Refactor feature flag overrider architecture to make use of the manager pattern

.gitignore

@@ -12,3 +12,5 @@ testbench.yaml
 vendor
 node_modules
 .php-cs-fixer.cache
+
+.phpunit.result.cache

config/feature-flags.php

@@ -3,7 +3,6 @@
 declare(strict_types=1);
 
 use Worksome\FeatureFlags\ModelFeatureFlagConvertor;
-use Worksome\FeatureFlags\Overriders\ConfigOverrider;
 
 // config for Worksome/FeatureFlags
 return [
@@ -17,7 +16,7 @@
     /**
      * Overrides implementing FeatureFlagOverrider contract
      */
-    'overrider' => ConfigOverrider::class,
+    'overrider' => 'config',
 
     'providers' => [
         'launchdarkly' => [
@@ -36,24 +35,39 @@
     ],
 
     /**
-     * Overrides all feature flags directly without hitting the provider.
-     * This is particularly useful for running things in the CI,
-     * e.g. Cypress tests.
+     * List of available overriders.
+     * Key is to be used to specify which overrider should be active
      *
-     * Be careful in setting a default value as said value will be applied to all flags.
-     * Use `null` value if needing the key to be present but act as if it was not
      */
-    'override-all' => env('FEATURE_FLAGS_OVERRIDE_ALL'),
+    'overriders' => [
+        'config' => [
+            /**
+             * Overrides all feature flags directly without hitting the provider.
+             * This is particularly useful for running things in the CI,
+             * e.g. Cypress tests.
+             *
+             * Be careful in setting a default value as said value will be applied to all flags.
+             * Use `null` value if needing the key to be present but act as if it was not
+             */
+            'override-all' => null,
+
+            /**
+             * Override flags. If a feature flag is set inside an override,
+             * it will be used instead of the flag set in the provider.
+             *
+             * Usage: ['feature-flag-key' => true]
+             *
+             * Be careful in setting a default value as it will be applied.
+             * Use `null` value if needing the key to be present but act as if it was not
+             *
+             */
+            'overrides' => [
+                // ...
+            ],
+        ],
+        'in-memory' => [
+            // ...
+        ]
+    ],
 
-    /**
-     * Override flags. If a feature flag is set inside an override,
-     * it will be used instead of the flag set in the provider.
-     *
-     * Usage: ['feature-flag-key' => true]
-     *
-     * Be careful in setting a default value as it will be applied.
-     * Use `null` value if needing the key to be present but act as if it was not
-     *
-     */
-    'overrides' => [],
 ];

src/Contracts/FeatureFlagOverrider.php

@@ -13,4 +13,8 @@ public function get(FeatureFlagEnum $key): bool;
     public function hasAll(): bool;
 
     public function getAll(): bool;
+
+    public function set(FeatureFlagEnum $key, bool|null $value): static;
+
+    public function setAll(bool|null $value): static;
 }

src/FeatureFlagsApiManager.php

@@ -14,9 +14,8 @@ class FeatureFlagsApiManager extends Manager
     public function createLaunchDarklyDriver(): LaunchDarklyApiProvider
     {
         $token = $this->config->get('feature-flags.providers.launchdarkly.access-token');
-        if (! is_string($token)) {
-            throw new LaunchDarklyMissingAccessTokenException();
-        }
+
+        assert(is_string($token), new LaunchDarklyMissingAccessTokenException());
 
         return new LaunchDarklyApiProvider(
             accessToken: $token,

src/FeatureFlagsOverriderManager.php

@@ -0,0 +1,29 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Worksome\FeatureFlags;
+
+use Illuminate\Support\Manager;
+use Worksome\FeatureFlags\Overriders\ConfigOverrider;
+use Worksome\FeatureFlags\Overriders\InMemoryOverrider;
+
+class FeatureFlagsOverriderManager extends Manager
+{
+    public function createConfigDriver(): ConfigOverrider
+    {
+        return new ConfigOverrider(
+            $this->config,
+        );
+    }
+
+    public function createInMemoryDriver(): InMemoryOverrider
+    {
+        return new InMemoryOverrider();
+    }
+
+    public function getDefaultDriver(): string
+    {
+        return strval($this->config->get('feature-flags.overrider')); // @phpstan-ignore-line
+    }
+}

src/FeatureFlagsServiceProvider.php

@@ -44,16 +44,10 @@ public function register(): void
             'feature-flags'
         );
 
