Merge pull request #7 from prom-client-net/feat/default-interval

feat: add default interval

Author: phnx47

.ruleset

@@ -130,6 +130,7 @@
     <Rule Id="SA1400" Action="None" />
     <Rule Id="SA1401" Action="None" />
     <Rule Id="SA1119" Action="None" />
+    <Rule Id="SA1407" Action="None" />
     <Rule Id="SA1410" Action="None" />
     <Rule Id="SA1411" Action="None" />
     <Rule Id="SA1404" Action="None" />

README.md

@@ -29,7 +29,7 @@ var metricPusher = new MetricPusher(new MetricPusherOptions
 ```
 
 ```c#
-services.AddMetricPusherService(metricPusher, TimeSpan.FromSeconds(1));
+services.AddMetricPusherService(metricPusher);
 ```
 
 ## Contribute

src/Defaults.cs

@@ -0,0 +1,8 @@
+using System;
+
+namespace Prometheus.Client.MetricPusher.HostedService;
+
+internal static class Defaults
+{
+    internal static TimeSpan Interval = TimeSpan.FromMilliseconds(1000);
+}

src/MetricPusherService.cs

@@ -10,39 +10,45 @@ public class MetricPusherService : BackgroundService
     private readonly IMetricPusher _pusher;
     private readonly TimeSpan _interval;
 
+    public MetricPusherService(IMetricPusher pusher)
+        : this(pusher, Defaults.Interval)
+    {
+    }
+
     public MetricPusherService(IMetricPusher pusher, TimeSpan interval)
     {
-        _interval = interval;
         _pusher = pusher;
+        _interval = interval;
     }
 
     protected override async Task ExecuteAsync(CancellationToken stoppingToken)
     {
-        async Task DoPushAsync()
+        while (!stoppingToken.IsCancellationRequested)
         {
+            await DoPushAsync();
             try
             {
-                await _pusher.PushAsync();
+                await Task.Delay(_interval, stoppingToken);
             }
-            catch (Exception)
+            catch (TaskCanceledException)
             {
-                // TODO: report error to DiagnosticSource?
             }
         }
 
-        while (!stoppingToken.IsCancellationRequested)
+        // Push the very last metric values before exit
+        await DoPushAsync();
+        return;
+
+        async Task DoPushAsync()
         {
-            await DoPushAsync();
             try
             {
-                await Task.Delay(_interval, stoppingToken);
+                await _pusher.PushAsync();
             }
-            catch (TaskCanceledException)
+            catch (Exception)
             {
+                // TODO: report error to DiagnosticSource?
             }
         }
-
-        // Push the very last metric values before exit
-        await DoPushAsync();
     }
 }

src/Prometheus.Client.MetricPusher.HostedService.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <TargetFrameworks>netstandard2.1;net6.0;net7.0</TargetFrameworks>
-    <VersionPrefix>0.1.0</VersionPrefix>
+    <VersionPrefix>0.2.0</VersionPrefix>
     <Description>Prometheus.Client.MetricPusher as HostedService</Description>
     <RepositoryUrl>https://github.com/prom-client-net/prom-client-metricpusher-hostedservice</RepositoryUrl>
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>

src/ServiceCollectionExtensions.cs

@@ -6,6 +6,11 @@ namespace Prometheus.Client.MetricPusher.HostedService;
 
 public static class ServiceCollectionExtensions
 {
+    public static IServiceCollection AddMetricPusherService(this IServiceCollection services, IMetricPusher pusher)
+    {
+        return AddMetricPusherService(services, pusher, Defaults.Interval);
+    }
+
     public static IServiceCollection AddMetricPusherService(this IServiceCollection services, IMetricPusher pusher, TimeSpan interval)
     {
         if (pusher == null)

tests/MetricPusherServiceTests.cs

@@ -1,22 +1,45 @@
 using System.Threading;
 using System.Threading.Tasks;
 
-namespace Prometheus.Client.MetricPusher.HostedService.Tests
+namespace Prometheus.Client.MetricPusher.HostedService.Tests;
+
+public class MetricPusherServiceTests
 {
-    public class MetricPusherServiceTests
+    [Fact]
+    public async Task WithDefaultInterval_PushMetricPeriodically()
+    {
+        var metricPusherMock = Substitute.For<IMetricPusher>();
+        var metricPusherService = new MetricPusherService(metricPusherMock);
+        var canellationToken = Arg.Any<CancellationToken>();
+
+        await metricPusherService.StartAsync(canellationToken);
+        await Task.Delay(GetDelay(1), canellationToken);
+        await metricPusherService.StopAsync(canellationToken);
+
+        await metricPusherMock.Received(3).PushAsync();
+    }
+
+    [Theory]
+    [InlineData(1)]
+    [InlineData(2)]
+    [InlineData(3)]
+    [InlineData(5)]
+    public async Task WithGivenInterval_PushMetricPeriodically(int seconds)
+    {
+        var metricPusherMock = Substitute.For<IMetricPusher>();
