From 584bce0eae395ea83b27fac530cbc67e0042e251 Mon Sep 17 00:00:00 2001
From: Jarred Stelfox <jarstelfox@mac.com>
Date: Mon, 15 Jul 2024 15:22:57 -0700
Subject: [PATCH] Forced Features: Implement it

This exists in the JS SDK, but not in the PHP sdk.

It's useful for cases like QA overrides during testing of features
---
 src/Growthbook.php       | 37 ++++++++++++++++++++++++++++++++++++-
 tests/GrowthbookTest.php | 14 ++++++++++++++
 2 files changed, 50 insertions(+), 1 deletion(-)

diff --git a/src/Growthbook.php b/src/Growthbook.php
index 862bf1b..24f6fb8 100644
--- a/src/Growthbook.php
+++ b/src/Growthbook.php
@@ -21,6 +21,8 @@ class Growthbook implements LoggerAwareInterface
     private $attributes = [];
     /** @var Feature<mixed>[] */
     private $features = [];
+    /** @var array<string, FeatureResult<mixed>> */
+    private $forcedFeatures = [];
     /** @var array<string,int> */
     private $forcedVariations = [];
     /** @var bool */
@@ -63,7 +65,7 @@ public static function create(): Growthbook
     }
 
     /**
-     * @param array{enabled?:bool,logger?:\Psr\Log\LoggerInterface,url?:string,attributes?:array<string,mixed>,features?:array<string,mixed>,forcedVariations?:array<string,int>,qaMode?:bool,trackingCallback?:callable,cache?:\Psr\SimpleCache\CacheInterface,httpClient?:\Psr\Http\Client\ClientInterface,requestFactory?:\Psr\Http\Message\RequestFactoryInterface,decryptionKey?:string} $options
+     * @param array{enabled?:bool,logger?:\Psr\Log\LoggerInterface,url?:string,attributes?:array<string,mixed>,features?:array<string,mixed>,forcedVariations?:array<string,int>,qaMode?:bool,trackingCallback?:callable,cache?:\Psr\SimpleCache\CacheInterface,httpClient?:\Psr\Http\Client\ClientInterface,requestFactory?:\Psr\Http\Message\RequestFactoryInterface,decryptionKey?:string,forcedFeatures?:array<string, FeatureResult<mixed>>} $options
      */
     public function __construct(array $options = [])
     {
@@ -75,6 +77,7 @@ public function __construct(array $options = [])
             "attributes",
             "features",
             "forcedVariations",
+            "forcedFeatures",
             "qaMode",
             "trackingCallback",
             "cache",
@@ -104,6 +107,10 @@ public function __construct(array $options = [])
             // Ignore errors from discovery
         }
 
+        if(array_key_exists("forcedFeatures", $options)) {
+            $this->withForcedFeatures($options['forcedFeatures']);
+        }
+
         if (array_key_exists("features", $options)) {
             $this->withFeatures(($options["features"]));
         }
@@ -155,6 +162,16 @@ public function withForcedVariations(array $forcedVariations): Growthbook
         $this->forcedVariations = $forcedVariations;
         return $this;
     }
+
+    /**
+     * @param array<string, FeatureResult<mixed>> $forcedFeatures
+     * @return Growthbook
+     */
+    public function withForcedFeatures(array $forcedFeatures)
+    {
+        $this->forcedFeatures = $forcedFeatures;
+        return $this;
+    }
     /**
      * @param string $url
      * @return Growthbook
@@ -211,6 +228,13 @@ public function getForcedVariations(): array
     {
         return $this->forcedVariations;
     }
+    /**
+     * @return array<string, FeatureResult<mixed>>
+     */
+    public function getForcedFeatured()
+    {
+        return $this->forcedFeatures;
+    }
     /**
      * @return string
      */
@@ -267,6 +291,17 @@ public function getFeature(string $key): FeatureResult
         }
         $this->log(LogLevel::DEBUG, "Evaluating feature - $key");
         $feature = $this->features[$key];
+
+        // Check if the feature is forced
+        if (array_key_exists($key, $this->forcedFeatures)) {
+            $this->log(LogLevel::DEBUG, "Feature Forced - $key", [
+                "feature" => $key,
+                "result" => $this->forcedFeatures[$key],
+            ]);
+
+            return $this->forcedFeatures[$key];
+        }
+
         if ($feature->rules) {
             foreach ($feature->rules as $rule) {
                 if ($rule->condition) {
diff --git a/tests/GrowthbookTest.php b/tests/GrowthbookTest.php
index 22ed89c..8c17b76 100644
--- a/tests/GrowthbookTest.php
+++ b/tests/GrowthbookTest.php
@@ -3,6 +3,7 @@
 require_once __DIR__ . '/../vendor/autoload.php';
 
 use Growthbook\Condition;
+use Growthbook\FeatureResult;
 use Growthbook\Growthbook;
 use Growthbook\InlineExperiment;
 use PHPUnit\Framework\TestCase;
@@ -330,6 +331,19 @@ public function testFluentInterface(): void
         );
     }
 
+    public function testForcedFeatures(): void
+    {
+        $gb = Growthbook::create()
+            ->withFeatures([
+                'feature-1'=>['defaultValue' => false, 'rules' => []]
+            ])
+            ->withForcedFeatures([
+                'feature-1' => new FeatureResult(true, 'forcedFeature')
+            ]);
+
+        $this->assertSame(true, $gb->getFeature('feature-1')->value);
+    }
+
     public function testInlineExperiment(): void
     {
         $condition = ['country'=>'US'];