Rule to check for use of deprecated constants

Author: cs278

src/Rules/Deprecations/FetchingDeprecatedConstRule.php

@@ -0,0 +1,64 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Deprecations;
+
+use PhpParser\Node;
+use PhpParser\Node\Expr\ConstFetch;
+use PHPStan\Analyser\Scope;
+use PHPStan\Reflection\GlobalConstantReflection;
+use PHPStan\Reflection\ReflectionProvider;
+
+/**
+ * @implements \PHPStan\Rules\Rule<ConstFetch>
+ */
+class FetchingDeprecatedConstRule implements \PHPStan\Rules\Rule
+{
+
+	/** @var ReflectionProvider */
+	private $reflectionProvider;
+
+	/** @var array<string,string> */
+	private $deprecatedConstants = [
+		'FILTER_FLAG_SCHEME_REQUIRED' => 'Use of constant %s is deprecated since PHP 7.3.',
+		'FILTER_FLAG_HOST_REQUIRED' => 'Use of constant %s is deprecated since PHP 7.3.',
+	];
+
+	public function __construct(ReflectionProvider $reflectionProvider)
+	{
+		$this->reflectionProvider = $reflectionProvider;
+	}
+
+	public function getNodeType(): string
+	{
+		return ConstFetch::class;
+	}
+
+	public function processNode(Node $node, Scope $scope): array
+	{
+		if (DeprecatedScopeHelper::isScopeDeprecated($scope)) {
+			return [];
+		}
+
+		if (!$this->reflectionProvider->hasConstant($node->name, $scope)) {
+			return [];
+		}
+
+		$constantReflection = $this->reflectionProvider->getConstant($node->name, $scope);
+
+		if ($this->isDeprecated($constantReflection)) {
+			return [sprintf(
+				$this->deprecatedConstants[$constantReflection->getName()] ?? 'Use of constant %s is deprecated.',
+				$constantReflection->getName()
+			)];
+		}
+
+		return [];
+	}
+
+	private function isDeprecated(GlobalConstantReflection $constantReflection): bool
+	{
+		return $constantReflection->isDeprecated()->yes()
+			|| isset($this->deprecatedConstants[$constantReflection->getName()]);
+	}
+
+}

tests/Rules/Deprecations/FetchingDeprecatedConstRuleTest.php

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+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Deprecations;
+
+/**
+ * @extends \PHPStan\Testing\RuleTestCase<FetchingDeprecatedConstRule>
+ */
+class FetchingDeprecatedConstRuleTest extends \PHPStan\Testing\RuleTestCase
+{
+
+	protected function getRule(): \PHPStan\Rules\Rule
+	{
+		return new FetchingDeprecatedConstRule($this->createReflectionProvider());
+	}
+
+	public function testFetchingDeprecatedConst(): void
+	{
+		if (!defined('FILTER_FLAG_SCHEME_REQUIRED') || !defined('FILTER_FLAG_HOST_REQUIRED')) {
+			$this->markTestSkipped('Required constants are not available, PHP≥8?');
+		}
+
+		require_once __DIR__ . '/data/fetching-deprecated-const-definition.php';
+		$this->analyse(
+			[__DIR__ . '/data/fetching-deprecated-const.php'],
+			[
+				[
+					'Use of constant FILTER_FLAG_SCHEME_REQUIRED is deprecated since PHP 7.3.',
+					5,
+				],
+				[
+					'Use of constant FILTER_FLAG_HOST_REQUIRED is deprecated since PHP 7.3.',
+					6,
+				],
+				[
+					'Use of constant FILTER_FLAG_SCHEME_REQUIRED is deprecated since PHP 7.3.',
+					7,
+				],
+				[
+					'Use of constant FILTER_FLAG_HOST_REQUIRED is deprecated since PHP 7.3.',
+					8,
+				],
+				[
+					'Use of constant FILTER_FLAG_SCHEME_REQUIRED is deprecated since PHP 7.3.',
+					37,
+				],
+				[
+					'Use of constant FILTER_FLAG_HOST_REQUIRED is deprecated since PHP 7.3.',
+					38,
+				],
+			]
+		);
+	}
+
+}

tests/Rules/Deprecations/data/fetching-deprecated-const-definition.php

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+<?php
+
+namespace FetchingDeprecatedConst\Redefined {
+
+	const FILTER_FLAG_SCHEME_REQUIRED = 'foo2';
+	const FILTER_FLAG_HOST_REQUIRED = 'bar2';
+
+}

tests/Rules/Deprecations/data/fetching-deprecated-const.php

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+<?php
+
+namespace FetchingDeprecatedConst {
+
+	\FILTER_FLAG_SCHEME_REQUIRED;
+	\FILTER_FLAG_HOST_REQUIRED;
+	FILTER_FLAG_SCHEME_REQUIRED;
+	FILTER_FLAG_HOST_REQUIRED;
+
+	/**
+	 * @deprecated
+	 */
+	function deprecated_scope()
+	{
+		\FILTER_FLAG_SCHEME_REQUIRED;
+		\FILTER_FLAG_HOST_REQUIRED;
+	}
+
+	/**
+	 * @deprecated nothing to see
+	 */
+	class deprecated_scope2
+	{
+
+		public function test()
+		{
+			\FILTER_FLAG_SCHEME_REQUIRED;
+			\FILTER_FLAG_HOST_REQUIRED;
+		}
+
+	}
+
+}
+
+namespace FetchingDeprecatedConst\Redefined {
+
+	\FILTER_FLAG_SCHEME_REQUIRED;
+	\FILTER_FLAG_HOST_REQUIRED;
+	FILTER_FLAG_SCHEME_REQUIRED; // ok
+	FILTER_FLAG_HOST_REQUIRED; // ok
+
+}