	checkGenericClassInNonGenericObjectType: false
 	checkMissingIterableValueType: false
+	reportUnmatchedIgnoredErrors: false
+	ignoreErrors:
+		- "#Call to function method_exists() with 'Symfony\\\\Component…' and 'getRootNode' will always evaluate to false.#"
 
 services:
     -