(chocolatey#1935) Add User Agent test to ensure NuGet version is used

This both ensures that the user agent is set, when NuGet sources are configured
and that it uses the upstream version of NuGet that the NuGet assembles are
based on. This same version is used in other areas as well, like minClientVersion,
so it applies to multiple areas.

src/chocolatey.tests.integration/scenarios/PackScenarios.cs

@@ -499,24 +499,24 @@ public void Should_throw_exception_on_icon_element()
             }
         }
 
-        public class when_packing_with_min_client_version : ScenariosBase
+        public class When_packing_with_min_client_version : ScenariosBase
         {
             protected override string ExpectedNuspecVersion => "0.1.0";
             protected override string ExpectedSubDirectory => "PackageOutput";
 
             // This high version is to ensure that pack does not throw, even if the min client version is well
             // above both the Chocolatey and NuGet assembly versions.
-            private string MinClientVersion = "100.0.0";
+            private string _MinClientVersion = "100.0.0";
 
             public override void Because()
             {
-                MockLogger.reset();
-                Service.pack_run(Configuration);
+                MockLogger.Reset();
+                Service.Pack(Configuration);
             }
 
             protected override string GetNuspecContent()
             {
-                return NuspecContentWithFormatableMinClientVersion.format_with(MinClientVersion);
+                return NuspecContentWithFormatableMinClientVersion.FormatWith(_MinClientVersion);
             }
         }
 

src/chocolatey.tests/infrastructure.app/nuget/NugetCommonSpecs.cs

@@ -19,6 +19,7 @@ namespace chocolatey.tests.infrastructure.app.nuget
     using System;
     using System.Collections.Generic;
     using System.Linq;
+    using chocolatey.infrastructure.app;
     using chocolatey.infrastructure.app.configuration;
     using chocolatey.infrastructure.app.nuget;
     using chocolatey.infrastructure.filesystem;
@@ -161,6 +162,22 @@ public void Should_parse_unc_source()
                 packageRepositories.First().PackageSource.IsLocal.ShouldBeTrue();
                 packageRepositories.First().PackageSource.SourceUri.IsUnc.ShouldBeTrue();
             }
+
+            [Fact]
+            public void Should_set_user_agent_string()
+            {
+                Context();
+                var source = "https://community.chocolatey.org/api/v2/";
+                configuration.Sources = source;
+                configuration.Information.ChocolateyProductVersion = "vNext";
+
+                because();
+
+                // Change this when the NuGet version is updated.
+                string nugetClientVersion = "6.4.1";
+                string expectedUserAgentString = "{0}/{1} via NuGet Client/{2}".FormatWith(ApplicationParameters.UserAgent, configuration.Information.ChocolateyProductVersion, nugetClientVersion);
+                UserAgent.UserAgentString.ShouldStartWith(expectedUserAgentString);
+            }
         }
     }
 }