Enhancement: Implement Closures\NoParameterWithNullableTypeDeclarationRule

CHANGELOG.md

@@ -25,6 +25,8 @@ For a full diff see [`0.2.0...master`](https://github.com/localheinz/phpstan-rul
 * added `Methods\NoParameterWithNullDefaultValueRule`, which reports an
   error when a method declared on an anonymous class, a class, or an interface
   has a parameter with `null` as default value ([#32](https://github.com/localheinz/phpstan-rules/pull/32)), by [@localheinz](https://github.com/localheinz)
+* added `Closures\NoParameterWithNullableTypeDeclarationRule`, which reports an
+  error when a closure has a parameter with a nullable type declaration ([#33](https://github.com/localheinz/phpstan-rules/pull/33)), by [@localheinz](https://github.com/localheinz)
 
 ## [`0.2.0`](https://github.com/localheinz/phpstan-rules/releases/tag/0.2.0)
 

README.md

@@ -22,6 +22,7 @@ This package provides the following rules for use with [`phpstan/phpstan`](https
 * [`Localheinz\PHPStan\Rules\Classes\AbstractOrFinalRule`](https://github.com/localheinz/phpstan-rules#classesabstractorfinalrule)
 * [`Localheinz\PHPStan\Rules\Classes\FinalRule`](https://github.com/localheinz/phpstan-rules#classesfinalrule)
 * [`Localheinz\PHPStan\Rules\Closures\NoNullableReturnTypeDeclarationRule`](https://github.com/localheinz/phpstan-rules#closuresnonullablereturntypedeclarationrule)
+* [`Localheinz\PHPStan\Rules\Closures\NoParameterWithNullableTypeDeclarationRule`](https://github.com/localheinz/phpstan-rules#closuresnoparameterwithnullabletypedeclarationrule)
 * [`Localheinz\PHPStan\Rules\Closures\NoParameterWithNullDefaultValueRule`](https://github.com/localheinz/phpstan-rules#closuresnoparameterwithnulldefaultvaluerule)
 * [`Localheinz\PHPStan\Rules\Functions\NoNullableReturnTypeDeclarationRule`](https://github.com/localheinz/phpstan-rules#functionsnonullablereturntypedeclarationrule)
 * [`Localheinz\PHPStan\Rules\Functions\NoParameterWithNullDefaultValueRule`](https://github.com/localheinz/phpstan-rules#functionsnoparameterwithnulldefaultvaluerule)
@@ -89,6 +90,17 @@ rules:
 	- Localheinz\PHPStan\Rules\Closures\NoNullableReturnTypeDeclarationRule
 ```
 
+### `Closures\NoParameterWithNullableTypeDeclarationRule`
+
+This rule reports an error when a closure has a parameter with a nullable type declaration.
+
+If you want to use this rule, add it to your `phpstan.neon`:
+
+```neon
+rules:
+	- Localheinz\PHPStan\Rules\Closures\NoParameterWithNullableTypeDeclarationRule
+```
+
 ### `Closures\NoParameterWithNullDefaultValueRule`
 
 This rule reports an error when a closure has a parameter with `null` as default value.

phpstan.neon

@@ -4,6 +4,7 @@ includes:
 rules:
 	- Localheinz\PHPStan\Rules\Classes\AbstractOrFinalRule
 	- Localheinz\PHPStan\Rules\Closures\NoNullableReturnTypeDeclarationRule
+	- Localheinz\PHPStan\Rules\Closures\NoParameterWithNullableTypeDeclarationRule
 	- Localheinz\PHPStan\Rules\Functions\NoNullableReturnTypeDeclarationRule
 	- Localheinz\PHPStan\Rules\Functions\NoParameterWithNullDefaultValueRule
 	- Localheinz\PHPStan\Rules\Methods\NoNullableReturnTypeDeclarationRule

src/Closures/NoParameterWithNullableTypeDeclarationRule.php

@@ -0,0 +1,60 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * Copyright (c) 2018 Andreas Möller.
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ *
+ * @see https://github.com/localheinz/phpstan-rules
+ */
+
+namespace Localheinz\PHPStan\Rules\Closures;
+
+use PhpParser\Node;
+use PHPStan\Analyser\Scope;
+use PHPStan\Rules\Rule;
+
+final class NoParameterWithNullableTypeDeclarationRule implements Rule
+{
+    public function getNodeType(): string
+    {
+        return Node\Expr\Closure::class;
+    }
+
+    /**
+     * @param Node\Expr\Closure $node
+     * @param Scope             $scope
+     *
+     * @return array
+     */
+    public function processNode(Node $node, Scope $scope): array
+    {
+        if (0 === \count($node->params)) {
+            return [];
+        }
+
+        $params = \array_filter($node->params, static function (Node\Param $node): bool {
+            return $node->type instanceof Node\NullableType;
