Prepare v8.0.0-preview1 release (#67)

* Reduce memory allocation in async hot paths (where sync completion is likely)

* Back IConfigCatLogger.LogLevel with a volatile field as it may be accessed from multiple threads

* Revise XML documentation to improve consistency and wording (with special regard to terminology)

* Enable Source Link and deterministic build

* Get rid of redundant release notes in CHANGELOG.md

* Clean up usings

* Remove unused code

* Reduce more memory allocation in async paths where sync completion is possible

* Fix bug causing constant refresh in the case of flag overrides using simplified config

* Slightly change flag override behavior so an unsupported value doesn't prevent other overrides + add tests

* Fix finalizer-related tests

* Update version

CHANGELOG.md

@@ -1,205 +1 @@
-### 7.2.0
-
-- Introduced a new local dictionary override factory method:
-  ```csharp
-  FlagOverrides LocalDictionary(IDictionary<string, object> dictionary, bool watchChanges, OverrideBehaviour overrideBehaviour)
-  ``` 
-  Where the `watchChanges` parameter indicates whether the SDK should rebuild the overrides upon each read to keep track of the source dictionary's changes.
-- Fix config fetcher-related error logging to include exception in the log if any.
-
-### 7.1.0
-
-- Add new evaluation methods `GetAllValueDetails`/`GetAllValueDetailsAsync`.
-- Fix logging in `ConfigServiceBase.SetOnline`.
-- Correct behavior of `GetAllXXX` methods so `FlagEvaluated` event is also raised in case of error.
-- Correct reporting of "Config JSON is not present" errors and log them with error level also in the case of `GetAllXXX` methods.
-- Change implementation of `HttpConfigFetcher.FetchAsync` to execute only one fetch operation at a time.
-- Make `ProjectConfig` equality comparison consistent with other SDKs (treats `ProjectConfig` instances with the same ETag equal regardless of actual content).
-- Make HTTP response handling consistent with other SDKs.
-- Make `HttpConfigFetcher`-related error message consistent with other SDKs.
-
-### 7.0.0
-- Deprecate `ConfigCatClient` constructors in favor of the new static factory method `Get`,
-  which provides single client instances per SDK key.
-- Add convenience method `DisposeAll` for disposing all open clients at once.
-- Implement default user feature.
-- Implement offline mode feature.
-- Improve LazyLoad and AutoPoll refresh logic by taking the cache timestamp into account
-  to fetch the config only if cached config is unavailable or stale.
-- Add new evaluation methods `GetValueDetail`/`GetValueDetailsAsync`,
-  which provide more detailed information about the evaluation result.
-- Add hooks (events), which provide notifications of the client's actions.  
-- Additional minor code quality and performance improvements.
-- Update samples to .NET 6.
-
-### 6.5.3
-- Use logger wrapper everywhere internally. #39
-- Improved evaluation logging. #38
-
-### 6.5.2
-- Consolidate percentage rule evaluation logs.
-
-### 6.5.1
-- Add net461 to the target frameworks list to force the usage of `System.Text.Json` rather than `Newtonsoft.Json`.
-
-### 6.5.0
-- Replace `FileSystemWatcher` with file polling in local file override data source.
-
-### 6.4.12
-- Fix various local file override data source issues.
-
-### 6.4.9
-- Move the PollingMode option to public scope.
-
-### 6.4.8
-- Readd `System.Text.RegularExpressions` version `4.3.1` due to SNYK security report.
-
-### 6.4.7
-- Remove unused `System.Text.RegularExpressions` dependency.
-
-### 6.4.6
-- Fix the wait time calculation in auto-polling mode.
-
-### 6.4.3
-- Fix README links displayed on the NuGet package page.
-
-### 6.4.0
-- **Introduced a new configuration API replacing the builder pattern**:
-
-  ```cs
-  ConfigCatClientBuilder
-      .Initialize(SDKKEY)
-      .WithLogger(consoleLogger)
-      .WithAutoPoll()
-          .WithMaxInitWaitTimeSeconds(5)
-          .WithPollIntervalSeconds(60)
-      .Create();
-  ```
-
-  Will look like this:
-  ```cs
-  new ConfigCatClient(options =>
-  {
-      options.SdkKey = SDKKEY;
-      options.PollingMode = PollingModes.AutoPoll(TimeSpan.FromSeconds(60), TimeSpan.FromSeconds(5));
-      options.Logger = consoleLogger;
-  });
-  ```
-
-  The old API is still available it's just marked with the `[Obsolete]` attribute.
-
-- **`GetAllValues()` and `GetAllValuesAsync()`**:  
-  These methods are now evaluating all feature flags and settings into an `IDictionary<string, object>`.
-
-- **FlagOverrides**:  
-  It's now possible to feed the SDK with local feature flag and setting values. 
-  - **Dictionary**
-    ```cs
-    var dict = new Dictionary<string, object>
-    {
-        {"enabledFeature", true},
-        {"intSetting", 5},
-    };
-
-    using var client = new ConfigCatClient(options =>
-    {
-        options.SdkKey = "localhost";
-        options.FlagOverrides = FlagOverrides.LocalDictionary(dict, 
-            OverrideBehaviour.LocalOnly);
-    });
-    ```
-  - **File**
-    ```cs
-    using var client = new ConfigCatClient(options =>
