init: add code/tests

Author: simpletoimplement

README.md

@@ -1 +1,37 @@
-# queue
+<p align="center">
+  <a href="https://github.com/phpsimple"><img src="https://avatars.githubusercontent.com/u/120518417?s=84&v=4"></a><br>
+</p>
+
+<h1 align="center">Queue</h1>
+
+<p align="center">Very simple FIFO queue implementation</p>
+
+[![Test Coverage](https://api.codeclimate.com/v1/badges/9487615798456eafda6c/test_coverage)](https://codeclimate.com/github/phpsimple/queue/test_coverage)
+
+---
+
+Installation
+---
+The recommended way to install is via Composer:
+
+```shell
+composer require phpsimple/queue
+```
+
+Usage
+---
+```php
+use PhpSimple\Queue;
+
+$queue = new Queue();
+
+for ($i = 0; $i < 10; $i++) {
+    $queue->push($i);
+}
+
+while ($item = $queue->pop()) {
+    var_dump($item);
+}
+```
+---
+[![Stand With Ukraine](https://raw.githubusercontent.com/vshymanskyy/StandWithUkraine/main/banner2-direct.svg)](https://vshymanskyy.github.io/StandWithUkraine)

composer.json

@@ -24,7 +24,7 @@
     },
     "autoload": {
         "psr-4": {
-            "Phpsimple\\": "src/"
+            "PhpSimple\\": "src/"
         }
     },
     "autoload-dev": {

phpunit.xml.dist

@@ -1,13 +1,13 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <phpunit
-         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.5/phpunit.xsd"
-         backupGlobals="false"
-         bootstrap="vendor/autoload.php"
-         cacheResult="false"
-         colors="true"
-         failOnRisky="true"
-         failOnWarning="true"
+     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+     xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.5/phpunit.xsd"
+     backupGlobals="false"
+     bootstrap="vendor/autoload.php"
+     cacheResult="false"
+     colors="true"
+     failOnRisky="true"
+     failOnWarning="true"
 >
     <testsuites>
         <testsuite name="default">

src/Queue.php

@@ -0,0 +1,61 @@
+<?php declare(strict_types = 1);
+
+namespace PhpSimple;
+
+use Countable;
+
+use function array_shift;
+use function count;
+use function current;
+use function in_array;
+
+/**
+ * @template Q
+ */
+final class Queue implements Countable
+{
+    public function __construct(/** @var array<Q> */ private array $items = [])
+    {
+    }
+
+    public function clear(): void
+    {
+        $this->items = [];
+    }
+
+    public function contains(mixed $item): bool
+    {
+        return in_array(needle: $item, haystack: $this->items, strict: true);
+    }
+
+    public function pop(): mixed
+    {
+        if ($this->isEmpty()) {
+            return false;
+        }
+
+        return array_shift(array: $this->items);
+    }
+
+    public function push(mixed $item): void
+    {
+        if (null !== $item) {
+            $this->items[] = $item;
+        }
+    }
+
+    public function peek(): mixed
+    {
+        return current(array: $this->items);
+    }
+
+    public function isEmpty(): bool
+    {
+        return [] === $this->items;
+    }
+
+    public function count(): int
+    {
+        return count(value: $this->items);
+    }
+}

tests/src/QueueTest.php

@@ -0,0 +1,35 @@
+<?php declare(strict_types = 1);
+
+namespace PhpSimple\Tests;
+
+use PhpSimple\Queue;
+use PHPUnit\Framework\TestCase;
+
+class QueueTest extends TestCase
+{
+    public function testQueue(): void
+    {
+        $queue = new Queue();
+
+        $this->assertCount(expectedCount: 0, haystack: $queue);
+        $this->assertTrue(condition: $queue->isEmpty());
+
+        $queue->push(item: 1);
+        $queue->push(item: 2);
+        $queue->push(item: 3);
+
+        $this->assertCount(expectedCount: 3, haystack: $queue);
+        $this->assertFalse(condition: $queue->isEmpty());
+        $this->assertTrue(condition: $queue->contains(item: 1));
+
+        $queue->pop();
+
+        $this->assertCount(expectedCount: 2, haystack: $queue);
+        $this->assertEquals(expected: 2, actual: $queue->peek());
+
+        $queue->clear();
+        $this->assertCount(expectedCount: 0, haystack: $queue);
+
+        $this->assertFalse(condition: $queue->pop());
+    }
+}