feat(Unleash): add Unleash provider

.github/component_owners.yml

@@ -27,6 +27,8 @@ components:
   src/OpenFeature.Providers.Ofrep:
     - askpt
     - weyert
+  src/OpenFeature.Providers.Unleash:
+    - PSanetra
 
   # test/
   test/OpenFeature.Providers.Flagd.Test:
@@ -55,6 +57,8 @@ components:
   test/OpenFeature.Providers.Ofrep.Test:
     - askpt
     - weyert
+  test/OpenFeature.Providers.Unleash.Test:
+    - PSanetra
 
 ignored-authors:
   - renovate-bot

.release-please-manifest.json

@@ -8,5 +8,6 @@
   "src/OpenFeature.Contrib.Providers.EnvVar": "0.0.7",
   "src/OpenFeature.Providers.Flagd": "0.6.1",
   "src/OpenFeature.Providers.Ofrep": "0.1.5",
-  "src/OpenFeature.Providers.GOFeatureFlag": "1.0.0"
-}
+  "src/OpenFeature.Providers.GOFeatureFlag": "1.0.0",
+  "src/OpenFeature.Providers.Unleash": "0.1.0"
+}

DotnetSdkContrib.slnx

@@ -9,6 +9,7 @@
     <Project Path="src/OpenFeature.Contrib.Providers.Statsig/OpenFeature.Contrib.Providers.Statsig.csproj" />
     <Project Path="src/OpenFeature.Providers.Ofrep/OpenFeature.Providers.Ofrep.csproj" />
     <Project Path="src/OpenFeature.Providers.GOFeatureFlag/OpenFeature.Providers.GOFeatureFlag.csproj" />
+    <Project Path="src\OpenFeature.Providers.Unleash\OpenFeature.Providers.Unleash.csproj" />
   </Folder>
   <Folder Name="/test/">
     <Project Path="test/OpenFeature.Contrib.Providers.ConfigCat.Test/OpenFeature.Contrib.Providers.ConfigCat.Test.csproj" />
@@ -23,5 +24,6 @@
     <Project Path="test/OpenFeature.Contrib.Providers.Statsig.Test/OpenFeature.Contrib.Providers.Statsig.Test.csproj" />
     <Project Path="test/OpenFeature.Providers.Ofrep.Test/OpenFeature.Providers.Ofrep.Test.csproj" />
     <Project Path="test/OpenFeature.Providers.GOFeatureFlag.Test/OpenFeature.Providers.GOFeatureFlag.Test.csproj" />
+    <Project Path="test\OpenFeature.Providers.Unleash.Test\OpenFeature.Providers.Unleash.Test.csproj" />
   </Folder>
 </Solution>

release-please-config.json

@@ -93,6 +93,16 @@
       "extra-files": [
         "OpenFeature.Providers.Ofrep.csproj"
       ]
+    },
+    "src/OpenFeature.Providers.Unleash": {
+      "package-name": "OpenFeature.Providers.Unleash",
+      "release-type": "simple",
+      "bump-minor-pre-major": true,
+      "bump-patch-for-minor-pre-major": true,
+      "versioning": "default",
+      "extra-files": [
+        "OpenFeature.Providers.Unleash.csproj"
+      ]
     }
   },
   "changelog-sections": [

