Added PHPStan on level 0 for lib directory

.circleci/config.yml

@@ -42,6 +42,26 @@ jobs:
           root: /home/circleci/mailpoet
           paths:
             - .
+  static_analysis:
+    working_directory: /home/circleci/mailpoet
+    docker:
+    - image: mailpoet/wordpress:7.1_20181009.1
+    - image: circleci/mysql:5.7
+    environment:
+      TZ: /usr/share/zoneinfo/Etc/UTC
+    steps:
+    - attach_workspace:
+        at: /home/circleci/mailpoet
+    - run:
+        name: "Set up environment"
+        command: |
+          ./composer.phar install --no-dev --no-scripts
+          source ./.circleci/setup.bash && setup php7
+          wget https://github.com/phpstan/phpstan/releases/download/0.10.5/phpstan.phar
+    - run:
+        name: "Static analysis"
+        command: |
+          WP_ROOT="/home/circleci/mailpoet/wordpress" php -d memory_limit=2G phpstan.phar analyse -c tasks/phpstan/phpstan.neon -l 0 lib/
   php5_unit:
     working_directory: /home/circleci/mailpoet
     docker:
@@ -257,6 +277,9 @@ workflows:
   build_and_test:
     jobs:
       - build_and_code_qa
+      - static_analysis:
+          requires:
+            - build_and_code_qa
       - php5_unit:
           requires:
             - build_and_code_qa

tasks/phpstan/bootstrap.php

@@ -0,0 +1,6 @@
+<?php
+
+define('ABSPATH', getenv('WP_ROOT') . '/');
+
+require_once ABSPATH . 'wp-load.php';
+require_once ABSPATH . 'wp-admin/includes/admin.php';

tasks/phpstan/phpstan.neon

@@ -0,0 +1,11 @@
+parameters:
+	tmpDir: temp/phpstan
+	bootstrap: tasks/phpstan/bootstrap.php
+	ignoreErrors:
+		- '#Access to an undefined property#' # current code suffers from this, it should be fixed & this line removed
+		- '#Static call to instance method MailPoet\\Models\\Model::#'
+		- '#Access to an undefined static property MailPoet\\Models\\Model::#'
+		- '#Function members_register_.+ not found#'
+	excludes_analyse:
+		- lib/Dependencies
+		- lib/DI/CachedContainer.php