Mark LockBackendInterface::acquire() as impure (#736)

* test lock backend impure acquire

* add stub

* fix assertions

Author: mglaman

stubs/Drupal/Core/Lock/LockBackendInterface.stub

@@ -0,0 +1,18 @@
+<?php
+
+namespace Drupal\Core\Lock;
+
+interface LockBackendInterface {
+
+  /**
+   * @param string $name
+   * @param float $timeout
+   *
+   * @return bool
+   *
+   * @phpstan-impure
+   */
+  public function acquire(string $name, float $timeout = 30.0): bool;
+
+
+}

tests/src/Type/LockBackendInterfaceStubTest.php

@@ -0,0 +1,31 @@
+<?php declare(strict_types=1);
+
+namespace mglaman\PHPStanDrupal\Tests\Type;
+
+use mglaman\PHPStanDrupal\Tests\AdditionalConfigFilesTrait;
+use PHPStan\Testing\TypeInferenceTestCase;
+
+final class LockBackendInterfaceStubTest extends TypeInferenceTestCase
+{
+    use AdditionalConfigFilesTrait;
+
+    public function dataFileAsserts(): iterable
+    {
+        yield from self::gatherAssertTypes(__DIR__ . '/data/lock-backend.php');
+    }
+
+    /**
+     * @dataProvider dataFileAsserts
+     * @param string $assertType
+     * @param string $file
+     * @param mixed ...$args
+     */
+    public function testFileAsserts(
+        string $assertType,
+        string $file,
+        ...$args
+    ): void
+    {
+        $this->assertFileAsserts($assertType, $file, ...$args);
+    }
+}

tests/src/Type/data/lock-backend.php

@@ -0,0 +1,14 @@
+<?php
+
+namespace Foo;
+
+use function PHPStan\Testing\assertType;
+
+$lock = \Drupal::lock();
+
+if (!$lock->acquire('foo')) {
+    assertType('bool', $lock->acquire('foo'));
+    if ($lock->acquire('foo')) {
+        assertType('bool', $lock->acquire('foo'));
+    }
+}