Implement ArrayContainer + BDD tests

Author: e1himself

specs/array-container.spec.php

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+<?php
+
+use Psr\Container\ContainerInterface;
+use Psr\Container\NotFoundExceptionInterface;
+use Technically\ArrayContainer\Exceptions\ServiceNotFound;
+use Technically\ArrayContainer\ArrayContainer;
+
+describe('ArrayContainer', function() {
+
+    it('should instantiate a new instance', function() {
+        $container = new ArrayContainer();
+        assert($container instanceof ArrayContainer);
+    });
+
+    it('should implement PSR container interface', function() {
+        $container = new ArrayContainer();
+        assert($container instanceof ContainerInterface);
+    });
+
+    it('should instantiate a new instance with array of entries', function() {
+        $container = new ArrayContainer([
+            'a' => 'A',
+            'b' => 'B',
+        ]);
+        assert($container->has('a'));
+        assert($container->has('b'));
+        assert($container->toArray() === [
+            'a' => 'A',
+            'b' => 'B',
+        ]);
+    });
+
+    describe('->has()', function() {
+        it('should return true for defined entries', function () {
+            $container = new ArrayContainer([
+                'a' => 'A',
+                'b' => 'B',
+            ]);
+
+            assert($container->has('a') === true);
+            assert($container->has('b') === true);
+        });
+        it('should return false for entries not defined', function () {
+            $container = new ArrayContainer([
+                'a' => 'A',
+                'b' => 'B',
+            ]);
+
+            assert($container->has('A') === false);
+            assert($container->has('B') === false);
+        });
+    });
+
+    describe('->get()', function() {
+        it('should return entries by identifier', function () {
+            $now = new DateTime('now');
+            $container = new ArrayContainer([
+                'greeting' => 'Hello',
+                'date'     => $now,
+            ]);
+
+            assert($container->get('greeting') === 'Hello');
+            assert($container->get('date') === $now);
+        });
+
+        it('should throw ServiceNotFound exception for entries not defined', function () {
+            $container = new ArrayContainer(['a' => 'A']);
+
+            assert($container->has('b') === false);
+
+            try {
+                $container->get('b');
+            } catch (ServiceNotFound $exception) {
+                // passthru
+            }
+
+            assert(isset($exception));
+            assert($exception instanceof ServiceNotFound);
+            assert($exception instanceof NotFoundExceptionInterface);
+        });
+    });
+
+    describe('->set()', function() {
+        it('should set entries for identifier', function () {
+            $now = new DateTime('now');
+            $container = new ArrayContainer();
+
+            assert($container->has('date') === false);
+
+            $container->set('date', $now);
+
+            assert($container->has('date') === true);
+            assert($container->get('date') === $now);
+        });
+
+        it('should overwrite previously defined entries for the same identifier', function () {
+            $container = new ArrayContainer(['a' => 'A']);
+
+            assert($container->get('a') === 'A');
+
+            $container->set('a', 'B');
+
+            assert($container->get('a') === 'B');
+        });
+    });
+
+    describe('->toArray()', function() {
+        it('should return all container entries in array', function () {
+            $container = new ArrayContainer(['a' => 'A']);
+
+            assert($container->toArray() === ['a' => 'A']);
+
+            $container->set('b', 'B');
+
+            assert($container->toArray() === ['a' => 'A', 'b' => 'B']);
+        });
+    });
+});

src/ArrayContainer.php

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+<?php
+
+namespace Technically\ArrayContainer;
+
+use Psr\Container\ContainerInterface;
+use Technically\ArrayContainer\Exceptions\ServiceNotFound;
+
+final class ArrayContainer implements ContainerInterface
+{
+    /**
+     * @var mixed[]
+     */
+    private $services;
+
+    /**
+     * @param mixed[] $services
+     */
+    public function __construct(array $services = [])
+    {
+        $this->services = $services;
+    }
+
+    /**
+     * Returns true if the container can return an entry for the given identifier.
+     * Returns false otherwise.
+     *
+     * `has($id)` returning true does not mean that `get($id)` will not throw an exception.
+     * It does however mean that `get($id)` will not throw a `NotFoundExceptionInterface`.
+     *
+     * @param string $id Identifier of the entry to look for.
+     *
+     * @return bool
+     */
+    public function has($id)
+    {
+        return array_key_exists($id, $this->services);
+    }
+
+    /**
+     * Finds an entry of the container by its identifier and returns it.
+     *
+     * @param string $id Identifier of the entry to look for.
+     *
+     * @throws ServiceNotFound  No entry was found for **this** identifier.
+     *
+     * @return mixed Entry.
+     */
+    public function get($id)
+    {
+        if (array_key_exists($id, $this->services)) {
+            return $this->services[$id];
+        }
+
+        throw new ServiceNotFound($id);
+    }
+
+    /**
+     * Sets a container entry for the given identifier.
+     *
+     * @param string $id Identifier of the entry to set.
+     * @param mixed $entry Entry.
+     *
+     * @return void
+     */
+    public function set($id, $entry)
+    {
+        $this->services[$id] = $entry;
+    }
+
+    /**
+     * Return an associative array of all container entries.
+     *
+     * @return mixed[]
+     */
+    public function toArray(): array
+    {
+        return $this->services;
+    }
+}

src/Exceptions/ServiceNotFound.php

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+<?php
+
+namespace Technically\ArrayContainer\Exceptions;
+
+use Psr\Container\NotFoundExceptionInterface;
+use RuntimeException;
+
+final class ServiceNotFound extends RuntimeException implements NotFoundExceptionInterface
+{
+    /**
+     * @var string
+     */
+    private $serviceName;
+
+    /**
+     * @param string $serviceName
+     */
+    public function __construct(string $serviceName)
+    {
+        $this->serviceName = $serviceName;
+
+        parent::__construct("Could not resolve service (`{$serviceName}`).");
+    }
+
+    /**
+     * @return string
+     */
+    public function getServiceName(): string
+    {
+        return $this->serviceName;
+    }
+}