Raise PHPStan to level 4

.gitignore

@@ -4,3 +4,4 @@ composer.lock
 .php_cs.cache
 .php-cs-fixer.cache
 .phpunit.result.cache
+phpstan.neon

.php-cs-fixer.php

@@ -22,6 +22,7 @@
         'ordered_imports' => true,
         'php_unit_strict' => false,
         'phpdoc_order' => true,
+        'phpdoc_to_param_type' => true,
         // 'psr4' => true,
         'strict_comparison' => true,
         'strict_param' => true,

composer.json

@@ -44,7 +44,10 @@
         "psr-4": { "Readability\\": "src/" }
     },
     "autoload-dev": {
-        "psr-4": { "Tests\\Readability\\": "tests/" }
+        "psr-4": {
+            "Tests\\Readability\\": "tests/",
+            "Readability\\Maintenance\\": "maintenance/"
+        }
     },
     "scripts": {
         "fix": "php-cs-fixer fix --verbose --diff",

maintenance/PHPStan/DOMDocumentGetElementDynamicReturnTypeExtension.php

@@ -0,0 +1,38 @@
+<?php
+
+namespace Readability\Maintenance\PHPStan;
+
+use Readability\JSLikeHTMLElement;
+use PHPStan\Type\Generic\GenericObjectType;
+use PhpParser\Node\Expr\MethodCall;
+use PHPStan\Analyser\Scope;
+use PHPStan\Reflection\MethodReflection;
+use PHPStan\Type\DynamicMethodReturnTypeExtension;
+use PHPStan\Type\Type;
+use PHPStan\Type\ArrayType;
+use PHPStan\Type\ObjectType;
+
+class DOMDocumentGetElementDynamicReturnTypeExtension implements DynamicMethodReturnTypeExtension
+{
+	public function getClass(): string
+	{
+		return \DOMDocument::class;
+	}
+
+	public function isMethodSupported(MethodReflection $methodReflection): bool
+	{
+		return in_array($methodReflection->getName(),
+			[
+				'createElement',
+			], true);
+	}
+
+	public function getTypeFromMethodCall(
+		MethodReflection $methodReflection,
+		MethodCall $methodCall,
+		Scope $scope
+	): ?Type
+	{
+		return new ObjectType(JSLikeHTMLElement::class);
+	}
+}

maintenance/PHPStan/DOMDocumentGetElementsDynamicReturnTypeExtension.php

@@ -0,0 +1,39 @@
+<?php
+
+namespace Readability\Maintenance\PHPStan;
+
+use Readability\JSLikeHTMLElement;
+use PHPStan\Type\Generic\GenericObjectType;
+use PhpParser\Node\Expr\MethodCall;
+use PHPStan\Analyser\Scope;
+use PHPStan\Reflection\MethodReflection;
+use PHPStan\Type\DynamicMethodReturnTypeExtension;
+use PHPStan\Type\Type;
+use PHPStan\Type\ArrayType;
+use PHPStan\Type\ObjectType;
+
+class DOMDocumentGetElementsDynamicReturnTypeExtension implements DynamicMethodReturnTypeExtension
+{
+	public function getClass(): string
+	{
+		return \DOMDocument::class;
+	}
+
+	public function isMethodSupported(MethodReflection $methodReflection): bool
+	{
+		return in_array($methodReflection->getName(),
+			[
+				'getElementsByTagName',
+			], true);
+	}
+
+	public function getTypeFromMethodCall(
+		MethodReflection $methodReflection,
+		MethodCall $methodCall,
+		Scope $scope
+	): ?Type
+	{
+		$elementType = new ObjectType(JSLikeHTMLElement::class);
+		return new GenericObjectType(\DOMNodeList::class, [$elementType]);
+	}
+}

maintenance/PHPStan/DOMElementGetElementsDynamicReturnTypeExtension.php

@@ -0,0 +1,39 @@
+<?php
+
+namespace Readability\Maintenance\PHPStan;
+
+use Readability\JSLikeHTMLElement;
+use PHPStan\Type\Generic\GenericObjectType;
+use PhpParser\Node\Expr\MethodCall;
+use PHPStan\Analyser\Scope;
+use PHPStan\Reflection\MethodReflection;
+use PHPStan\Type\DynamicMethodReturnTypeExtension;
+use PHPStan\Type\Type;
+use PHPStan\Type\ArrayType;
+use PHPStan\Type\ObjectType;
+
+class DOMElementGetElementsDynamicReturnTypeExtension implements DynamicMethodReturnTypeExtension
+{
+	public function getClass(): string
+	{
+		return \DOMElement::class;
+	}
+
+	public function isMethodSupported(MethodReflection $methodReflection): bool
+	{
+		return in_array($methodReflection->getName(),
+			[
+				'getElementsByTagName',
+			], true);
+	}
+
+	public function getTypeFromMethodCall(
+		MethodReflection $methodReflection,
+		MethodCall $methodCall,
+		Scope $scope
+	): ?Type
+	{
+		$elementType = new ObjectType(JSLikeHTMLElement::class);
+		return new GenericObjectType(\DOMNodeList::class, [$elementType]);
+	}
+}

phpstan.dist.neon

@@ -0,0 +1,30 @@
+parameters:
+    level: 4
+    paths:
+        - src
+        - tests
+
+    # https://github.com/phpstan/phpstan/issues/694#issuecomment-350724288
+    bootstrapFiles:
+        - vendor/bin/.phpunit/phpunit/vendor/autoload.php
+
+includes:
+    - vendor/phpstan/phpstan-phpunit/extension.neon
+    - vendor/phpstan/phpstan-phpunit/rules.neon
+    - phar://phpstan.phar/conf/bleedingEdge.neon
+
+services:
+    -
+        class: Readability\Maintenance\PHPStan\DOMDocumentGetElementDynamicReturnTypeExtension
+        tags:
+            - phpstan.broker.dynamicMethodReturnTypeExtension
+
+    -
+        class: Readability\Maintenance\PHPStan\DOMDocumentGetElementsDynamicReturnTypeExtension
+        tags:
+            - phpstan.broker.dynamicMethodReturnTypeExtension
+
+    -
+        class: Readability\Maintenance\PHPStan\DOMElementGetElementsDynamicReturnTypeExtension
+        tags:
+            - phpstan.broker.dynamicMethodReturnTypeExtension