-    {
-        options.SdkKey = "localhost";
-        options.FlagOverrides = FlagOverrides.LocalFile("path/to/file", 
-            autoReload: false, 
-            overrideBehaviour: OverrideBehaviour.LocalOnly);
-    });
-    ```
-  Three behaviours available: `LocalOnly`, `LocalOverRemote`, and `RemoteOverLocal`.
-  With `LocalOnly` the SDK switches into a complete offline state, and only the override values are served.
-  `LocalOverRemote` and `RemoteOverLocal` merge the local and remote feature flag values respecting one or another in case of key duplications.
-
-- **Changes in JSON handling**:  
-  In respect of [#30](https://github.com/configcat/.net-sdk/issues/30) `System.Text.Json` is favored over `Newtonsoft.Json` in frameworks newer than `net45`. `System.Text.Json` is not available for `net45` so that target remains using `Newtonsoft.Json`.
-
-- **`net5.0` and `net6.0` target frameworks**.
-
-- **HttpTimeout configuration option**.
-
-- **Solution for** [#26](https://github.com/configcat/.net-sdk/issues/26).
-  To prevent possible deadlocks the following changes were applied:
-  - Created a synchronous extension for the existing fully async `IConfigCache`. In the future we will replace that interface with the new one (`IConfigCatCache`) that has now the sync API and inherits the async API from `IConfigCache`.  `IConfigCache` was marked with `[Obsolete]` to maintain backward compatibility. `InMemoryConfigCache` now implements both sync and async APIs through `IConfigCatCache`.
-  - Extended the config services (`AutoPoll`, `LazyLoad`, `ManualPoll`) with synchronous branches that are using the new cache's sync / async methods in respect of sync and async customer calls.
-  - Extended the `HttpConfigFetcher` with a synchronous `Fetch` that uses the `HttpClient`'s `Send()` method where it's available (`net5.0` and above). Below `net5.0` the synchronous path falls back to a functionality that queues the HTTP request to a thread pool thread and waits for its completion. This solution prevents deadlocks however, it puts more load on the thread pool.
-
-- **CI Changes**:
-  - Introduced new [GitHub actions for Linux and macOS builds](https://github.com/configcat/.net-sdk/actions/workflows/linux-macOS-CI.yml). 
-  - The [sonarcloud analysis](https://github.com/configcat/.net-sdk/actions/workflows/sonar-analysis.yml) is moved to a separate Action from the appveyor task. 
-  - Removed codecov completely, it will be replaced by the coverage data from sonarcloud.
-
-### 6.2.1
-- Reducing the number of json deserializations between `GetValue` calls.
-### 6.1.20
-- Bugfix: The SDK's json serialization behavior is not depending on the `JsonConvert.DefaultSettings` anymore.
-### 6.1.0
-- Bugfix ([#17](https://github.com/configcat/.net-sdk/issues/17))
-### 6.0.0
-- Addressing global data handling and processing trends via Data Governance feature. Customers can control the geographic location where their config JSONs get published to. [See the docs](https://configcat.com/docs/advanced/data-governance/).
-We are introducing a new DataGovernance initialization parameter. Set this parameter to be in sync with the Data Governance preference on the [Dashboard](https://app.configcat.com/organization/data-governance).
-       
-#### Breaking changes:
-### 7.1.0
-- [API] Remove `BeforeClientDispose` hook
-### 7.0.0
-- [API] Add new methods to the `IConfigCatClient` interface.
-- [API] Change `ProjectConfig` to reference type with value equality (record).
-- [Behavior] Slightly changes the behavior of ProjectConfig.TimeStamp (only updated when communication with the CDN servers succeeds, regardless of the returned status code.)
-### 6.0.0
-- Custom cache implementations should implement the new cache interface using key parameter in the get/set methods.
-### 5.3.0
-- VariationID, bugfix ([#11](https://github.com/configcat/.net-sdk/issues/11))
-### 5.2.0
-- Bugfix (config fetch, caching)
-### 5.1.0
-- Remove semver nuget packages
-### 5.0.0
-- Breaking change: Renamed `API Key` to `SDK Key`.
-### 4.0.0
-- Supporting sensitive text comparators.
-### 3.2.0
-- Minor fix in info level logging
-### 3.1.0
-- Added new semantic version tests
-### 3.0.0
-- Support new types (number, semver), detailed log entries, compressed http communication
-### 2.5.0
-- Support custom HttpClientHandler
-### 2.4.0
-- Add GetAllKeys() function
-### 2.3.0
-- BaseUrl override oppurtunity
-- IConfigCache override oppurtunity
-### 2.3.0
-- BaseUrl override oppurtunity
-- IConfigCache override oppurtunity
-### 2.2.1
-- Bugfix (logger level)
-### 2.2.0
-- Namespace unification
-### 2.1.0
-- Rollout handling v2
-### 2.0.1
-- Bugfix
-### 2.0.0
-- Implement rollout feature
-### 1.0.7
-- Implement LazyLoad, AutoPoll, ManualPoll feature
-### 1.0.6
-- Finalize logging
-### 1.0.5
-- Implement tracing, add clear cache ability to client
-### 1.0.4
-- Initial release
+Please check the [Github Releases](https://github.com/configcat/.net-sdk/releases) page for the changelog of the ConfigCat SDK for .NET.

