Include and document MEQP2.Templates.ThisInTemplate

Extdn/ruleset.xml

@@ -3,6 +3,9 @@
     <description>Magento 2 Additional Rules by ExtDN</description>
     <rule ref="PSR1"/>
     <rule ref="PSR2"/>
+    <rule ref="MEQP2.Templates.ThisInTemplate">
+        <exclude-pattern>*.php</exclude-pattern>
+    </rule>
     <rule ref="Extdn.Blocks.SetTemplateInBlock"/>
     <rule ref="Extdn.Classes.StrictTypes"/>
     <rule ref="Extdn.Templates.TemplateObjectManager"/>

MEQP2/Sniffs/Templates/ThisInTemplateSniff.md

@@ -0,0 +1,13 @@
+# Rule: Do not use `$this` in templates
+## Background
+In PHTML templates, the current block is available as `$this` and `$block`. The alternative with `$this` has been deprecated and should not be used anymore.
+
+## Reasoning
+`$this` in templates is a legacy from Magento 1. It still works, however this can change any time, should templates and blocks be further decoupled. That's why for new code you should always use `$block` and restrict it to public methods.
+
+## How it works
+Any occurence of `$this` in PHTML files (via file pattern in ruleset.xml) raises a warning. 
+
+## How to fix
+
+Replace `$this` with `$block`. If you use private or protected methods, make them public.

README.md

@@ -38,7 +38,7 @@ As an example, you can use the `SetTemplateInBlockSniff` within the folder `Extd
 
 To run the sniff unit tests from a main repository, where the rules are installed via composer, first configure phpcs to find the rules:
 
-    vendor/bin/phpcs --config-set installed_paths vendor/extdn/phpcs/Extdn
+    vendor/bin/phpcs --config-set installed_paths vendor/extdn/phpcs/Extdn,vendor/magento/marketplace-eqp/MEQP2
 
 Then tests can be run like this:
 

composer.json

@@ -12,7 +12,8 @@
     ],
     "require": {
         "php": ">=7.1.0",
-        "squizlabs/php_codesniffer": "3.*"
+        "squizlabs/php_codesniffer": "3.*",
+        "magento/marketplace-eqp": "dev-master"
     },
     "autoload": {
         "psr-4": {
@@ -31,5 +32,11 @@
         "post-install-cmd": "\"vendor/bin/phpcs\" --config-set installed_paths ../../..",
         "post-update-cmd": "\"vendor/bin/phpcs\" --config-set installed_paths ../../..",
         "test": "vendor/bin/phpunit"
+    },
+    "repositories": {
+        "meqp": {
+            "type": "vcs",
+            "url": "git@github.com:magento/marketplace-eqp.git"
+        }
     }
 }