Add RedefinedParametersRule

Author: paulbalandan

conf/config.level0.neon

@@ -75,6 +75,7 @@ rules:
 - PHPStan\Rules\Functions\InnerFunctionRule
 - PHPStan\Rules\Functions\ParamAttributesRule
 - PHPStan\Rules\Functions\PrintfParametersRule
+- PHPStan\Rules\Functions\RedefinedParametersRule
 - PHPStan\Rules\Functions\ReturnNullsafeByRefRule
 - PHPStan\Rules\Functions\VariadicParametersDeclarationRule
 - PHPStan\Rules\Keywords\ContinueBreakInLoopRule

src/Rules/Functions/RedefinedParametersRule.php

@@ -0,0 +1,57 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Functions;
+
+use PhpParser\Node;
+use PHPStan\Analyser\Scope;
+use PHPStan\Rules\Rule;
+use PHPStan\Rules\RuleErrorBuilder;
+use function count;
+use function is_string;
+use function sprintf;
+
+/**
+ * @implements Rule<Node\FunctionLike>
+ */
+class RedefinedParametersRule implements Rule
+{
+
+public function getNodeType(): string
+{
+return Node\FunctionLike::class;
+}
+
+public function processNode(Node $node, Scope $scope): array
+{
+$params = $node->getParams();
+
+if (count($params) <= 1) {
+return [];
+}
+
+$vars = [];
+$errors = [];
+
+foreach ($params as $param) {
+if (!$param->var instanceof Node\Expr\Variable) {
+continue;
+}
+
+if (!is_string($param->var->name)) {
+continue;
+}
+
+$var = $param->var->name;
+
+if (!isset($vars[$var])) {
+$vars[$var] = true;
+continue;
+}
+
+$errors[] = RuleErrorBuilder::message(sprintf('Redefinition of parameter $%s.', $var))->nonIgnorable()->build();
+}
+
+return $errors;
+}
+
+}

tests/PHPStan/Rules/Functions/RedefinedParametersRuleTest.php

@@ -0,0 +1,37 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Functions;
+
+use PHPStan\Rules\Rule;
+use PHPStan\Testing\RuleTestCase;
+
+/**
+ * @extends RuleTestCase<RedefinedParametersRule>
+ */
+class RedefinedParametersRuleTest extends RuleTestCase
+{
+
+protected function getRule(): Rule
+{
+return new RedefinedParametersRule();
+}
+
+public function testRule(): void
+{
+$this->analyse([__DIR__ . '/data/redefined-parameters.php'], [
+[
+'Redefinition of parameter $foo.',
+11,
+],
+[
+'Redefinition of parameter $bar.',
+13,
+],
+[
+'Redefinition of parameter $baz.',
+15,
+],
+]);
+}
+
+}

tests/PHPStan/Rules/Functions/data/redefined-parameters.php

@@ -0,0 +1,32 @@
+<?php declare(strict_types = 1);
+
+namespace RedefinedParameters;
+
+class HelloWorld
+{
+
+ /**
+ * @return \Closure(string, int): int
+ */
+public function foo(string $foo, string $foo): \Closure
+{
+ $callback = static fn (int $bar, array $bar): int => (int) $bar;
+
+ return function (string $baz, int $baz) use ($callback): int {
+ return $callback($baz, []);
+ };
+}
+
+ /**
+ * @return \Closure(string, bool): int
+ */
+ public function bar(string $pipe, int $count): \Closure
+ {
+ $cb = fn (int $a, string $b): int => $a + (int) $b;
+
+ return function (string $c, bool $d) use ($cb, $pipe, $count): int {
+ return $cb((int) $d, $c) + $cb($count, $pipe);
+ };
+ }
+
+}