DEPLOY.md

@@ -1,13 +1,12 @@
 # Steps to Deploy
 1. Run tests
 2. Set version in `appveyor.yml` (e.g: from `build_version: 6.5.0` to `build_version: 6.5.1`)
-3. Update release notes in CHANGELOG.md
-4. Open a PR
-5. When the PR is merged to master, start a deploy to NuGet.org
+3. Open a PR
+4. When the PR is merged to master, start a deploy to NuGet.org
 
     Create a new deployment on  https://ci.appveyor.com/project/configcat/net-sdk/deployments
-6. Make sure new package is available via Nuget.org: https://www.nuget.org/packages/ConfigCat.Client
-7. Update and test sample apps with the new SDK version.
+5. Make sure new package is available via Nuget.org: https://www.nuget.org/packages/ConfigCat.Client
+6. Update and test sample apps with the new SDK version.
 
     *Usually it takes a few minutes to propagate.*
-8. Add release notes: https://github.com/configcat/.net-sdk/releases
+7. Add release notes: https://github.com/configcat/.net-sdk/releases

appveyor.yml

@@ -1,5 +1,5 @@
 environment:
-  build_version: 7.2.0
+  build_version: 8.0.0
 version: $(build_version)-{build}
 image: Visual Studio 2022
 configuration: Release
@@ -11,10 +11,10 @@ dotnet_csproj:
   patch: true
   file: '**\*.csproj'
   version: $(build_version)
-  package_version: $(build_version)
+  package_version: $(build_version)-preview1
   assembly_version: $(build_version)
   file_version: $(build_version)
-  informational_version: $(build_version)
+  informational_version: $(build_version)-preview1
 install:
 - cmd: dotnet tool install -g InheritDocTool
 build_script: 
@@ -24,9 +24,10 @@ build_script:
 after_build:
 - cmd: echo __PACK__
 - inheritdoc -o
-- dotnet pack -c %configuration% /p:IncludeSymbols=true /p:PackageOutputPath=..\..\artifacts /p:SymbolPackageFormat=snupkg src\ConfigCatClient\ConfigCatClient.csproj
+- dotnet pack -c %configuration% /p:PackageOutputPath=..\..\artifacts /p:ContinuousIntegrationBuild=true src\ConfigCatClient\ConfigCatClient.csproj
 test_script:
 - dotnet test src\ConfigCat.Client.Tests\ConfigCat.Client.Tests.csproj -f net45 -c %configuration% --no-build
+- dotnet test src\ConfigCat.Client.Tests\ConfigCat.Client.Tests.csproj -f net461 -c %configuration% --no-build
 - dotnet test src\ConfigCat.Client.Tests\ConfigCat.Client.Tests.csproj -f netcoreapp3.1 -c %configuration% --no-build
 - dotnet test src\ConfigCat.Client.Tests\ConfigCat.Client.Tests.csproj -f net5.0 -c %configuration% --no-build
 - dotnet test src\ConfigCat.Client.Tests\ConfigCat.Client.Tests.csproj -f net6.0 -c %configuration% --no-build

samples/ASP.NETCore/WebApplication/Adapters/ConfigCatToMSLoggerAdapter.cs

@@ -15,7 +15,11 @@ public ConfigCatToMSLoggerAdapter(ILogger<ConfigCat.Client.ConfigCatClient> logg
     }
 
