Add additional coding standard rules

composer.json

@@ -17,7 +17,8 @@
   "require-dev": {
     "phpunit/phpunit": "^9",
     "phpstan/phpstan": "^1",
-    "squizlabs/php_codesniffer": "^3.8"
+    "squizlabs/php_codesniffer": "^3.8",
+    "slevomat/coding-standard": "~8.0"
   },
   "autoload": {
     "psr-4": {
@@ -29,5 +30,10 @@
       "Intervention\\Gif\\Tests\\": "tests"
     }
   },
-  "minimum-stability": "stable"
+  "minimum-stability": "stable",
+  "config": {
+    "allow-plugins": {
+      "dealerdirect/phpcodesniffer-composer-installer": true
+    }
+  }
 }

phpcs.xml

@@ -1,11 +1,68 @@
 <?xml version="1.0"?>
-<ruleset name="Intervention/gif">
-
-  <rule ref="PSR12"/>
-
+<ruleset name="Intervention">
+  <file>src/</file>
+  <file>tests/</file>
   <arg name="colors"/>
   <arg value="p"/>
 
-  <file>src/</file>
-  <file>tests/</file>
+  <rule ref="PSR12"/>
+  <rule ref="Generic.Arrays.ArrayIndent"/>
+  <rule ref="Generic.ControlStructures.InlineControlStructure"/>
+  <rule ref="Generic.Formatting.SpaceAfterCast"/>
+  <rule ref="Generic.Formatting.SpaceAfterNot">
+    <properties>
+      <property name="spacing" value="0" />
+    </properties>
+  </rule>
+  <rule ref="Generic.Metrics.NestingLevel"/>
+  <rule ref="SlevomatCodingStandard.Arrays.SingleLineArrayWhitespace"/>
+  <rule ref="SlevomatCodingStandard.Arrays.DisallowImplicitArrayCreation"/>
+  <rule ref="SlevomatCodingStandard.Classes.ClassConstantVisibility"/>
+  <rule ref="SlevomatCodingStandard.Classes.ClassMemberSpacing"/>
+  <rule ref="SlevomatCodingStandard.Classes.ConstantSpacing"/>
+  <rule ref="SlevomatCodingStandard.Classes.MethodSpacing"/>
+  <rule ref="SlevomatCodingStandard.Classes.ModernClassNameReference"/>
+  <rule ref="SlevomatCodingStandard.Classes.ParentCallSpacing"/>
+  <rule ref="SlevomatCodingStandard.Classes.PropertyDeclaration"/>
+  <rule ref="SlevomatCodingStandard.Classes.RequireSelfReference"/>
+  <rule ref="SlevomatCodingStandard.Classes.TraitUseDeclaration"/>
+  <rule ref="SlevomatCodingStandard.Files.TypeNameMatchesFileName">
+    <properties>
+      <property name="rootNamespaces" type="array">
+        <element key="src" value="Intervention\Gif"/>
+        <element key="tests" value="Intervention\Gif\Tests"/>
+      </property>
+    </properties>
+  </rule>
+  <rule ref="SlevomatCodingStandard.Namespaces.DisallowGroupUse"/>
+  <rule ref="SlevomatCodingStandard.Namespaces.MultipleUsesPerLine"/>
+  <rule ref="SlevomatCodingStandard.Namespaces.UnusedUses">
+    <properties>
+      <property name="searchAnnotations" value="true" />
+    </properties>
+  </rule>
+  <rule ref="SlevomatCodingStandard.Namespaces.UseDoesNotStartWithBackslash"/>
+  <rule ref="SlevomatCodingStandard.Namespaces.UseFromSameNamespace"/>
+  <rule ref="SlevomatCodingStandard.Namespaces.UseSpacing"/>
+  <rule ref="SlevomatCodingStandard.Namespaces.UselessAlias"/>
+  <rule ref="SlevomatCodingStandard.Strings.DisallowVariableParsing"/>
+  <rule ref="SlevomatCodingStandard.TypeHints.DeclareStrictTypes">
+    <properties>
+      <property name="spacesCountAroundEqualsSign" value="0" />
+    </properties>
+  </rule>
+  <rule ref="SlevomatCodingStandard.TypeHints.LongTypeHints"/>
+  <rule ref="SlevomatCodingStandard.TypeHints.NullableTypeForNullDefaultValue"/>
+  <rule ref="SlevomatCodingStandard.TypeHints.ParameterTypeHintSpacing"/>
+  <rule ref="SlevomatCodingStandard.TypeHints.ReturnTypeHintSpacing"/>
+  <rule ref="SlevomatCodingStandard.TypeHints.UnionTypeHintFormat">
+    <properties>
+      <property name="withSpaces" value="no" />
+      <property name="nullPosition" value="first" />
+    </properties>
+  </rule>
+  <rule ref="SlevomatCodingStandard.PHP.UselessSemicolon"/>
+  <rule ref="SlevomatCodingStandard.Whitespaces.DuplicateSpaces"/>
+  <rule ref="SlevomatCodingStandard.Variables.UnusedVariable"/>
+  <rule ref="SlevomatCodingStandard.Variables.UselessVariable"/>
 </ruleset>