feat(commons): preclude empty containers from output (#575)

The PR changes AllureLifecycle to only write a container if it has
at least one fixture of any type.

Author: delatrie

Allure.Net.Commons.Tests/AllureLifeCycleTest.cs

@@ -227,5 +227,48 @@ public void HistoryAndTestCaseIdsAreNotOverwrittenAfterStop()
             Assert.That(lifecycle.Context.CurrentTest.historyId, Is.EqualTo("history-id"));
             Assert.That(lifecycle.Context.CurrentTest.testCaseId, Is.EqualTo("testcase-id"));
         }
+
+        [Test]
+        public void EmptyTestContainerNotWritten()
+        {
+            var writer = new InMemoryResultsWriter();
+            var lifecycle = new AllureLifecycle(_ => writer);
+            lifecycle.StartTestContainer(new() { uuid = "foo" });
+            lifecycle.StopTestContainer();
+
+            lifecycle.WriteTestContainer();
+
+            Assert.That(writer.testContainers, Is.Empty);
+        }
+
+        [Test]
+        public void ContainerWithBeforeFixtureIsWritten()
+        {
+            var writer = new InMemoryResultsWriter();
+            var lifecycle = new AllureLifecycle(_ => writer);
+            lifecycle.StartTestContainer(new() { uuid = "foo" });
+            lifecycle.StartBeforeFixture(new());
+            lifecycle.StopFixture();
+            lifecycle.StopTestContainer();
+
+            lifecycle.WriteTestContainer();
+
+            Assert.That(writer.testContainers, Has.One.Items);
+        }
+
+        [Test]
+        public void ContainerWithAfterFixtureIsWritten()
+        {
+            var writer = new InMemoryResultsWriter();
+            var lifecycle = new AllureLifecycle(_ => writer);
+            lifecycle.StartTestContainer(new() { uuid = "foo" });
+            lifecycle.StartAfterFixture(new());
+            lifecycle.StopFixture();
+            lifecycle.StopTestContainer();
+
+            lifecycle.WriteTestContainer();
+
+            Assert.That(writer.testContainers, Has.One.Items);
+        }
     }
 }

Allure.Net.Commons/AllureLifecycle.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.IO;
+using System.Linq;
 using System.Threading;
 using Allure.Net.Commons.Configuration;
 using Allure.Net.Commons.Functions;
@@ -264,7 +265,10 @@ public virtual AllureLifecycle WriteTestContainer()
     {
         var container = this.Context.CurrentContainer;
         this.UpdateContext(c => c.WithNoLastContainer());
-        this.writer.Write(container);
+        if (container.befores.Any() || container.afters.Any())
+        {
+            this.writer.Write(container);
+        }
         return this;
     }