-        $this->app->extend(FeatureFlagsProviderContract::class, function ($provider, Container $app) {
-            return $app->makeWith(FeatureFlagsOverrideProvider::class, [
-                'provider' => $provider,
-            ]);
-        });
+        $this->app->singleton(FeatureFlagsManager::class);
+
+        $this->app->singleton(FeatureFlagsOverriderManager::class);
 
-        $this->app->singleton(
-            FeatureFlagsManager::class,
-            static fn (Container $container) => new FeatureFlagsManager($container)
-        );
 
         $this->app->singleton(FeatureFlagsProviderContract::class, function (Container $app) {
             /** @var FeatureFlagsManager $manager */
@@ -62,6 +56,22 @@ public function register(): void
             return $manager->driver();
         });
 
+        $this->app->singleton(
+            FeatureFlagOverrider::class,
+            function (Container $app) {
+                /** @var FeatureFlagsOverriderManager $manager */
+                $manager = $app->get(FeatureFlagsOverriderManager::class);
+
+                return $manager->driver();
+            }
+        );
+
+        $this->app->extend(FeatureFlagsProviderContract::class, function ($provider, Container $app) {
+            return $app->makeWith(FeatureFlagsOverrideProvider::class, [
+                'provider' => $provider,
+            ]);
+        });
+
         $this->app->singleton(FeatureFlagUserConvertor::class, function (Container $app) {
             /** @var ConfigRepository $config */
             $config = $app->get('config');
@@ -80,19 +90,6 @@ function (Container $app) {
                 return $manager->driver();
             }
         );
-
-        $this->app->singleton(
-            FeatureFlagOverrider::class,
-            function (Container $app) {
-                /** @var ConfigRepository $config */
-                $config = $app->get('config');
-
-                /** @var class-string<FeatureFlagOverrider> $convertor */
-                $convertor = $config->get('feature-flags.overrider');
-
-                return $app->get($convertor);
-            }
-        );
     }
 
     public function provides(): array

src/Overriders/ConfigOverrider.php

@@ -20,26 +20,40 @@ public function __construct(
      */
     public function has(FeatureFlagEnum $key): bool
     {
-        return $this->config->has(sprintf('feature-flags.overrides.%s', $key->value))
-               && $this->config->get(sprintf('feature-flags.overrides.%s', $key->value)) !== null;
+        return $this->config->has(sprintf('feature-flags.overriders.config.overrides.%s', $key->value))
+            && $this->config->get(sprintf('feature-flags.overriders.config.overrides.%s', $key->value)) !== null;
     }
 
     public function get(FeatureFlagEnum $key): bool
     {
-        return (bool) $this->config->get(sprintf('feature-flags.overrides.%s', $key->value));
+        return (bool) $this->config->get(sprintf('feature-flags.overriders.config.overrides.%s', $key->value));
     }
 
     /**
      * Note: null value is considered not present, will return false
      */
     public function hasAll(): bool
     {
-        return $this->config->has('feature-flags.override-all')
-               && $this->config->get('feature-flags.override-all') !== null;
+        return $this->config->has('feature-flags.overriders.config.override_all')
+            && $this->config->get('feature-flags.overriders.config.override_all') !== null;
     }
 
     public function getAll(): bool
     {
-        return (bool) $this->config->get('feature-flags.override-all');
+        return (bool) $this->config->get('feature-flags.overriders.config.override_all');
+    }
+
+    public function set(FeatureFlagEnum $key, bool|null $value): static
+    {
+        $this->config->set(sprintf('feature-flags.overriders.config.overrides.%s', $key->value), $value);
+
+        return $this;
+    }
+
+    public function setAll(bool|null $value): static
+    {
+        $this->config->set('feature-flags.overriders.config.override_all', $value);
+
+        return $this;
     }
 }