src/OpenFeature.Providers.Unleash/EvaluationContextExtensions.cs

@@ -0,0 +1,106 @@
+using System;
+using System.Collections.Generic;
+using OpenFeature.Model;
+using Unleash;
+
+namespace OpenFeature.Providers.Unleash;
+
+/// <summary>
+/// Extension methods for transforming an OpenFeature EvaluationContext into an Unleash UnleashContext.
+/// </summary>
+internal static class EvaluationContextExtensions
+{
+    private const string UserIdKey = "userId";
+    private const string SessionIdKey = "sessionId";
+    private const string RemoteAddressKey = "remoteAddress";
+    private const string EnvironmentKey = "environment";
+    private const string AppNameKey = "appName";
+    private const string CurrentTimeKey = "currentTime";
+
+    /// <summary>
+    /// Gets the appName value from the evaluation context, or null if not present.
+    /// </summary>
+    /// <param name="context">The evaluation context.</param>
+    /// <returns>The appName value, or null.</returns>
+    public static string? GetAppName(this EvaluationContext? context)
+    {
+        if (context == null)
+        {
+            return null;
+        }
+
+        return context.TryGetValue(AppNameKey, out var value) ? value?.AsString : null;
+    }
+
+    /// <summary>
+    /// Transforms an OpenFeature EvaluationContext into an Unleash UnleashContext.
+    /// </summary>
+    /// <param name="context">The evaluation context, may be null.</param>
+    /// <returns>A new UnleashContext populated from the context.</returns>
+    public static UnleashContext ToUnleashContext(this EvaluationContext? context)
+    {
+        if (context == null)
+        {
+            return new UnleashContext();
+        }
+
+        string? userId = null;
+        string? sessionId = null;
+        string? remoteAddress = null;
+        string? environment = null;
+        string? appName = null;
+        DateTimeOffset? currentTime = null;
+        var properties = new Dictionary<string, string>();
+
+        if (!string.IsNullOrWhiteSpace(context.TargetingKey))
+        {
+            userId = context.TargetingKey;
+        }
+
+        foreach (var kvp in context)
+        {
+            var key = kvp.Key;
+            var value = kvp.Value;
+
+            if (value == null)
+            {
+                continue;
+            }
+
+            var stringValue = value.AsString;
+
+            switch (key)
+            {
+                case UserIdKey:
+                    userId = stringValue;
+                    break;
+                case SessionIdKey:
+                    sessionId = stringValue;
+                    break;
+                case RemoteAddressKey:
+                    remoteAddress = stringValue;
+                    break;
+                case EnvironmentKey:
+                    environment = stringValue;
+                    break;
+                case AppNameKey:
+                    appName = stringValue;
+                    break;
+                case CurrentTimeKey:
+                    if (DateTimeOffset.TryParse(stringValue, out var parsed))
+                    {
+                        currentTime = parsed;
+                    }
+                    break;
+                default:
+                    if (stringValue != null)
+                    {
+                        properties[key] = stringValue;
+                    }
+                    break;
+            }
+        }
+
+        return new UnleashContext(appName, environment, userId, sessionId, remoteAddress, currentTime, properties);
+    }
+}

src/OpenFeature.Providers.Unleash/OpenFeature.Providers.Unleash.csproj

@@ -0,0 +1,37 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <PackageId>OpenFeature.Providers.Unleash</PackageId>
+    <VersionNumber>0.1.0</VersionNumber> <!--x-release-please-version -->
+    <VersionPrefix>$(VersionNumber)</VersionPrefix>
+    <AssemblyVersion>$(VersionNumber)</AssemblyVersion>
+    <FileVersion>$(VersionNumber)</FileVersion>
+    <Description>Unleash provider for OpenFeature .NET SDK</Description>
+    <Authors>OpenFeature Authors</Authors>
+    <GenerateDocumentationFile>true</GenerateDocumentationFile>
+    <PackageReadmeFile>README.md</PackageReadmeFile>
+    <RootNamespace>OpenFeature.Providers.Unleash</RootNamespace>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <!-- documentation -->
+  <ItemGroup>
+    <None Include="README.md" Pack="true" PackagePath="\" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <!-- make the internal methods visible to our test project -->
+    <AssemblyAttribute Include="System.Runtime.CompilerServices.InternalsVisibleTo">
+      <_Parameter1>$(MSBuildProjectName).Test</_Parameter1>
+    </AssemblyAttribute>
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Unleash.Client" Version="[6.2.1,7.0)" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="OpenFeature" Version="[2.0,3.0)" />
+  </ItemGroup>
+
+</Project>