+        });
+
+        if (0 === \count($params)) {
+            return [];
+        }
+
+        return \array_map(static function (Node\Param $node): string {
+            /** @var Node\Expr\Variable $variable */
+            $variable = $node->var;
+
+            /** @var string $parameterName */
+            $parameterName = $variable->name;
+
+            return \sprintf(
+                'Parameter "$%s" of closure should not have a nullable type declaration.',
+                $parameterName
+            );
+        }, $params);
+    }
+}

test/Fixture/Closures/NoParameterWithNullableTypeDeclarationRule/Failure/closure-with-parameter-with-nullable-type-declaration.php

@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Localheinz\PHPStan\Rules\Test\Fixture\Closures\NoParameterWithNullDefaultValueRule\Success;
+
+$foo = function (?string $bar) {
+    return $bar;
+};

test/Fixture/Closures/NoParameterWithNullableTypeDeclarationRule/Success/closure-with-parameter-with-type-declaration.php

@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Localheinz\PHPStan\Rules\Test\Fixture\Closures\NoParameterWithNullDefaultValueRule\Success;
+
+$foo = function (string $bar) {
+    return $bar;
+};

test/Fixture/Closures/NoParameterWithNullableTypeDeclarationRule/Success/closure-with-parameter-without-type-declaration.php

@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Localheinz\PHPStan\Rules\Test\Fixture\Closures\NoParameterWithNullDefaultValueRule\Success;
+
+$foo = function ($bar) {
+    return $bar;
+};

test/Fixture/Closures/NoParameterWithNullableTypeDeclarationRule/Success/closure-without-parameters.php

@@ -0,0 +1,8 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Localheinz\PHPStan\Rules\Test\Fixture\Closures\NoParameterWithNullDefaultValueRule\Success;
+
+$foo = function () {
+};

test/Integration/Closures/NoParameterWithNullableTypeDeclarationRuleTest.php

@@ -0,0 +1,64 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * Copyright (c) 2018 Andreas Möller.
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ *
+ * @see https://github.com/localheinz/phpstan-rules
+ */
+
+namespace Localheinz\PHPStan\Rules\Test\Integration\Closures;
+
+use Localheinz\PHPStan\Rules\Closures\NoParameterWithNullableTypeDeclarationRule;
+use Localheinz\PHPStan\Rules\Test\Integration\AbstractTestCase;
+use PHPStan\Rules\Rule;
+
+/**
+ * @internal
+ */
+final class NoParameterWithNullableTypeDeclarationRuleTest extends AbstractTestCase
+{
+    public function providerAnalysisSucceeds(): \Generator
+    {
+        $paths = [
+            'closure-with-parameter-with-type-declaration' => __DIR__ . '/../../Fixture/Closures/NoParameterWithNullableTypeDeclarationRule/Success/closure-with-parameter-with-type-declaration.php',
+            'closure-with-parameter-without-type-declaration' => __DIR__ . '/../../Fixture/Closures/NoParameterWithNullableTypeDeclarationRule/Success/closure-with-parameter-without-type-declaration.php',
+            'closure-without-parameters' => __DIR__ . '/../../Fixture/Closures/NoParameterWithNullableTypeDeclarationRule/Success/closure-without-parameters.php',
+        ];
+
+        foreach ($paths as $description => $path) {
+            yield $description => [
+                $path,
+            ];
+        }
+    }
+
+    public function providerAnalysisFails(): \Generator
+    {
+        $paths = [
+            'closure-with-parameter-with-nullable-type-declaration' => [
+                __DIR__ . '/../../Fixture/Closures/NoParameterWithNullableTypeDeclarationRule/Failure/closure-with-parameter-with-nullable-type-declaration.php',
+                [
+                    'Parameter "$bar" of closure should not have a nullable type declaration.',
+                    7,
+                ],
+            ],
+        ];
+
+        foreach ($paths as $description => [$path, $error]) {
+            yield $description => [
+                $path,
+                $error,
+            ];
+        }
+    }
+
+    protected function getRule(): Rule
+    {
+        return new NoParameterWithNullableTypeDeclarationRule();
+    }
+}