Added unit tests and restructured folders (#1)

1. Moved projects to dedicated projects' folder.
2. Updated gitignore
3. Added unit tests

.gitignore

@@ -1,9 +1,43 @@
+*.swp
+*.*~
+project.lock.json
+.DS_Store
+*.pyc
+nupkg/
+
+# Visual Studio Code
+.vscode/
+
+# Rider
+.idea/
+
+# Visual Studio
+.vs/
+
+# Fleet
+.fleet/
+
+# Code Rush
+.cr/
+
+# User-specific files
+*.suo
 *.user
-*.opencover.xml
-*.orig
-*.nupkg
-*.snupkg
-.idea
-bin
-obj
-BenchmarkDotNet.Artifacts
+*.userosscache
+*.sln.docstates
+
+# Build results
+[Dd]ebug/
+[Dd]ebugPublic/
+[Rr]elease/
+[Rr]eleases/
+x64/
+x86/
+build/
+bld/
+[Bb]in/
+[Oo]bj/
+[Oo]ut/
+msbuild.log
+msbuild.err
+msbuild.wrn

Prometheus.Client.MetricPusher.HostedService.sln

@@ -1,18 +1,31 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Prometheus.Client.MetricPusher.HostedService", "src\Prometheus.Client.MetricPusher.HostedService.csproj", "{C77EB3BB-08D7-4B18-9833-6D5486AA42C8}"
+# Visual Studio Version 17
+VisualStudioVersion = 17.7.34003.232
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Prometheus.Client.MetricPusher.HostedService", "src\Prometheus.Client.MetricPusher.HostedService\Prometheus.Client.MetricPusher.HostedService.csproj", "{CD73BF99-211A-496F-983B-A55A22DE4FEE}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Prometheus.Client.MetricPusher.HostedService.Tests", "src\Prometheus.Client.MetricPusher.HostedService.Tests\Prometheus.Client.MetricPusher.HostedService.Tests.csproj", "{33C6BDD1-6FAF-4EBC-83DE-B10895F69848}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
 		Release|Any CPU = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(ProjectConfigurationPlatforms) = postSolution
-		{C77EB3BB-08D7-4B18-9833-6D5486AA42C8}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{C77EB3BB-08D7-4B18-9833-6D5486AA42C8}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{C77EB3BB-08D7-4B18-9833-6D5486AA42C8}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{C77EB3BB-08D7-4B18-9833-6D5486AA42C8}.Release|Any CPU.Build.0 = Release|Any CPU
+		{CD73BF99-211A-496F-983B-A55A22DE4FEE}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{CD73BF99-211A-496F-983B-A55A22DE4FEE}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{CD73BF99-211A-496F-983B-A55A22DE4FEE}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{CD73BF99-211A-496F-983B-A55A22DE4FEE}.Release|Any CPU.Build.0 = Release|Any CPU
+		{33C6BDD1-6FAF-4EBC-83DE-B10895F69848}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{33C6BDD1-6FAF-4EBC-83DE-B10895F69848}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{33C6BDD1-6FAF-4EBC-83DE-B10895F69848}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{33C6BDD1-6FAF-4EBC-83DE-B10895F69848}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
 	EndGlobalSection
-	GlobalSection(NestedProjects) = preSolution
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {2A144989-FB17-400D-A3E8-78C7534AF12F}
 	EndGlobalSection
 EndGlobal

src/Prometheus.Client.MetricPusher.HostedService.Tests/GlobalUsings.cs

@@ -0,0 +1,2 @@
+global using Xunit;
+global using FluentAssertions;

src/Prometheus.Client.MetricPusher.HostedService.Tests/MetricPusherServiceTests.cs

@@ -0,0 +1,26 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Moq;
+
+namespace Prometheus.Client.MetricPusher.HostedService.Tests
+{
+    public class MetricPusherServiceTests
+    {
+        [Fact]
+        public async Task WithGivenInterval_PushMetricPeriodically()
+        {
+            var metricPusherMock = new Moq.Mock<IMetricPusher>();
+            var metricPusherService = new MetricPusherService(metricPusherMock.Object, TimeSpan.FromSeconds(1));
+            var canellationToken = It.IsAny<CancellationToken>();
+
+            await metricPusherService.StartAsync(canellationToken);
+            await Task.Delay(TimeSpan.FromSeconds(1));
+            await metricPusherService.StopAsync(canellationToken);
+
+            metricPusherMock.Verify(o => o.PushAsync(), Moq.Times.AtLeast(2));
+        }
+    }
+}

src/Prometheus.Client.MetricPusher.HostedService.Tests/Prometheus.Client.MetricPusher.HostedService.Tests.csproj

@@ -0,0 +1,32 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net6.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+
+    <IsPackable>false</IsPackable>
+    <IsTestProject>true</IsTestProject>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="CleanMoq" Version="1.0.0" />
+    <PackageReference Include="FluentAssertions" Version="6.11.0" />
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="7.0.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.5.0" />
+    <PackageReference Include="xunit" Version="2.4.2" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.5">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="coverlet.collector" Version="3.2.0">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\Prometheus.Client.MetricPusher.HostedService\Prometheus.Client.MetricPusher.HostedService.csproj" />
+  </ItemGroup>
+
+</Project>

src/Prometheus.Client.MetricPusher.HostedService.Tests/ServiceCollecttionExtensionsTests.cs

@@ -0,0 +1,42 @@
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+
+namespace Prometheus.Client.MetricPusher.HostedService.Tests
+{
+    public class ServiceCollecttionExtensionsTests
+    {
+        [Fact]
+        public void AddMetricPusherService_WithNullMetricPusher_ThrowsArgumentNullException()
+        {
+            IServiceCollection servicesCollection = Moq.Mock.Of<IServiceCollection>();
+
+            Action act = () => ServiceCollectionExtensions.AddMetricPusherService(servicesCollection, null, TimeSpan.FromSeconds(1));
+
+            act.Should().Throw<ArgumentNullException>();
+        }
+
+        [Fact]
+        public void AddMetricPusherService_WithZeroTimeInterval_ThrowsArgumentOutOfRangeException()
+        {
+            IServiceCollection servicesCollection = Moq.Mock.Of<IServiceCollection>();
+            IMetricPusher metricPusher = Moq.Mock.Of<IMetricPusher>();
+
+            Action act = () => ServiceCollectionExtensions.AddMetricPusherService(servicesCollection, metricPusher, TimeSpan.Zero);
+
+            act.Should().Throw<ArgumentOutOfRangeException>();
+        }
+
+        [Fact]
+        public void AddMetricPusherService_WithValidParameterValues_AddsMetricPusherServiceInServiceCollection()
+        {
+            IServiceCollection servicesCollection = new ServiceCollection();
+            IMetricPusher metricPusher = Moq.Mock.Of<IMetricPusher>();
+
+            ServiceCollectionExtensions.AddMetricPusherService(servicesCollection, metricPusher, TimeSpan.FromSeconds(1));
+            var provider = servicesCollection.BuildServiceProvider();
+            var service = provider.GetRequiredService<IHostedService>();
+
+            service.Should().BeOfType<MetricPusherService>();
+        }
+    }
+}