[New Rule] Proxies and interceptors MUST never be explicitly requested in constructors

[lenaorobei]

Rule

Proxies and interceptors MUST never be explicitly requested in constructors.

Source - Magento Technical Guidelines

Description

Proxies are used for lazy-loading. Details on DevDocs.

Proxies should be configured via di.xml file.

<type name="FastLoading">
    <arguments>
        <argument name="slowLoading" xsi:type="object">SlowLoading\Proxy</argument>
    </arguments>
</type>

Plugins (interceptors) modify the behavior of public class functions by intercepting a function call and running code before, after, or around that function call. Details on DevDocs.

Plugins should be declared via di.xml file.

<config>
    <type name="{ObservedType}">
      <plugin name="{pluginName}" type="{PluginClassName}" sortOrder="1" disabled="false" />
    </type>
</config>

Implementation

Subscribe to the T_CLASS token and analyse __constructor arguments.

<severity>8</severity>
<type>warning</type>

[maderlock]

After discussion in pull-request, the scope of this has changed slightly:

1. This will output errors instead of warnings
2. Rather than detect plugins, the interceptors themselves will be detected