Fixing self host startup issues

Author: mathewc

src/WebJobs.Script/Host/ScriptHost.cs

@@ -101,7 +101,7 @@ protected internal ScriptHost(IScriptHostEnvironment environment,
 #if FEATURE_NODE
             NodeFunctionInvoker.UnhandledException += OnUnhandledException;
 #endif
-            TraceWriter = ScriptConfig.TraceWriter.WithDefaults(ScriptConstants.TraceSourceScriptHost, _instanceId);
+            TraceWriter = ScriptConfig.TraceWriter;
             EventManager = eventManager;
 
             _settingsManager = settingsManager ?? ScriptSettingsManager.Instance;
@@ -558,7 +558,7 @@ private void PreInitialize()
             // taking this snapshot once and reusing at various points during initialization allows us to
             // minimize disk operations
             _directorySnapshot = Directory.EnumerateDirectories(ScriptConfig.RootScriptPath).ToImmutableArray();
-            TraceWriter.Verbose("Created directory snapshot.");
+            TraceWriter?.Verbose("Created directory snapshot.");
         }
 
         /// <summary>
@@ -800,6 +800,11 @@ private void ConfigureLogging()
                 .Filter(p => { return true; })
                 .Subscribe(HandleHostError);
 
+            if (TraceWriter != null)
+            {
+                TraceWriter = TraceWriter.WithDefaults(ScriptConstants.TraceSourceScriptHost, _instanceId);
+            }
+
             _hostConfig.Tracing.Tracers.Add(_traceMonitor);
             var hostTraceLevel = _hostConfig.Tracing.ConsoleLevel;
             if (ScriptConfig.FileLoggingMode != FileLoggingMode.Never)

test/WebJobs.Script.Tests.Integration/Host/ScriptHostManagerTests.cs

@@ -484,6 +484,33 @@ await TestHelpers.Await(() =>
             Assert.Equal(ScriptHostState.Running, hostManager.State);
         }
 
+        [Fact]
+        public async Task RunAndBlock_SelfHost_Succeeds()
+        {
+            var traceWriter = new TestTraceWriter(TraceLevel.Verbose);
+            ScriptHostConfiguration config = new ScriptHostConfiguration()
+            {
+                RootScriptPath = Environment.CurrentDirectory,
+                TraceWriter = traceWriter,
+                IsSelfHost = true
+            };
+
+            TraceEvent[] traces = null;
+            using (var manager = new ScriptHostManager(config, _settingsManager))
+            {
+                var tIgnore = Task.Run(() => manager.RunAndBlock());
+
+                await TestHelpers.Await(() =>
+                {
+                    traces = traceWriter.GetTraces().ToArray();
+                    return manager.State == ScriptHostState.Error || traces.Any(p => p.Message.Contains("Job host started"));
+                });
+
+                Assert.Equal(ScriptHostState.Running, manager.State);
+                Assert.Equal(0, traces.Count(p => p.Level == TraceLevel.Error));
+            }
+        }
+
         [Fact]
         public void IsHostHealthy_ReturnsExpectedResult()
         {
@@ -553,12 +580,13 @@ public async Task EmptyHost_StartsSuccessfully()
             };
             File.WriteAllText(Path.Combine(functionDir, ScriptConstants.HostMetadataFileName), hostConfig.ToString());
 
+            var testTraceWriter = new TestTraceWriter(TraceLevel.Info);
             ScriptHostConfiguration config = new ScriptHostConfiguration()
             {
                 RootScriptPath = functionDir,
                 RootLogPath = logDir,
                 FileLoggingMode = FileLoggingMode.Always,
-                TraceWriter = new TestTraceWriter(TraceLevel.Info)
+                TraceWriter = testTraceWriter
             };
 
             var eventManagerMock = new Mock<IScriptEventManager>();
@@ -577,15 +605,11 @@ public async Task EmptyHost_StartsSuccessfully()
             hostManager.Stop();
             Assert.Equal(ScriptHostState.Default, hostManager.State);
 
-            await Task.Delay(FileTraceWriter.LogFlushIntervalMs);
-
-            string hostLogFilePath = Directory.EnumerateFiles(Path.Combine(logDir, "Host")).Single();
-            string hostLogs = File.ReadAllText(hostLogFilePath);
-
-            Assert.Contains("Generating 0 job function(s)", hostLogs);
-            Assert.Contains("No job functions found.", hostLogs);
-            Assert.Contains("Job host started", hostLogs);
-            Assert.Contains("Job host stopped", hostLogs);
+            var logs = testTraceWriter.GetTraces().Select(p => p.Message).ToArray();
+            Assert.True(logs.Any(p => p == "Generating 0 job function(s)"));
+            Assert.True(logs.Any(p => p.StartsWith("No job functions found.")));
+            Assert.True(logs.Any(p => p == "Job host started"));
+            Assert.True(logs.Any(p => p == "Job host stopped"));
         }
 
         [Fact]

test/WebJobs.Script.Tests.Integration/Host/WebScriptHostManagerTests.cs

@@ -395,7 +395,7 @@ public Fixture()
                 };
                 foreach (string pattern in expectedPatterns)
                 {
-                    Assert.True(EventGenerator.Events.Any(p => Regex.IsMatch(p, pattern)), $"Expected trace event {pattern} not found.");
+                    Assert.True(EventGenerator.Events.Any(p => Regex.IsMatch(p, pattern)), $"Expected trace event '{pattern}' not found.");
                 }
             }