+        var metricPusherService = new MetricPusherService(metricPusherMock, TimeSpan.FromSeconds(seconds));
+        var canellationToken = Arg.Any<CancellationToken>();
+
+        await metricPusherService.StartAsync(canellationToken);
+        await Task.Delay(GetDelay(seconds), canellationToken);
+        await metricPusherService.StopAsync(canellationToken);
+
+        await metricPusherMock.Received(3).PushAsync();
+    }
+
+    private static TimeSpan GetDelay(int seconds)
     {
-        [Fact]
-        public async Task WithGivenInterval_PushMetricPeriodically()
-        {
-            var metricPusherMock = Substitute.For<IMetricPusher>();
-            var metricPusherService = new MetricPusherService(metricPusherMock, TimeSpan.FromSeconds(1));
-            var canellationToken = Arg.Any<CancellationToken>();
-
-            await metricPusherService.StartAsync(canellationToken);
-            await Task.Delay(TimeSpan.FromSeconds(1), canellationToken);
-            await metricPusherService.StopAsync(canellationToken);
-
-            await metricPusherMock.Received(3).PushAsync();
-        }
+        var milliseconds = seconds * 1000 + 100;
+        return TimeSpan.FromMilliseconds(milliseconds);
     }
 }

tests/ServiceCollecttionExtensionsTests.cs

@@ -1,42 +1,54 @@
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
 
-namespace Prometheus.Client.MetricPusher.HostedService.Tests
+namespace Prometheus.Client.MetricPusher.HostedService.Tests;
+
+public class ServiceCollecttionExtensionsTests
 {
-    public class ServiceCollecttionExtensionsTests
+    [Fact]
+    public void AddMetricPusherService_WithNullMetricPusher_ThrowsArgumentNullException()
+    {
+        var servicesCollection = Substitute.For<IServiceCollection>();
+
+        Action act = () => servicesCollection.AddMetricPusherService(null, TimeSpan.FromSeconds(1));
+
+        act.Should().Throw<ArgumentNullException>();
+    }
+
+    [Fact]
+    public void AddMetricPusherService_WithZeroTimeInterval_ThrowsArgumentOutOfRangeException()
     {
-        [Fact]
-        public void AddMetricPusherService_WithNullMetricPusher_ThrowsArgumentNullException()
-        {
-            var servicesCollection = Substitute.For<IServiceCollection>();
+        var servicesCollection = Substitute.For<IServiceCollection>();
+        var metricPusher = Substitute.For<IMetricPusher>();
 
-            Action act = () => servicesCollection.AddMetricPusherService(null, TimeSpan.FromSeconds(1));
+        Action act = () => servicesCollection.AddMetricPusherService(metricPusher, TimeSpan.Zero);
 
-            act.Should().Throw<ArgumentNullException>();
-        }
+        act.Should().Throw<ArgumentOutOfRangeException>();
+    }
 
-        [Fact]
-        public void AddMetricPusherService_WithZeroTimeInterval_ThrowsArgumentOutOfRangeException()
-        {
-            var servicesCollection = Substitute.For<IServiceCollection>();
-            var metricPusher = Substitute.For<IMetricPusher>();
+    [Fact]
+    public void AddMetricPusherService_WithDefaultInterval_AddsMetricPusherServiceInServiceCollection()
+    {
+        var servicesCollection = new ServiceCollection();
+        var metricPusher = Substitute.For<IMetricPusher>();
 
-            Action act = () => servicesCollection.AddMetricPusherService(metricPusher, TimeSpan.Zero);
+        servicesCollection.AddMetricPusherService(metricPusher);
+        var provider = servicesCollection.BuildServiceProvider();
+        var service = provider.GetRequiredService<IHostedService>();
 
-            act.Should().Throw<ArgumentOutOfRangeException>();
-        }
+        service.Should().BeOfType<MetricPusherService>();
+    }
 
-        [Fact]
-        public void AddMetricPusherService_WithValidParameterValues_AddsMetricPusherServiceInServiceCollection()
-        {
-            var servicesCollection = new ServiceCollection();
-            var metricPusher = Substitute.For<IMetricPusher>();
+    [Fact]
+    public void AddMetricPusherService_WithValidParameterValues_AddsMetricPusherServiceInServiceCollection()
+    {
+        var servicesCollection = new ServiceCollection();
+        var metricPusher = Substitute.For<IMetricPusher>();
 
-            servicesCollection.AddMetricPusherService(metricPusher, TimeSpan.FromSeconds(1));
-            var provider = servicesCollection.BuildServiceProvider();
-            var service = provider.GetRequiredService<IHostedService>();
+        servicesCollection.AddMetricPusherService(metricPusher, TimeSpan.FromSeconds(1));
+        var provider = servicesCollection.BuildServiceProvider();
+        var service = provider.GetRequiredService<IHostedService>();
 
-            service.Should().BeOfType<MetricPusherService>();
-        }
+        service.Should().BeOfType<MetricPusherService>();
     }
 }