UselessCastRule on native types is auto-fixable

Makefile

@@ -7,7 +7,7 @@ tests:
 
 .PHONY: lint
 lint:
-	php vendor/bin/parallel-lint --colors \
+	php vendor/bin/parallel-lint --colors -e php,php3,php4,php5,phtml,phpt,fixed \
 		src tests
 
 .PHONY: cs-install

src/Rules/Cast/UselessCastRule.php

@@ -55,28 +55,39 @@ public function processNode(Node $node, Scope $scope): array
 			$expressionType = $scope->getNativeType($node->expr);
 		}
 		if ($castType->isSuperTypeOf($expressionType)->yes()) {
-			$addTip = function (RuleErrorBuilder $ruleErrorBuilder) use ($scope, $node, $castType): RuleErrorBuilder {
-				if (!$this->treatPhpDocTypesAsCertain) {
-					return $ruleErrorBuilder;
-				}
+			$ruleErrorBuilder = RuleErrorBuilder::message(sprintf(
+				'Casting to %s something that\'s already %s.',
+				$castType->describe(VerbosityLevel::typeOnly()),
+				$expressionType->describe(VerbosityLevel::typeOnly()),
+			))->identifier('cast.useless');
 
-				if (!$this->treatPhpDocTypesAsCertainTip) {
-					return $ruleErrorBuilder;
-				}
+			$nativeType = $scope->getNativeType($node->expr);
+			if ($castType->isSuperTypeOf($nativeType)->yes()) {
+				$ruleErrorBuilder->fixNode($node, static function (Cast $node) use ($nativeType): Node {
+					if ($node instanceof Cast\Bool_) {
+						if (!$nativeType->isBoolean()->yes()) {
+							return $node;
+						}
+					} elseif ($node instanceof Cast\Int_) {
+						if (
+							$node->expr instanceof Node\Expr\UnaryMinus
+							|| !$nativeType->isInteger()->yes()
+						) {
+							return $node;
+						}
+					} else {
+						// skip all other casts
+						return $node;
+					}
 
-				$expressionTypeWithoutPhpDoc = $scope->getNativeType($node->expr);
-				if ($castType->isSuperTypeOf($expressionTypeWithoutPhpDoc)->yes()) {
-					return $ruleErrorBuilder;
-				}
+					return $node->expr;
+				});
+			} elseif ($this->treatPhpDocTypesAsCertain && $this->treatPhpDocTypesAsCertainTip) {
+				$ruleErrorBuilder->treatPhpDocTypesAsCertainTip();
+			}
 
-				return $ruleErrorBuilder->treatPhpDocTypesAsCertainTip();
-			};
 			return [
-				$addTip(RuleErrorBuilder::message(sprintf(
-					'Casting to %s something that\'s already %s.',
-					$castType->describe(VerbosityLevel::typeOnly()),
-					$expressionType->describe(VerbosityLevel::typeOnly()),
-				)))->identifier('cast.useless')->build(),
+				$ruleErrorBuilder->build(),
 			];
 		}
 

tests/Rules/Cast/UselessCastRuleTest.php

@@ -13,11 +13,13 @@ class UselessCastRuleTest extends RuleTestCase
 
 	private bool $treatPhpDocTypesAsCertain;
 
+	private bool $treatPhpDocTypesAsCertainTip = true;
+
 	protected function getRule(): Rule
 	{
 		return new UselessCastRule(
 			$this->treatPhpDocTypesAsCertain,
-			true,
+			$this->treatPhpDocTypesAsCertainTip,
 		);
 	}
 
@@ -95,4 +97,31 @@ public function testBug14565(): void
 		$this->analyse([__DIR__ . '/data/bug-14565.php'], []);
 	}
 
+	public function testVoidCastIsNotFixed(): void
+	{
+		$this->treatPhpDocTypesAsCertain = true;
+		$this->fix(__DIR__ . '/data/bug-14565.php', __DIR__ . '/data/bug-14565.php');
+	}
+
+	/**
+	 * @return iterable<array{bool, bool}>
+	 */
+	public function dataFix(): iterable
+	{
+		yield [true, true];
+		yield [true, false];
+		yield [false, true];
+		yield [false, false];
+	}
+
+	/**
+	 * @dataProvider dataFix
+	 */
+	public function testFix(bool $treatPhpDocTypesAsCertain, bool $treatPhpDocTypesAsCertainTip): void
+	{
+		$this->treatPhpDocTypesAsCertain = $treatPhpDocTypesAsCertain;
+		$this->treatPhpDocTypesAsCertainTip = $treatPhpDocTypesAsCertainTip;
+		$this->fix(__DIR__ . '/data/useless-cast-fixable.php', __DIR__ . '/data/useless-cast-fixable.php.fixed');
+	}
+
 }

