Feature Toggle Refactor (#24)

docs/components/feature-toggle/index.md

@@ -7,3 +7,42 @@ title: Feature Toggle - Overview
 ```shell
 composer require sonsofphp/feature-toggle
 ```
+
+## Usage
+
+```php
+use SonsOfPHP\Component\FeatureToggle\Feature;
+use SonsOfPHP\Component\FeatureToggle\Provider\InMemoryFeatureToggleProvider;
+use SonsOfPHP\Component\FeatureToggle\Toggle\AlwaysEnabledToggle;
+
+// Using a feature toggle provider
+$provider = new InMemoryFeatureToggleProvider();
+$provider->addFeature(new Feature('feature.example', new AlwaysEnabledToggle()));
+
+$feature = $provider->getFeatureToggleByKey('feature.example');
+
+// Checking if the feature is enabled
+$isEnabled = $feature->isEnabled();
+```
+
+## Advanced Usage
+
+```php
+// ...
+use SonsOfPHP\Component\FeatureToggle\Context;
+
+// Different ways to build the context, the context
+// is used by the Toggle
+$context = new Context([
+    'user' => $user,
+]);
+$context->set('user', $user);
+$context['user'] = $user;
+
+$isEnabled = $feature->isEnabled($context);
+```
+
+## Create your own Toggle
+
+Take a look at the `AlwaysEnabledToggle` and `AlwaysDisabledToggle`. This is how
+more complex Toggles can be created. These two are as simple as you can get.

packages/feature-toggle/Context.php

@@ -9,26 +9,56 @@
  */
 final class Context implements ContextInterface
 {
-    private array $data = [];
+    public function __construct(private array $data = []) {}
 
-    public function get(string $key)
+    public function offsetSet($offset, $value): void
     {
-        if ($this->has($key)) {
-            return $this->data[$key];
+        if (null === $offset) {
+            throw new \Exception('Requires a key');
         }
 
-        return null;
+        $this->data[$offset] = $value;
+    }
+
+    public function offsetExists($offset): bool
+    {
+        return \array_key_exists($offset, $this->data);
+    }
+
+    public function offsetUnset($offset): void
+    {
+        unset($this->data[$offset]);
+    }
+
+    public function offsetGet($offset): mixed
+    {
+        return $this->data[$offset] ?? null;
+    }
+
+    public function getIterator(): \Traversable
+    {
+        return new \ArrayIterator($this->data);
+    }
+
+    public function jsonSerialize(): mixed
+    {
+        return $this->data;
+    }
+
+    public function get(string $key): mixed
+    {
+        return $this->offsetGet($key);
     }
 
     public function set(string $key, $value): ContextInterface
     {
-        $this->data[$key] = $value;
+        $this->offsetSet($key, $value);
 
         return $this;
     }
 
     public function has(string $key): bool
     {
-        return \array_key_exists($key, $this->data);
+        return $this->offsetExists($key);
     }
 }

packages/feature-toggle/ContextInterface.php

@@ -7,7 +7,7 @@
 /**
  * @author Joshua Estes <[email protected]>
  */
-interface ContextInterface
+interface ContextInterface extends \ArrayAccess, \IteratorAggregate, \JsonSerializable
 {
     public function get(string $key);
 

packages/feature-toggle/Feature.php

@@ -25,7 +25,7 @@ public function getKey(): string
         return $this->key;
     }
 
-    public function isEnabled(ContextInterface $context): bool
+    public function isEnabled(?ContextInterface $context = null): bool
     {
         return $this->toggle->isEnabled($context);
     }

packages/feature-toggle/FeatureInterface.php

@@ -9,17 +9,12 @@
  *
  * @author Joshua Estes <[email protected]>
  */
-interface FeatureInterface
+interface FeatureInterface extends ToggleInterface
 {
     /**
      * Returns the key that is used for the feature toggle. The key should be
      * unique enough that you can say "is_granted('feature_toggle_key')" and not
      * get them all mixed up.
      */
     public function getKey(): string;
-
-    /**
-     * Returns true or false if the toggle is enabled.
-     */
-    public function isEnabled(ContextInterface $context): bool;
 }

