[v3] Change manual instrumentation approach to not use reverse duck-t…

…yping (#5214)

* Fix null ref in `GetManagedTracerVersion()`

* Add benchmark for manual instrumentation

* Try alternative ducktyping approach

* Fix OpenTracing helpers

* Revert the changes to benchmark stat types

Seeing as we're not reverse duck-typing any more, we don't need to do this

* Update manual Ci Visibility to not rely on reverse duck-typing

This is made rather irritating by the fact we _can't_ ducktype Test as an ITest. That, coupled with the APIs that connect module + suite + test together means we need to duplicate the interfaces in their entirety.

It seems to work though 🎉

* Revert the snapshots to match the existing public API

* Use instrumentation of DuckType.DuckCast<T> in Datadog.Trace.Manual.csproj

Means we can avoid having to include the whole DuckTyping library inside Datadog.Trace.Manual
The downside is that it's hard to test in unit tests. as everything requires auto instrumentation

* Skip the duck typing tests that won't work and add some others

* Simplify the implementation

Instead of having wrapper ManualScope implementations etc, we can just use duck typing instead directly. This reduces one level of indirection and reduces the allocations

* Redesign approach with CI Visibility

- Use the standard duck typing approach instead of reverse duck typing
- Remove the ManualTest etc
- Move methods that we _can't_ duck type to be extension methods that we instrument

* Update generated code

* Apply suggestions from code review

Co-authored-by: Kevin Gosse <kevin.gosse@datadoghq.com>

* PR feedback

- Fix previous PR feedback suggestions ;)
- Add [Instrumented] to Tracer.ctor
- Fix merge conflict in IntegrationIdExtensions
- Add missing telemetry integration
- Move TracerSettingsPopulateDictionaryIntegration into correct folder, and rename to PopulateDictionaryIntegration
- Add a unit test for SetTag

* Add unit tests for the mapping between tracersettings and public API settings

* PR Feedback - add helper class for serialization of integration settings

* PR feedback - include initial value in OverrideValue<T> helper

* PR feedback - too many braces

* Fix bug introduced

* Use defaults for null test suite

* Fix merge conflict

---------

Co-authored-by: Kevin Gosse <kevin.gosse@datadoghq.com>

tracer/src/Datadog.Trace.Manual/Ci/ITest.cs

@@ -69,27 +69,6 @@ public interface ITest
     /// <param name="traits">Traits dictionary</param>
     void SetTraits(Dictionary<string, List<string>> traits);
 
-    /// <summary>
-    /// Set Test parameters
-    /// </summary>
-    /// <param name="parameters">TestParameters instance</param>
-    void SetParameters(TestParameters parameters);
-
-    /// <summary>
-    /// Set benchmark metadata
-    /// </summary>
-    /// <param name="hostInfo">Host info</param>
-    /// <param name="jobInfo">Job info</param>
-    void SetBenchmarkMetadata(BenchmarkHostInfo hostInfo, BenchmarkJobInfo jobInfo);
-
-    /// <summary>
-    /// Add benchmark data
-    /// </summary>
-    /// <param name="measureType">Measure type</param>
-    /// <param name="info">Measure info</param>
-    /// <param name="statistics">Statistics values</param>
-    void AddBenchmarkData(BenchmarkMeasureType measureType, string info, BenchmarkDiscreteStats statistics);
-
     /// <summary>
     /// Close test
     /// </summary>

tracer/src/Datadog.Trace.Manual/Ci/Stubs/NullTest.cs

@@ -9,13 +9,19 @@
 
 namespace Datadog.Trace.Ci.Stubs;
 
-internal class NullTest(ITestSuite testSuite, string name, DateTimeOffset? startDate) : ITest
+internal class NullTest : ITest
 {
-    public string? Name { get; } = name;
+    public static readonly NullTest Instance = new();
 
-    public DateTimeOffset StartTime { get; } = startDate ?? DateTimeOffset.UtcNow;
+    private NullTest()
+    {
+    }
+
+    public string? Name => "Undefined";
+
+    public DateTimeOffset StartTime => default;
 
-    public ITestSuite Suite { get; } = testSuite;
+    public ITestSuite Suite => NullTestSuite.Instance;
 
     public void SetTag(string key, string? value)
     {
@@ -41,18 +47,6 @@ public void SetTraits(Dictionary<string, List<string>> traits)
     {
     }
 
-    public void SetParameters(TestParameters parameters)
-    {
-    }
-
-    public void SetBenchmarkMetadata(BenchmarkHostInfo hostInfo, BenchmarkJobInfo jobInfo)
-    {
-    }
-
-    public void AddBenchmarkData(BenchmarkMeasureType measureType, string info, BenchmarkDiscreteStats statistics)
-    {
-    }
-
     public void Close(TestStatus status)
     {
     }

tracer/src/Datadog.Trace.Manual/Ci/Stubs/NullTestModule.cs

@@ -5,13 +5,19 @@
 
 namespace Datadog.Trace.Ci.Stubs;
 
-internal class NullTestModule(string name, string? framework, DateTimeOffset? startDate) : ITestModule
+internal class NullTestModule : ITestModule
 {
-    public string Name { get; } = name;
+    public static readonly NullTestModule Instance = new();
 
-    public DateTimeOffset StartTime { get; } = startDate ?? DateTimeOffset.UtcNow;
+    private NullTestModule()
+    {
+    }
+
+    public string Name => "Undefined";
+
+    public DateTimeOffset StartTime => default;
 
-    public string? Framework { get; } = framework;
+    public string? Framework => null;
 
     public void SetTag(string key, string? value)
     {
@@ -41,9 +47,7 @@ public void Close(TimeSpan? duration)
 
     public Task CloseAsync(TimeSpan? duration) => Task.CompletedTask;
 
-    public ITestSuite GetOrCreateSuite(string name)
-        => new NullTestSuite(this, name, null);
+    public ITestSuite GetOrCreateSuite(string name) => NullTestSuite.Instance;
 
-    public ITestSuite GetOrCreateSuite(string name, DateTimeOffset? startDate)
-        => new NullTestSuite(this, name, startDate);
+    public ITestSuite GetOrCreateSuite(string name, DateTimeOffset? startDate) => NullTestSuite.Instance;
 }