src/Overriders/InMemoryOverrider.php

@@ -0,0 +1,70 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Worksome\FeatureFlags\Overriders;
+
+use Illuminate\Support\Arr;
+use Worksome\FeatureFlags\Contracts\FeatureFlagEnum;
+use Worksome\FeatureFlags\Contracts\FeatureFlagOverrider;
+
+class InMemoryOverrider implements FeatureFlagOverrider
+{
+    /**
+     * @var array<string, bool|null> $overrides
+     */
+    private array $overrides = [];
+
+    /**
+     * @var bool|null $overrideAll
+     */
+    private bool|null $overrideAll = null;
+
+    /**
+     * Note: a flag key with null as value is considered not present, will return false
+     */
+    public function has(FeatureFlagEnum $key): bool
+    {
+        return Arr::has($this->overrides, $key->value)
+            && Arr::get($this->overrides, $key->value) !== null;
+    }
+
+    public function get(FeatureFlagEnum $key): bool
+    {
+        return (bool) Arr::get($this->overrides, $key->value, false);
+    }
+
+    /**
+     * Note: null value is considered not present, will return false
+     */
+    public function hasAll(): bool
+    {
+        return $this->overrideAll !== null;
+    }
+
+    public function getAll(): bool
+    {
+        return (bool) $this->overrideAll;
+    }
+
+    public function setAll(bool|null $value = null): static
+    {
+        $this->overrideAll = $value;
+        return $this;
+    }
+
+    public function set(FeatureFlagEnum $key, mixed $value): static
+    {
+        Arr::set($this->overrides, $key->value, $value);
+        return $this;
+    }
+
+    public function overrides(array|null $overriders): array|self
+    {
+        if ($overriders) {
+            $this->overrides = $overriders;
+            return $this;
+        }
+        return $this->overrides;
+    }
+}

src/Traits/InteractsWithFeatureFlags.php

@@ -5,12 +5,18 @@
 namespace Worksome\FeatureFlags\Traits;
 
 use Worksome\FeatureFlags\Contracts\FeatureFlagEnum;
+use Worksome\FeatureFlags\Contracts\FeatureFlagOverrider;
 
+/**
+ * This class is intended for usage mostly in testing context
+ * It provides the necessary methods to interact with the current feature flag overrider.
+ * Therefore, easily turning flag ON and OFF
+ */
 trait InteractsWithFeatureFlags
 {
-    public function switchFeatureFlag(FeatureFlagEnum $key, bool $onOff): void
+    public function switchFeatureFlag(FeatureFlagEnum $key, bool|null $onOffNull): void
     {
-        $this->app['config']->set("feature-flags.overrides.{$key->value}", $onOff);
+        $this->featureFlagOverrider()->set($key, $onOffNull);
     }
 
     public function enableFeatureFlag(FeatureFlagEnum $key): void
@@ -22,4 +28,34 @@ public function disableFeatureFlag(FeatureFlagEnum $key): void
     {
         $this->switchFeatureFlag($key, false);
     }
+
+    public function switchFeatureFlagAll(bool|null $onOffNull): void
+    {
+        $this->featureFlagOverrider()->setAll($onOffNull);
+    }
+
+    public function enableFeatureFlagAll(): void
+    {
+        $this->switchFeatureFlagAll(true);
+    }
+
+    public function disableFeatureFlagAll(): void
+    {
+        $this->switchFeatureFlagAll(false);
+    }
+
+    public function clearFeatureFlag(FeatureFlagEnum $key): void
+    {
+        $this->switchFeatureFlag($key, null);
+    }
+
+    public function clearFeatureFlagAll(): void
+    {
+        $this->switchFeatureFlagAll(null);
+    }
+
+    protected function featureFlagOverrider(): FeatureFlagOverrider
+    {
+        return $this->app->get(FeatureFlagOverrider::class);
+    }
 }