tests/Rules/Cast/data/useless-cast-fixable.php

@@ -0,0 +1,115 @@
+<?php declare(strict_types = 1);
+
+namespace UselessCastFixable;
+
+use stdClass;
+
+/**
+ * @param bool $phpDocBoolean
+ * @param int $phpDocInteger
+ * @param float $phpDocFloat
+ * @param string $phpDocString
+ * @param array<int> $phpDocArray
+ * @param stdClass $phpDocObject
+ * @param non-empty-string $string
+ */
+function casts(
+	bool $boolean,
+	int $integer,
+	float $float,
+	string $string,
+	array $array,
+	stdClass $object,
+	?int $nullableInteger,
+	$phpDocBoolean,
+	$phpDocInteger,
+	$phpDocFloat,
+	$phpDocString,
+	$phpDocArray,
+	$phpDocObject,
+	$mixed
+): void
+{
+	(bool) $boolean;
+	(int) $integer;
+	(float) $float;
+	(string) $string;
+	(array) $array;
+	(object) $object;
+
+	(bool) $phpDocBoolean;
+	(int) $phpDocInteger;
+	(float) $phpDocFloat;
+	(string) $phpDocString;
+	(array) $phpDocArray;
+	(object) $phpDocObject;
+
+	(string) $integer;
+	(int) $nullableInteger;
+	(int) $mixed;
+
+	if ($nullableInteger !== null) {
+		(int) $nullableInteger;
+	}
+	if (is_int($mixed)) {
+		(int) $mixed;
+	}
+
+	(int) 42;
+	(bool) true;
+	(string) 'value';
+	(array) [1, 2];
+	(object) new stdClass();
+	(int) ($integer + 1) * 2;
+	2 - (int) ($integer + 1);
+	(bool) ($boolean || true) && false;
+	(int) ($integer = 1) + 2;
+	(int) ($integer + 1) ** 2;
+	(int) ($boolean ? $integer : 0);
+	(int) ++$integer;
+	(int) strlen($string);
+	$b = $integer-(int)-$integer;
+}
+
+class Foo
+{
+	public static function bug(string $key): void
+	{
+		$a = [$key => 1];
+
+		foreach ($a as $k => $v) {
+			$l = strlen((string)$k); // type cast is needed for auto-coerced non-decimal-int-string
+		}
+	}
+}
+
+// https://3v4l.org/krTct#v
+function doFoo() {
+	$array = [0, 1];
+	foreach ((array) $array as &$v) {
+		$v=2;
+	}
+	var_dump($array);
+}
+function doBar() {
+	$array = [0, 1];
+	foreach ($array as &$v) {
+		$v=2;
+	}
+	var_dump($array);
+}
+doFoo();
+doBar();
+
+class X {
+	public int $i;
+	public string $s;
+}
+
+function doBaz(X $x) {
+	echo (int) $x->i;
+	echo (int) $x->s;
+
+	echo (string) $x->i;
+	echo (string) $x->s;
+}

tests/Rules/Cast/data/useless-cast-fixable.php.fixed

@@ -0,0 +1,115 @@
+<?php declare(strict_types = 1);
+
+namespace UselessCastFixable;
+
+use stdClass;
+
+/**
+ * @param bool $phpDocBoolean
+ * @param int $phpDocInteger
+ * @param float $phpDocFloat
+ * @param string $phpDocString
+ * @param array<int> $phpDocArray
+ * @param stdClass $phpDocObject
+ * @param non-empty-string $string
+ */
+function casts(
+	bool $boolean,
+	int $integer,
+	float $float,
+	string $string,
+	array $array,
+	stdClass $object,
+	?int $nullableInteger,
+	$phpDocBoolean,
+	$phpDocInteger,
+	$phpDocFloat,
+	$phpDocString,
+	$phpDocArray,
+	$phpDocObject,
+	$mixed
+): void
+{
+	$boolean;
+	$integer;
+	(float) $float;
+	(string) $string;
+	(array) $array;
+	(object) $object;
+
+	(bool) $phpDocBoolean;
+	(int) $phpDocInteger;
+	(float) $phpDocFloat;
+	(string) $phpDocString;
+	(array) $phpDocArray;
+	(object) $phpDocObject;
+
+	(string) $integer;
+	(int) $nullableInteger;
+	(int) $mixed;
+
+	if ($nullableInteger !== null) {
+		$nullableInteger;
+	}
+	if (is_int($mixed)) {
+		$mixed;
+	}
+
+	42;
+	true;
+	(string) 'value';
+	(array) [1, 2];
+	(object) new stdClass();
+	$integer + 1 * 2;
+	2 - $integer + 1;
+	$boolean || true && false;
+	$integer = 1 + 2;
+	($integer + 1) ** 2;
+	$boolean ? $integer : 0;
+	++$integer;
+	strlen($string);
+	$b = $integer-(int)-$integer;
+}
+
+class Foo
+{
+	public static function bug(string $key): void
+	{
+		$a = [$key => 1];
+
+		foreach ($a as $k => $v) {
+			$l = strlen((string)$k); // type cast is needed for auto-coerced non-decimal-int-string
+		}
+	}
+}
+
+// https://3v4l.org/krTct#v
+function doFoo() {
+	$array = [0, 1];
+	foreach ((array) $array as &$v) {
+		$v=2;
+	}
+	var_dump($array);
+}
+function doBar() {
+	$array = [0, 1];
+	foreach ($array as &$v) {
+		$v=2;
+	}
+	var_dump($array);
+}
+doFoo();
+doBar();
+
+class X {
+	public int $i;
+	public string $s;
+}
+
+function doBaz(X $x) {
+	echo $x->i;
+	echo (int) $x->s;
+
+	echo (string) $x->i;
+	echo (string) $x->s;
+}