add test with lambdacontext, refactor

Author: hjgraca

libraries/tests/AWS.Lambda.Powertools.Metrics.Tests/AWS.Lambda.Powertools.Metrics.Tests.csproj

@@ -10,6 +10,8 @@
     <ItemGroup>
         <!--   Package versions are Centrally managed in Directory.Packages.props file  -->
         <!--   More info https://learn.microsoft.com/en-us/nuget/consume-packages/central-package-management   -->
+        <PackageReference Include="Amazon.Lambda.Core" />
+        <PackageReference Include="Amazon.Lambda.TestUtilities" />
         <PackageReference Include="Microsoft.NET.Test.Sdk" />
         <PackageReference Include="xunit" />
         <PackageReference Include="xunit.runner.visualstudio">

libraries/tests/AWS.Lambda.Powertools.Metrics.Tests/EMFValidationTests.cs

@@ -341,18 +341,7 @@ private List<int> AllIndexesOf(string str, string value)
                 indexes.Add(index);
             }
         }
-
-        private class CustomConsoleWriter : StringWriter
-        {
-            public readonly List<string> OutputValues = new();
-
-            public override void WriteLine(string value)
-            {
-                OutputValues.Add(value);
-                base.WriteLine(value);
-            }
-        }
-
+        
         #endregion
 
 

libraries/tests/AWS.Lambda.Powertools.Metrics.Tests/Handlers/FunctionHandler.cs

@@ -19,6 +19,8 @@
 using System.Globalization;
 using System.Linq;
 using System.Threading.Tasks;
+using Amazon.Lambda.Core;
+using Amazon.Lambda.TestUtilities;
 
 namespace AWS.Lambda.Powertools.Metrics.Tests.Handlers;
 
@@ -159,4 +161,16 @@ await Parallel.ForEachAsync(Enumerable.Range(0, Environment.ProcessorCount * 2),
 
         return input.ToUpper(CultureInfo.InvariantCulture);
     }
+
+    [Metrics(Namespace = "ns", Service = "svc", CaptureColdStart = true)]
+    public void HandleWithLambdaContext(ILambdaContext context)
+    {
+        
+    }
+
+    [Metrics(Namespace = "ns", Service = "svc")]
+    public void HandleWithLambdaContextAndMetrics(TestLambdaContext context)
+    {
+        Metrics.AddMetric("MyMetric", 1);
+    }
 }

libraries/tests/AWS.Lambda.Powertools.Metrics.Tests/Handlers/FunctionHandlerTests.cs

@@ -15,22 +15,33 @@
 
 using System;
 using System.Threading.Tasks;
+using Amazon.Lambda.TestUtilities;
+using AWS.Lambda.Powertools.Common;
 using Xunit;
 
 namespace AWS.Lambda.Powertools.Metrics.Tests.Handlers;
 
 [Collection("Sequential")]
 public class FunctionHandlerTests : IDisposable
 {
+    private readonly FunctionHandler _handler;
+    private readonly CustomConsoleWriter _consoleOut;
+    
+    public FunctionHandlerTests()
+    {
+        _handler = new FunctionHandler();
+        _consoleOut = new CustomConsoleWriter();
+        SystemWrapper.Instance.SetOut(_consoleOut);
+    }
+    
     [Fact]
     public async Task When_Metrics_Add_Metadata_Same_Key_Should_Ignore_Metadata()
     {
         // Arrange
-        Metrics.ResetForTest();
-        var handler = new FunctionHandler();
+        
 
         // Act
-        var exception = await Record.ExceptionAsync( () => handler.HandleSameKey("whatever"));
+        var exception = await Record.ExceptionAsync( () => _handler.HandleSameKey("whatever"));
 
         // Assert
         Assert.Null(exception);
@@ -39,32 +50,48 @@ public async Task When_Metrics_Add_Metadata_Same_Key_Should_Ignore_Metadata()
     [Fact]
     public async Task When_Metrics_Add_Metadata_Second_Invocation_Should_Not_Throw_Exception()
     {
-        // Arrange
-        Metrics.ResetForTest();
-        var handler = new FunctionHandler();
-
         // Act
-        var exception = await Record.ExceptionAsync( () => handler.HandleTestSecondCall("whatever"));
+        var exception = await Record.ExceptionAsync( () => _handler.HandleTestSecondCall("whatever"));
         Assert.Null(exception);
 
-        exception = await Record.ExceptionAsync( () => handler.HandleTestSecondCall("whatever"));
+        exception = await Record.ExceptionAsync( () => _handler.HandleTestSecondCall("whatever"));
         Assert.Null(exception);
     }
 
     [Fact]
     public async Task When_Metrics_Add_Metadata_FromMultipleThread_Should_Not_Throw_Exception()
     {
-        // Arrange
-        Metrics.ResetForTest();
-        var handler = new FunctionHandler();
-
         // Act
-        var exception = await Record.ExceptionAsync(() => handler.HandleMultipleThreads("whatever"));
+        var exception = await Record.ExceptionAsync(() => _handler.HandleMultipleThreads("whatever"));
         Assert.Null(exception);
     }
+    
+    [Fact]
+    public void When_LambdaContext_Should_Add_FunctioName_Dimension_CaptureColdStart()
+    {
+        // Arrange
+        var context = new TestLambdaContext
+        {
+            FunctionName = "My Function with context"
+        };
+        
+        // Act
+        _handler.HandleWithLambdaContext(context);
+        var metricsOutput = _consoleOut.ToString();
+        
+        // Assert
+        Assert.Contains(
+            "\"FunctionName\":\"My Function with context\"",
+            metricsOutput);
+        
+        Assert.Contains(
+            "\"Metrics\":[{\"Name\":\"ColdStart\",\"Unit\":\"Count\"}],\"Dimensions\":[[\"FunctionName\"],[\"Service\"]]}]}",
+            metricsOutput);
+    }
 
     public void Dispose()
     {
+        Metrics.ResetForTest();
         MetricsAspect.ResetForTest();
     }
 }

libraries/tests/AWS.Lambda.Powertools.Metrics.Tests/Utils.cs

@@ -0,0 +1,30 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file is distributed
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ * express or implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ */
+
+using System.Collections.Generic;
+using System.IO;
+
+namespace AWS.Lambda.Powertools.Metrics.Tests;
+
+public class CustomConsoleWriter : StringWriter
+{
+    public readonly List<string> OutputValues = new();
+
+    public override void WriteLine(string value)
+    {
+        OutputValues.Add(value);
+        base.WriteLine(value);
+    }
+}