Feature: support typehints in function signature

Author: paxal

rules.neon

@@ -9,4 +9,5 @@ rules:
 	- PHPStan\Rules\Deprecations\InheritanceOfDeprecatedClassRule
 	- PHPStan\Rules\Deprecations\InheritanceOfDeprecatedInterfaceRule
 	- PHPStan\Rules\Deprecations\InstantiationOfDeprecatedClassRule
+	- PHPStan\Rules\Deprecations\TypeHintDeprecatedInFunctionSignatureRule
 	- PHPStan\Rules\Deprecations\UsageOfDeprecatedTraitRule

src/Rules/Deprecations/TypeHintDeprecatedInFunctionSignatureRule.php

@@ -0,0 +1,106 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Deprecations;
+
+use PhpParser\Node;
+use PHPStan\Analyser\Scope;
+use PHPStan\Broker\Broker;
+
+class TypeHintDeprecatedInFunctionSignatureRule implements \PHPStan\Rules\Rule
+{
+
+	/** @var Broker */
+	private $broker;
+
+	public function __construct(Broker $broker)
+	{
+		$this->broker = $broker;
+	}
+
+	public function getNodeType(): string
+	{
+		return Node\FunctionLike::class;
+	}
+
+	/**
+	 * @param Node\FunctionLike $node
+	 * @param \PHPStan\Analyser\Scope $scope
+	 * @return string[] errors
+	 */
+	public function processNode(Node $node, Scope $scope): array
+	{
+		$errors = [];
+		foreach ($node->getParams() as $i => $param) {
+			$className = $this->getClassName($param->type, $scope);
+			if ($className === null) {
+				continue;
+			}
+
+			$errors[] = $this->checkClasses($className, 'argument #' . $i);
+		}
+
+		$className = $this->getClassName($node->getReturnType(), $scope);
+		if ($className !== null) {
+			$errors[] = $this->checkClasses($className, 'return type');
+		}
+
+		return array_filter($errors);
+	}
+
+	/**
+	 * @param null|Node\Name|Node\Identifier|Node\NullableType $type
+	 * @param Scope $scope
+	 * @return string|null
+	 */
+	private function getClassName($type, Scope $scope): ?string
+	{
+		if ($type instanceof Node\NullableType) {
+			return $this->getClassName($type->type, $scope);
+		}
+
+		if ($type instanceof Node\Name) {
+			return $scope->resolveName($type);
+		}
+
+		if ($type instanceof Node\Identifier) {
+			return null;
+		}
+
+		return null;
+	}
+
+
+	private function checkClasses(string $referencedClass, string $where): ?string
+	{
+		try {
+			$class = $this->broker->getClass($referencedClass);
+		} catch (\PHPStan\Broker\ClassNotFoundException $e) {
+			return null;
+		}
+
+		if ($class->isDeprecated()) {
+			$classDescription = null;
+			if (method_exists($class, 'getDeprecatedDescription')) {
+				$classDescription = $class->getDeprecatedDescription();
+			}
+
+			if ($classDescription === null) {
+				return sprintf(
+					'Usage of deprecated class %s in %s.',
+					$referencedClass,
+					$where
+				);
+			}
+
+			return sprintf(
+				"Usage of deprecated class %s in %s:\n%s",
+				$referencedClass,
+				$where,
+				$classDescription
+			);
+		}
+
+		return null;
+	}
+
+}

tests/Rules/Deprecations/TypeHintDeprecatedInFunctionSignatureRuleTest.php

@@ -0,0 +1,28 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Deprecations;
+
+class TypeHintDeprecatedInFunctionSignatureRuleTest extends \PHPStan\Testing\RuleTestCase
+{
+
+	protected function getRule(): \PHPStan\Rules\Rule
+	{
+		$broker = $this->createBroker();
+
+		return new TypeHintDeprecatedInFunctionSignatureRule($broker);
+	}
+
+	public function test(): void
+	{
+		require_once __DIR__ . '/data/typehint-deprecated-class-definition.php';
+		$this->analyse(
+			[__DIR__ . '/data/typehint-deprecated-class.php'],
+			[
+				['Usage of deprecated class TypeHintDeprecatedInFunctionSignature\DeprecatedProperty in argument #0.', 10],
+				['Usage of deprecated class TypeHintDeprecatedInFunctionSignature\DeprecatedProperty in argument #1.', 10],
+				['Usage of deprecated class TypeHintDeprecatedInFunctionSignature\DeprecatedProperty in return type.', 10],
+			]
+		);
+	}
+
+}

tests/Rules/Deprecations/data/typehint-deprecated-class-definition.php

@@ -0,0 +1,16 @@
+<?php
+
+namespace TypeHintDeprecatedInFunctionSignature;
+
+/**
+ * @deprecated
+ */
+class DeprecatedProperty
+{
+
+}
+
+class Property
+{
+
+}

tests/Rules/Deprecations/data/typehint-deprecated-class.php

@@ -0,0 +1,28 @@
+<?php
+
+namespace TypeHintDeprecatedInFunctionSignature;
+
+class Foo
+{
+
+    private $properties;
+
+    public function setProperties(
+        DeprecatedProperty $property,
+        ?DeprecatedProperty $property2,
+        $property3,
+        Property $property4,
+        string $property5
+    ): DeprecatedProperty {
+        $this->properties = [
+            $property,
+            $property2,
+            $property3,
+            $property4,
+            $property5,
+        ];
+
+        return $property;
+    }
+
+}