Return metadata provider task whether it is successful or not (#10598)

Author: liliankasem

src/WebJobs.Script/Host/FunctionMetadataManager.cs

@@ -236,7 +236,7 @@ private void AddMetadataFromCustomProviders(IEnumerable<IFunctionProvider> funct
 
                 var completedTask = Task.WhenAny(getFunctionMetadataFromProviderTask, delayTask).ContinueWith(t =>
                 {
-                    if (t.Result == getFunctionMetadataFromProviderTask && getFunctionMetadataFromProviderTask.IsCompletedSuccessfully)
+                    if (t.Result == getFunctionMetadataFromProviderTask)
                     {
                         return getFunctionMetadataFromProviderTask.Result;
                     }

test/WebJobs.Script.Tests/FunctionMetadataManagerTests.cs

@@ -7,6 +7,7 @@
 using System.Collections.ObjectModel;
 using System.IO;
 using System.Linq;
+using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Azure.WebJobs.Script.Description;
 using Microsoft.Azure.WebJobs.Script.Workers.Http;
@@ -222,6 +223,34 @@ public void FunctionMetadataManager_LoadFunctionMetadata_Throws_WhenFunctionProv
             Assert.DoesNotContain(traces, t => t.FormattedMessage.Contains("2 functions found (Custom)"));
         }
 
+        [Fact]
+        public void FunctionMetadataManager_LoadFunctionMetadata_BadMetadataProvider_ReturnsFailedTask()
+        {
+            var functionMetadataCollection = new Collection<FunctionMetadata>();
+            var mockFunctionErrors = new Dictionary<string, ImmutableArray<string>>();
+            var mockFunctionMetadataProvider = new Mock<IFunctionMetadataProvider>();
+            var badFunctionMetadataProvider = new Mock<IFunctionProvider>();
+            var workerConfigs = TestHelpers.GetTestWorkerConfigs();
+            var testLoggerProvider = new TestLoggerProvider();
+            var loggerFactory = new LoggerFactory();
+            loggerFactory.AddProvider(testLoggerProvider);
+
+            mockFunctionMetadataProvider.Setup(m => m.GetFunctionMetadataAsync(workerConfigs, SystemEnvironment.Instance, false)).Returns(Task.FromResult(new Collection<FunctionMetadata>().ToImmutableArray()));
+            mockFunctionMetadataProvider.Setup(m => m.FunctionErrors).Returns(new Dictionary<string, ICollection<string>>().ToImmutableDictionary(kvp => kvp.Key, kvp => kvp.Value.ToImmutableArray()));
+
+            // A bad provider that returns a faulty task
+            var tcs = new TaskCompletionSource<ImmutableArray<FunctionMetadata>>();
+            badFunctionMetadataProvider
+                .Setup(m => m.GetFunctionMetadataAsync())
+                .Returns(Task.FromException<ImmutableArray<FunctionMetadata>>(new Exception("Simulated failure")));
+
+            FunctionMetadataManager testFunctionMetadataManager = TestFunctionMetadataManager.GetFunctionMetadataManager(new OptionsWrapper<ScriptJobHostOptions>(_scriptJobHostOptions),
+                mockFunctionMetadataProvider.Object, new List<IFunctionProvider>() { badFunctionMetadataProvider.Object }, new OptionsWrapper<HttpWorkerOptions>(_defaultHttpWorkerOptions), loggerFactory, new TestOptionsMonitor<LanguageWorkerOptions>(TestHelpers.GetTestLanguageWorkerOptions()));
+
+            var exception = Assert.Throws<AggregateException>(() => testFunctionMetadataManager.LoadFunctionMetadata());
+            Assert.Contains("Simulated failure", exception.InnerException.Message);
+        }
+
         [Fact]
         public void FunctionMetadataManager_LoadFunctionMetadata_Throws_WhenFunctionProvidersTimesOut()
         {