src/OpenFeature.Providers.Unleash/README.md

@@ -0,0 +1,112 @@
+# Unleash .NET Provider
+
+The Unleash provider allows you to use [Unleash](https://www.getunleash.io/) with the OpenFeature .NET SDK.
+
+# .Net SDK usage
+
+## Requirements
+
+- open-feature/dotnet-sdk v2.x
+- Unleash .NET SDK v6.x
+
+## Install dependencies
+
+The first thing we will do is install the **OpenFeature SDK** and the **Unleash Feature Flag provider**.
+
+### .NET Cli
+
+```shell
+dotnet add package OpenFeature.Providers.Unleash
+```
+
+### Package Manager
+
+```shell
+NuGet\Install-Package OpenFeature.Providers.Unleash
+```
+
+### Package Reference
+
+```xml
+<PackageReference Include="OpenFeature.Providers.Unleash" />
+```
+
+### Packet cli
+
+```shell
+paket add OpenFeature.Providers.Unleash
+```
+
+### Cake
+
+```shell
+// Install OpenFeature.Providers.Unleash as a Cake Addin
+#addin nuget:?package=OpenFeature.Providers.Unleash
+
+// Install OpenFeature.Providers.Unleash as a Cake Tool
+#tool nuget:?package=OpenFeature.Providers.Unleash
+```
+
+## Using the Unleash Provider with the OpenFeature SDK
+
+```csharp
+using OpenFeature;
+using OpenFeature.Providers.Unleash;
+using Unleash;
+
+var settings = new UnleashSettings
+{
+    AppName = "my-app",
+    UnleashApi = new Uri("http://localhost:4242/api/"),
+    CustomHttpHeaders = new Dictionary<string, string>
+    {
+        { "Authorization", "*:development.your-api-token" }
+    }
+};
+
+var provider = new UnleashProvider(settings);
+
+// Set the provider for the OpenFeature SDK
+await Api.Instance.SetProviderAsync(provider);
+
+// Get an OpenFeature client
+var client = Api.Instance.GetClient();
+
+// Boolean evaluation (uses IsEnabled)
+var enabled = await client.GetBooleanValueAsync("my-feature", false);
+
+// String evaluation (uses variant payload)
+var value = await client.GetStringValueAsync("my-variant-flag", "default");
+
+// Integer evaluation (parses variant payload)
+var count = await client.GetIntegerValueAsync("my-int-flag", 0);
+
+// Double evaluation (parses variant payload)
+var rate = await client.GetDoubleValueAsync("my-double-flag", 0.0);
+```
+
+## EvaluationContext and Unleash Context relationship
+
+The provider maps OpenFeature `EvaluationContext` fields to `UnleashContext`:
+
+| EvaluationContext Key | Unleash Context Field |
+|-----------------------|------------------------|
+| `TargetingKey`        | `UserId`               |
+| `sessionId`           | `SessionId`            |
+| `remoteAddress`       | `RemoteAddress`        |
+| `environment`         | `Environment`          |
+| `appName`             | `AppName`              |
+| `currentTime`         | `CurrentTime`          |
+| All other keys        | `Properties`           |
+
+## Variant payload type metadata
+
+When evaluating variants (string, integer, double, structure), the provider exposes the Unleash payload `type` field (e.g., `"string"`, `"number"`, `"json"`, `"csv"`) as `payload-type` in the resolution details flag metadata.
+
+## Events
+
+The provider emits `ProviderConfigurationChanged` events when Unleash fires `TogglesUpdatedEvent` (i.e., when toggle state is refreshed from the server).
+
+## Known issues and limitations
+
+- The provider does not accept an external `IUnleash` instance because lifecycle events (`ReadyEvent`, `ErrorEvent`, `TogglesUpdatedEvent`) can only be subscribed during client construction.