feat(experiments): ability to force experiments

Sdk.Test/FeatureClientTest.cs

@@ -50,6 +50,18 @@ public void Setup()
             var mockWorker = new Mock<IFeatureWorker>();
             mockWorker.Setup(x => x.GetRunningFeatures()).Returns(runningFeatures);
             var mockUserData = new Mock<IUserDataRepo>();
+            mockUserData.Setup(x => x.GetExperimentsForcedA()).Returns(new List<string>
+            {
+                "ALL_A-1",
+                "ALL_A-2",
+                "ALL_A-3",
+            });
+            mockUserData.Setup(x => x.GetExperimentsForcedB()).Returns(new List<string>
+            {
+                "ALL_B-1",
+                "ALL_B-2",
+                "ALL_B-3",
+            });
             mockUserData.Setup(x => x.GetUserId()).Returns(GetUuid);
             _userDataRepo = mockUserData.Object;
             _featureWorker = mockWorker.Object;
@@ -127,5 +139,57 @@ public void TestFeatureWithAllBAlwaysReturnsB()
             Assert.AreEqual(0, dictionary['A']);
             Assert.AreEqual(1000000, dictionary['B']);
         }
+
+        [Test]
+        public void TestFeatureWithOverrideExperimentsToA()
+        {
+            var dictionary = new Dictionary<char, int> {['A'] = 0, ['B'] = 0, ['X'] = 0, ['Z'] = 0};
+            var client = new FeatureClient(_featureWorker, _userDataRepo);
+            for (var i = 0; i < 100; i++)
+            {
+                var variant = client.GetVariant("ALL_A-1");
+                dictionary[variant] = dictionary[variant] + 1;
+            }
+            for (var i = 0; i < 100; i++)
+            {
+                var variant = client.GetVariant("ALL_A-2");
+                dictionary[variant] = dictionary[variant] + 1;
+            }
+            for (var i = 0; i < 100; i++)
+            {
+                var variant = client.GetVariant("ALL_A-3");
+                dictionary[variant] = dictionary[variant] + 1;
+            }
+            Assert.AreEqual(300, dictionary['A']);
+            Assert.AreEqual(0, dictionary['B']);
+            Assert.AreEqual(0, dictionary['X']);
+            Assert.AreEqual(0, dictionary['Z']);
+        }
+
+        [Test]
+        public void TestFeatureWithOverrideExperimentsToB()
+        {
+            var dictionary = new Dictionary<char, int> {['A'] = 0, ['B'] = 0, ['X'] = 0, ['Z'] = 0};
+            var client = new FeatureClient(_featureWorker, _userDataRepo);
+            for (var i = 0; i < 100; i++)
+            {
+                var variant = client.GetVariant("ALL_B-1");
+                dictionary[variant] = dictionary[variant] + 1;
+            }
+            for (var i = 0; i < 100; i++)
+            {
+                var variant = client.GetVariant("ALL_B-2");
+                dictionary[variant] = dictionary[variant] + 1;
+            }
+            for (var i = 0; i < 100; i++)
+            {
+                var variant = client.GetVariant("ALL_B-3");
+                dictionary[variant] = dictionary[variant] + 1;
+            }
+            Assert.AreEqual(300, dictionary['B']);
+            Assert.AreEqual(0, dictionary['A']);
+            Assert.AreEqual(0, dictionary['X']);
+            Assert.AreEqual(0, dictionary['Z']);
+        }
     }
 }

Sdk/FeatureContainer.cs

@@ -6,7 +6,6 @@
 using System.Threading.Tasks;
 using FossApps.FeatureManager;
 using FossApps.FeatureManager.Models;
-using Microsoft.Extensions.DependencyInjection;
 
 namespace Fossapps.FeatureManager
 {
@@ -60,11 +59,6 @@ private async Task<List<RunningFeature>> GetFeatures()
         }
     }
 
