Fixing flaky tests

Author: mathewc

src/WebJobs.Script/Description/Node/NodeFunctionInvoker.cs

@@ -261,8 +261,17 @@ private Dictionary<string, object> CreateScriptExecutionContext(object input, Da
                 string text = p as string;
                 if (text != null)
                 {
-                    traceWriter.Info(text);
-                    fileTraceWriter.Info(text);
+                    try
+                    {
+                        fileTraceWriter.Info(text);
+                        traceWriter.Info(text);
+                    }
+                    catch (ObjectDisposedException)
+                    {
+                        // if a function attempts to write to a disposed
+                        // TraceWriter. Might happen if a function tries to
+                        // log after calling done()
+                    }
                 } 
 
                 return Task.FromResult<object>(null);

test/WebJobs.Script.Tests/NodeEndToEndTests.cs

@@ -220,19 +220,20 @@ public async Task Scenario_DoneCalledMultipleTimes_ErrorIsLogged()
             {
                 { "input", input.ToString() }
             };
-            await Fixture.Host.CallAsync("Scenarios", arguments);
 
-            var logs = await TestHelpers.GetFunctionLogsAsync("Scenarios");
+            // call a few times since this is a timing related error
+            for (int i = 0; i < 3; i++)
+            {
+                await Fixture.Host.CallAsync("Scenarios", arguments);
+            }
 
-            Assert.Equal(4, logs.Count);
-            Assert.True(logs.Any(p => p.Contains("Function started")));
-            Assert.True(logs.Any(p => p.Contains("Running scenario 'doubleDone'")));
+            var logs = await TestHelpers.GetFunctionLogsAsync("Scenarios");
 
-            // verify an error was written
+            // verify an error was written at least once
             Assert.True(logs.Any(p => p.Contains("Error: 'done' has already been called. Please check your script for extraneous calls to 'done'.")));
 
-            // verify the function completed successfully
-            Assert.True(logs.Any(p => p.Contains("Function completed (Success")));
+            // verify the function completed successfully each time
+            Assert.Equal(3, logs.Count(p => p.Contains("Function completed (Success")));
         }
 
         [Fact]

test/WebJobs.Script.Tests/ScriptHostManagerTests.cs

@@ -96,7 +96,6 @@ public void RunAndBlock_DisposesOfHost_WhenExceptionIsThrown()
             hostMock.Protected().Verify("Dispose", Times.Once(), true);
         }
 
-/*
         [Fact]
         public async Task RunAndBlock_SetsLastError_WhenExceptionIsThrown()
         {
@@ -141,7 +140,6 @@ await TestHelpers.Await(() =>
 
             Assert.Null(mockHostManager.Object.LastError);
         }
-*/
 
         [Fact]
         public async Task EmptyHost_StartsSuccessfully()
@@ -173,6 +171,8 @@ public async Task EmptyHost_StartsSuccessfully()
             hostManager.Stop();
             Assert.False(hostManager.IsRunning);
 
+            await Task.Delay(FileTraceWriter.LogFlushIntervalMs);
+
             string hostLogFilePath = Directory.EnumerateFiles(Path.Combine(logDir, "Host")).Single();
             string hostLogs = File.ReadAllText(hostLogFilePath);