packages/feature-toggle/Provider/FeatureToggleProviderInterface.php

@@ -16,8 +16,5 @@
  */
 interface FeatureToggleProviderInterface
 {
-    /**
-     * @return FeatureInterface[]
-     */
-    public function getFeatures(): iterable;
+    public function getFeatureToggleByKey(string $key): ?FeatureInterface;
 }

packages/feature-toggle/Provider/InMemoryFeatureToggleProvider.php

@@ -13,7 +13,7 @@ final class InMemoryFeatureToggleProvider implements FeatureToggleProviderInterf
 {
     private array $features = [];
 
-    public function __construct($features = [])
+    public function __construct(array $features = [])
     {
         foreach ($features as $feature) {
             $this->addFeature($feature);
@@ -22,11 +22,15 @@ public function __construct($features = [])
 
     public function addFeature(FeatureInterface $feature): void
     {
-        $this->features[] = $feature;
+        $this->features[$feature->getKey()] = $feature;
     }
 
-    public function getFeatures(): iterable
+    public function getFeatureToggleByKey(string $key): ?FeatureInterface
     {
-        yield from $this->features;
+        if (isset($this->features[$key])) {
+            return $this->features[$key];
+        }
+
+        return null;
     }
 }

packages/feature-toggle/Tests/Provider/InMemoryFeatureToggleProviderTest.php

@@ -9,6 +9,7 @@
 use SonsOfPHP\Component\FeatureToggle\Provider\FeatureToggleProviderInterface;
 use SonsOfPHP\Component\FeatureToggle\Provider\InMemoryFeatureToggleProvider;
 use SonsOfPHP\Component\FeatureToggle\ToggleInterface;
+use PHPUnit\Framework\MockObject;
 
 /**
  * @coversDefaultClass \SonsOfPHP\Component\FeatureToggle\Provider\InMemoryFeatureToggleProvider
@@ -17,7 +18,7 @@
  */
 final class InMemoryFeatureToggleProviderTest extends TestCase
 {
-    private $toggle;
+    private MockObject|ToggleInterface $toggle;
 
     protected function setUp(): void
     {
@@ -37,7 +38,7 @@ public function testItHasTheCorrectInterface(): void
     /**
      * @covers ::__construct
      * @covers ::addFeature
-     * @covers ::getFeatures
+     * @covers ::getFeatureToggleByKey
      */
     public function testAddingFeatures(): void
     {
@@ -48,6 +49,8 @@ public function testAddingFeatures(): void
 
         $provider = new InMemoryFeatureToggleProvider($features);
 
-        $this->assertCount(2, iterator_to_array($provider->getFeatures()));
+        $this->assertNotNull($provider->getFeatureToggleByKey('test.one'));
+        $this->assertNotNull($provider->getFeatureToggleByKey('test.two'));
+        $this->assertNull($provider->getFeatureToggleByKey('test.three'));
     }
 }

packages/feature-toggle/Toggle/AlwaysDisabledToggle.php

@@ -14,7 +14,7 @@
  */
 class AlwaysDisabledToggle implements ToggleInterface
 {
-    public function isEnabled(ContextInterface $context): bool
+    public function isEnabled(?ContextInterface $context = null): bool
     {
         return false;
     }

packages/feature-toggle/Toggle/AlwaysEnabledToggle.php

@@ -14,7 +14,7 @@
  */
 class AlwaysEnabledToggle implements ToggleInterface
 {
-    public function isEnabled(ContextInterface $context): bool
+    public function isEnabled(?ContextInterface $context = null): bool
     {
         return true;
     }

packages/feature-toggle/ToggleInterface.php

@@ -12,5 +12,5 @@ interface ToggleInterface
     /**
      * Returns true if this strategy is enabled.
      */
-    public function isEnabled(ContextInterface $context): bool;
+    public function isEnabled(?ContextInterface $context = null): bool;
 }