     // Allow all log levels here and let MS logger do log level filtering (see appsettings.json)
-    public ConfigCat.Client.LogLevel LogLevel { get; set; } = ConfigCat.Client.LogLevel.Debug;
+    public ConfigCat.Client.LogLevel LogLevel
+    {
+        get => ConfigCat.Client.LogLevel.Debug;
+        set { }
+    }
 
     public void Log(ConfigCat.Client.LogLevel level, ConfigCat.Client.LogEventId eventId, ref ConfigCat.Client.FormattableLogMessage message, Exception? exception = null)
     {

samples/FileLoggerSample.cs

@@ -9,10 +9,17 @@ class Program
     {
         class MyFileLogger : IConfigCatLogger
         {
-            private readonly string filePath;
             private static readonly object SyncObj = new object();
 
-            public LogLevel LogLevel { get; set; }
+            private readonly string filePath;
+
+            private volatile LogLevel logLevel;
+
+            public LogLevel LogLevel
+            {
+                get => this.logLevel;
+                set => this.logLevel = value;
+            }
 
             public MyFileLogger(string filePath, LogLevel logLevel)
             {

src/ConfigCat.Client.Tests/BasicConfigCatClientIntegrationTests.cs

@@ -1,14 +1,11 @@
 using System;
-using System.CodeDom;
-using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Linq;
 using System.Net.Http;
 using System.Threading;
 using System.Threading.Tasks;
 using ConfigCat.Client.Configuration;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
-using Moq;
 
 namespace ConfigCat.Client.Tests;
 

src/ConfigCat.Client.Tests/BasicConfigEvaluatorTests.cs

@@ -1,11 +1,8 @@
 using System;
 using System.Collections.Generic;
-using System.Linq;
 using System.Reflection;
-using System.Runtime.CompilerServices;
 using ConfigCat.Client.Evaluation;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
-using Moq;
 
 namespace ConfigCat.Client.Tests;
 

src/ConfigCat.Client.Tests/ConfigCacheTests.cs

@@ -157,14 +157,14 @@ public async Task ConfigCache_Works(bool isExternal, bool isAsync)
 
         Task<ProjectConfig> ReadCacheAsync()
         {
-            return isAsync ? configCache.GetAsync(cacheKey) : Task.FromResult(configCache.Get(cacheKey));
+            return isAsync ? configCache.GetAsync(cacheKey).AsTask() : Task.FromResult(configCache.Get(cacheKey));
         }
 
         Task WriteCacheAsync(ProjectConfig config)
         {
             if (isAsync)
             {
-                return configCache.SetAsync(cacheKey, config);
+                return configCache.SetAsync(cacheKey, config).AsTask();
             }
             else
             {

src/ConfigCat.Client.Tests/ConfigCatClientCacheTests.cs

@@ -1,7 +1,5 @@
 using System;
-using System.Linq;
 using System.Runtime.CompilerServices;
-using System.Runtime.InteropServices;
 using ConfigCat.Client.Configuration;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 

src/ConfigCat.Client.Tests/ConfigCatClientTests.cs

@@ -1257,6 +1257,9 @@ public void DisposeAll_CachedInstancesRemoved()
 
         instanceCount1 = ConfigCatClient.Instances.GetAliveCount();
 
+        GC.KeepAlive(client1);
+        GC.KeepAlive(client2);
+
         ConfigCatClient.DisposeAll();
 
         var instanceCount2 = ConfigCatClient.Instances.GetAliveCount();
@@ -1284,6 +1287,9 @@ static void CreateClients(out int instanceCount)
             var client2 = ConfigCatClient.Get("test2", options => options.PollingMode = PollingModes.ManualPoll);
 
             instanceCount = ConfigCatClient.Instances.GetAliveCount();
+
+            GC.KeepAlive(client1);
+            GC.KeepAlive(client2);
         }
 
         // Act
@@ -1801,14 +1807,14 @@ protected override void Dispose(bool disposing)
             base.Dispose(disposing);
         }
 
-        public Task<ProjectConfig> GetConfigAsync(CancellationToken cancellationToken = default)
+        public ValueTask<ProjectConfig> GetConfigAsync(CancellationToken cancellationToken = default)
         {
-            return Task.FromResult(ProjectConfig.Empty);
+            return new ValueTask<ProjectConfig>(ProjectConfig.Empty);
         }
 
-        public override Task<RefreshResult> RefreshConfigAsync(CancellationToken cancellationToken = default)
+        public override ValueTask<RefreshResult> RefreshConfigAsync(CancellationToken cancellationToken = default)
         {
-            return Task.FromResult(RefreshConfig());
+            return new ValueTask<RefreshResult>(RefreshConfig());
         }
 
         public ProjectConfig GetConfig()