Add PHPStan

.github/workflows/static-analysis.yml

@@ -0,0 +1,34 @@
+name: "Static Analysis"
+
+on:
+  pull_request:
+  push:
+    branches:
+      - "master"
+
+jobs:
+  static-analysis-phpstan:
+    name: "Static Analysis with PHPStan"
+    runs-on: "ubuntu-20.04"
+
+    strategy:
+      matrix:
+        php-version:
+          - "7.3"
+
+    steps:
+      - name: "Checkout code"
+        uses: "actions/checkout@v2"
+
+      - name: "Install PHP"
+        uses: "shivammathur/setup-php@v2"
+        with:
+          coverage: "none"
+          php-version: "${{ matrix.php-version }}"
+          tools: "cs2pr"
+
+      - name: "Install dependencies with Composer"
+        uses: "ramsey/composer-install@v1"
+
+      - name: "Run a static analysis with phpstan/phpstan"
+        run: "vendor/bin/phpstan analyse --error-format=checkstyle | cs2pr"

.gitignore

@@ -1,5 +1,7 @@
 /.phpcs-cache
+/.phpunit.result.cache
 /composer.lock
 /phpcs.xml
+/phpstan.neon
 /phpunit.xml
 /vendor/

composer.json

@@ -23,6 +23,9 @@
     "require-dev": {
         "doctrine/coding-standard": "^8.2",
         "pestphp/pest": "^1.0",
+        "phpstan/extension-installer": "^1.1",
+        "phpstan/phpstan": "^0.12.67",
+        "phpstan/phpstan-strict-rules": "^0.12.9",
         "symfony/var-dumper": "^5.2"
     },
     "config": {

phpstan.neon.dist

@@ -0,0 +1,5 @@
+parameters:
+    level: max
+    paths:
+        - %currentWorkingDirectory%/src
+        - %currentWorkingDirectory%/tests

src/IterableObject.php

@@ -10,16 +10,18 @@
 
 /**
  * @internal
+ *
+ * @implements IteratorAggregate<mixed>
  */
 final class IterableObject implements IteratorAggregate
 {
     /** @var iterable<mixed> */
     private $iterable;
 
-    /** @var callable */
+    /** @var callable|null */
     private $filterFn;
 
-    /** @var callable */
+    /** @var callable|null */
     private $mapFn;
 
     /**

src/iterable-functions.php

@@ -73,7 +73,7 @@ function iterable_to_traversable(iterable $iterable): Traversable
 function iterable_filter(iterable $iterable, ?callable $filter = null)
 {
     if ($filter === null) {
-        $filter = static function ($value) {
+        $filter = static function ($value): bool {
             return (bool) $value;
         };
     }
@@ -89,14 +89,14 @@ function iterable_filter(iterable $iterable, ?callable $filter = null)
  * Reduces an iterable.
  *
  * @param iterable<mixed> $iterable
- * @param callable(mixed, mixed) $reduce
+ * @param callable(mixed, mixed):mixed $reduce
  *
  * @return mixed
  *
  * @psalm-template TValue
- * @psalm-template TResult
+ * @template TResult
  * @psalm-param iterable<TValue> $iterable
- * @psalm-param callable(TResult|null, TValue) $reduce
+ * @psalm-param callable(TResult|null, TValue):TResult $reduce
  * @psalm-param TResult|null $initial
  * @psalm-return TResult|null
  */

tests/IterableFilterTest.php

@@ -16,22 +16,22 @@
     assertEquals([1 => true], iterable_to_array(iterable_filter($iterable)));
 });
 
-it('filters a Travsersable object', function (): void {
+it('filters a Traversable object', function (): void {
     $iterable = SplFixedArray::fromArray([false, true]);
     assertEquals([1 => true], iterable_to_array(iterable_filter($iterable)));
 });
 
 it('filters an array with a callback', function (): void {
     $iterable = ['foo', 'bar'];
-    $filter = static function ($input) {
+    $filter = static function ($input): bool {
         return $input === 'bar';
     };
     assertEquals([1 => 'bar'], iterable_to_array(iterable_filter($iterable, $filter)));
 });
 
 it('filters a Travsersable object with a callback', function (): void {
     $iterable = SplFixedArray::fromArray(['foo', 'bar']);
-    $filter = static function ($input) {
+    $filter = static function ($input): bool {
         return $input === 'bar';
     };
     assertEquals([1 => 'bar'], iterable_to_array(iterable_filter($iterable, $filter)));

tests/IterableObjectTest.php

@@ -5,6 +5,7 @@
 namespace BenTools\IterableFunctions\Tests;
 
 use BenTools\IterableFunctions\IterableObject;
+use Generator;
 use SplFixedArray;
 
 use function BenTools\IterableFunctions\iterable;
@@ -14,9 +15,9 @@
 use function PHPUnit\Framework\assertInstanceOf;
 use function test;
 
-$dataProvider = function () {
+$dataProvider = static function (): Generator {
     $data = ['foo', 'bar'];
-    $filter = static function ($value) {
+    $filter = static function ($value): bool {
         return $value === 'bar';
     };
     $map = 'strtoupper';
@@ -72,7 +73,7 @@
 })->with($dataProvider());
 
 it('filters the subject', function (): void {
-    $filter = static function ($value) {
+    $filter = static function ($value): bool {
         return $value === 'bar';
     };
     $iterableObject = iterable(['foo', 'bar'])->filter($filter);
@@ -87,7 +88,7 @@
 });
 
 it('combines filter and map', function (): void {
-    $filter = static function ($value) {
+    $filter = static function ($value): bool {
         return $value === 'bar';
     };
     $map = 'strtoupper';