Report deprecated casts in PHP 8.5

Author: ondrejmirtes

Makefile

@@ -116,6 +116,7 @@ lint:
 		--exclude tests/PHPStan/Rules/Functions/data/closure-typehints-nodiscard.php \
 		--exclude tests/PHPStan/Rules/Functions/data/typehints-nodiscard.php \
 		--exclude tests/PHPStan/Rules/Methods/data/typehints-nodiscard.php \
+		--exclude tests/PHPStan/Rules/Cast/data/deprecated-cast.php \
 		src tests
 
 install-paratest:

src/Php/PhpVersion.php

@@ -439,4 +439,9 @@ public function supportsNoDiscardAttribute(): bool
 		return $this->versionId >= 80500;
 	}
 
+	public function deprecatesNonStandardCasts(): bool
+	{
+		return $this->versionId >= 80500;
+	}
+
 }

src/Rules/Cast/DeprecatedCastRule.php

@@ -0,0 +1,90 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Cast;
+
+use PhpParser\Node;
+use PhpParser\Node\Expr\Cast;
+use PHPStan\Analyser\Scope;
+use PHPStan\DependencyInjection\RegisteredRule;
+use PHPStan\Php\PhpVersion;
+use PHPStan\Rules\Rule;
+use PHPStan\Rules\RuleErrorBuilder;
+
+/**
+ * @implements Rule<Cast>
+ */
+#[RegisteredRule(level: 0)]
+final class DeprecatedCastRule implements Rule
+{
+
+	public function __construct(private PhpVersion $phpVersion)
+	{
+	}
+
+	public function getNodeType(): string
+	{
+		return Cast::class;
+	}
+
+	public function processNode(Node $node, Scope $scope): array
+	{
+		if (!$this->phpVersion->deprecatesNonStandardCasts()) {
+			return [];
+		}
+
+		if ($node instanceof Cast\Int_) {
+			$kind = $node->getAttribute('kind', Cast\Int_::KIND_INT);
+			if ($kind === Cast\Int_::KIND_INTEGER) {
+				return [
+					RuleErrorBuilder::message('Non-standard (integer) cast is deprecated in PHP 8.5. Use (int) instead.')
+						->identifier('cast.deprecated')
+						->build(),
+				];
+			}
+
+			return [];
+		}
+
+		if ($node instanceof Cast\Bool_) {
+			$kind = $node->getAttribute('kind', Cast\Bool_::KIND_BOOL);
+			if ($kind === Cast\Bool_::KIND_BOOLEAN) {
+				return [
+					RuleErrorBuilder::message('Non-standard (boolean) cast is deprecated in PHP 8.5. Use (bool) instead.')
+						->identifier('cast.deprecated')
+						->build(),
+				];
+			}
+
+			return [];
+		}
+
+		if ($node instanceof Cast\Double) {
+			$kind = $node->getAttribute('kind', Cast\Double::KIND_FLOAT);
+			if ($kind === Cast\Double::KIND_DOUBLE) {
+				return [
+					RuleErrorBuilder::message('Non-standard (double) cast is deprecated in PHP 8.5. Use (float) instead.')
+						->identifier('cast.deprecated')
+						->build(),
+				];
+			}
+
+			return [];
+		}
+
+		if ($node instanceof Cast\String_) {
+			$kind = $node->getAttribute('kind', Cast\String_::KIND_STRING);
+			if ($kind === Cast\String_::KIND_BINARY) {
+				return [
+					RuleErrorBuilder::message('Non-standard (binary) cast is deprecated in PHP 8.5. Use (string) instead.')
+						->identifier('cast.deprecated')
+						->build(),
+				];
+			}
+
+			return [];
+		}
+
+		return [];
+	}
+
+}

tests/PHPStan/Rules/Cast/DeprecatedCastRuleTest.php

@@ -0,0 +1,48 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Cast;
+
+use PHPStan\Php\PhpVersion;
+use PHPStan\Rules\Rule;
+use PHPStan\Testing\RuleTestCase;
+use const PHP_VERSION_ID;
+
+/**
+ * @extends RuleTestCase<DeprecatedCastRule>
+ */
+class DeprecatedCastRuleTest extends RuleTestCase
+{
+
+	protected function getRule(): Rule
+	{
+		return new DeprecatedCastRule(new PhpVersion(PHP_VERSION_ID));
+	}
+
+	public function testRule(): void
+	{
+		$errors = [];
+		if (PHP_VERSION_ID >= 80500) {
+			$errors = [
+				[
+					'Non-standard (integer) cast is deprecated in PHP 8.5. Use (int) instead.',
+					7,
+				],
+				[
+					'Non-standard (boolean) cast is deprecated in PHP 8.5. Use (bool) instead.',
+					10,
+				],
+				[
+					'Non-standard (double) cast is deprecated in PHP 8.5. Use (float) instead.',
+					13,
+				],
+				[
+					'Non-standard (binary) cast is deprecated in PHP 8.5. Use (string) instead.',
+					16,
+				],
+			];
+		}
+
+		$this->analyse([__DIR__ . '/data/deprecated-cast.php'], $errors);
+	}
+
+}

tests/PHPStan/Rules/Cast/data/deprecated-cast.php

@@ -0,0 +1,17 @@
+<?php
+
+namespace DeprecatedCast;
+
+function ($m): void {
+	(int) $m;
+	(integer) $m;
+
+	(bool) $m;
+	(boolean) $m;
+
+	(float) $m;
+	(double) $m;
+
+	(string) $m;
+	(binary) $m;
+};