-    public interface IUserDataRepo
-    {
-        public string GetUserId();
-    }
-
     // this is scoped
     public class FeatureClient
     {
@@ -83,6 +77,14 @@ private RunningFeature GetFeatureById(string featId)
         }
         public char GetVariant(string featId)
         {
+            if (_userDataRepo.GetExperimentsForcedB().Any(x => x == featId))
+            {
+                return 'B';
+            }
+            if (_userDataRepo.GetExperimentsForcedA().Any(x => x == featId))
+            {
+                return 'A';
+            }
             var feature = GetFeatureById(featId);
 
             if (feature == null || !feature.Allocation.HasValue || string.IsNullOrEmpty(feature.RunToken) || string.IsNullOrEmpty(feature.FeatureToken))
@@ -117,21 +119,4 @@ private static int GetBucket(string userToken, string bucketToken, int numberOfB
             return (int) (number % (ulong) numberOfBuckets) + 1;
         }
     }
-
-    public static class SetupFeatures
-    {
-        public static void SetupFeatureClients<TUserDataImplementation>(this IServiceCollection collection, string endpoint, TimeSpan syncInterval) where TUserDataImplementation : class, IUserDataRepo
-        {
-            var worker = new FeatureWorker(endpoint, syncInterval);
-            worker.Init();
-            collection.AddScoped<IUserDataRepo, TUserDataImplementation>();
-            collection.AddSingleton<IFeatureWorker>(worker);
-            collection.AddScoped<FeatureClient>();
-        }
-
-        public static bool IsFeatureOn(this FeatureClient instance, string featId)
-        {
-            return instance.GetVariant(featId) == 'B';
-        }
-    }
 }

Sdk/Sdk.csproj

@@ -8,6 +8,7 @@
     </PropertyGroup>
 
     <ItemGroup>
+      <PackageReference Include="Microsoft.AspNetCore.Http.Abstractions" Version="2.2.0" />
       <PackageReference Include="Microsoft.Rest.ClientRuntime" Version="2.3.21" />
       <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="3.1.5" />
     </ItemGroup>

Sdk/SetupClient.cs

@@ -0,0 +1,22 @@
+using System;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace Fossapps.FeatureManager
+{
+    public static class SetupClient
+    {
+        public static void SetupFeatureClients<TUserDataImplementation>(this IServiceCollection collection, string endpoint, TimeSpan syncInterval) where TUserDataImplementation : class, IUserDataRepo
+        {
+            var worker = new FeatureWorker(endpoint, syncInterval);
+            worker.Init();
+            collection.AddScoped<IUserDataRepo, TUserDataImplementation>();
+            collection.AddSingleton<IFeatureWorker>(worker);
+            collection.AddScoped<FeatureClient>();
+        }
+
+        public static bool IsFeatureOn(this FeatureClient instance, string featId)
+        {
+            return instance.GetVariant(featId) == 'B';
+        }
+    }
+}

Sdk/UserDataRepo.cs

@@ -0,0 +1,51 @@
+using System.Collections.Generic;
+using System.Linq;
+using Microsoft.AspNetCore.Http;
+
+namespace Fossapps.FeatureManager
+{
+    public interface IUserDataRepo
+    {
+        public string GetUserId();
+
+        public IEnumerable<string> GetExperimentsForcedA()
+        {
+            return new List<string>();
+        }
+
+        public IEnumerable<string> GetExperimentsForcedB()
+        {
+            return new List<string>();
+        }
+    }
+    public abstract class UserDataRepoBase : IUserDataRepo
+    {
+        private readonly IHttpContextAccessor _contextAccessor;
+        public abstract string GetUserId();
+
+        protected UserDataRepoBase(IHttpContextAccessor contextAccessor)
+        {
+            _contextAccessor = contextAccessor;
+        }
+
+        public IEnumerable<string> GetExperimentsForcedA()
+        {
+            if (!_contextAccessor.HttpContext.Request.Headers.TryGetValue("X-Forced-Features-A", out var features))
+            {
+                return new List<string>();
+            }
+
+            return features.ToString().Split(",").ToList();
+        }
+
+        public IEnumerable<string> GetExperimentsForcedB()
+        {
+            if (!_contextAccessor.HttpContext.Request.Headers.TryGetValue("X-Forced-Features-B", out var features))
+            {
+                return new List<string>();
+            }
+
+            return features.ToString().Split(",").ToList();
+        }
+    }
+}