Add error log test (#15768)

Content.IntegrationTests/Tests/LogErrorTest.cs

@@ -0,0 +1,33 @@
+using System.Threading.Tasks;
+using NUnit.Framework;
+using Robust.Shared.Configuration;
+using Robust.Shared.Log;
+using Robust.UnitTesting;
+
+namespace Content.IntegrationTests.Tests;
+
+public sealed class LogErrorTest
+{
+    /// <summary>
+    ///     This test ensures that error logs cause tests to fail.
+    /// </summary>
+    [Test]
+    public async Task TestLogErrorCausesTestFailure()
+    {
+        await using var pairTracker = await PoolManager.GetServerClient();
+        var server = pairTracker.Pair.Server;
+        var client = pairTracker.Pair.Client;
+
+        var cfg = server.ResolveDependency<IConfigurationManager>();
+
+        // Default cvar is properly configured
+        Assert.That(cfg.GetCVar(RTCVars.FailureLogLevel), Is.EqualTo(LogLevel.Error));
+
+        // Warnings don't cause tests to fail.
+        await server.WaitPost(() => Logger.Warning("test"));
+
+        // But errors do
+        await server.WaitPost(() => Assert.Throws<AssertionException>(() => Logger.Error("test")));
+        await client.WaitPost(() => Assert.Throws<AssertionException>(() => Logger.Error("test")));
+    }
+}