Re-enable DotNet.Watcher.Tests

Author: Simon Zhao (BEYONDSOFT CONSULTING INC)

test/dotnet-watch.Tests/TestUtilities/WatchableApp.cs

@@ -65,9 +65,9 @@ public async Task<string> AssertOutputLineStartsWith(string expectedPrefix, Pred
         {
             Logger.Log($"Test waiting for output: '{expectedPrefix}'", testPath, testLine);
 
-            var line = await Process.GetOutputLineAsync(
-                success: line => line.StartsWith(expectedPrefix, StringComparison.Ordinal),
-                failure: failure ?? new Predicate<string>(line => line.Contains(WatchErrorOutputEmoji, StringComparison.Ordinal)));
+            var line = await TryGetOutputLineWithDelayAsync(
+                expectedPrefix,
+                failure ?? new Predicate<string>(line => line.Contains(WatchErrorOutputEmoji, StringComparison.Ordinal)));
 
             if (line == null)
             {
@@ -171,5 +171,28 @@ public void SendKey(char c)
             Process.Process.StandardInput.Write(c);
             Process.Process.StandardInput.Flush();
         }
+
+        private async Task<string> TryGetOutputLineWithDelayAsync(string expectedPrefix, Predicate<string> failure, int maxAttempts = 2)
+        {
+            for (int attempt = 0; attempt < maxAttempts; attempt++)
+            {
+                if (attempt > 0)
+                {
+                    Logger.Log($"Retrying to find output with prefix: '{expectedPrefix}' (attempt {attempt + 1}/{maxAttempts})");
+                    await Task.Delay(TimeSpan.FromSeconds(1));
+                }
+
+                var line = await Process.GetOutputLineAsync(
+                    success: line => line.StartsWith(expectedPrefix, StringComparison.Ordinal),
+                    failure: failure);
+
+                if (line is not null)
+                {
+                    return line;
+                }
+            }
+
+            return null;
+        }
     }
 }

test/dotnet-watch.Tests/Watch/GlobbingAppTests.cs

@@ -12,7 +12,7 @@ public GlobbingAppTests(ITestOutputHelper logger)
         {
         }
 
-        [ConditionalTheory(Skip = "https://github.com/dotnet/sdk/issues/42921")]
+        [ConditionalTheory]
         [InlineData(true)]
         [InlineData(false)]
         public async Task ChangeCompiledFile(bool usePollingWatcher)
@@ -34,7 +34,7 @@ public async Task ChangeCompiledFile(bool usePollingWatcher)
             await AssertCompiledAppDefinedTypes(expected: 2);
         }
 
-        [Fact(Skip = "https://github.com/dotnet/sdk/issues/42921")]
+        [Fact]
         public async Task DeleteCompiledFile()
         {
             var testAsset = TestAssets.CopyTestAsset(AppName)
@@ -51,7 +51,7 @@ public async Task DeleteCompiledFile()
             await AssertCompiledAppDefinedTypes(expected: 1);
         }
 
-        [Fact(Skip = "https://github.com/dotnet/sdk/issues/42921")]
+        [Fact]
         public async Task DeleteSourceFolder()
         {
             var testAsset = TestAssets.CopyTestAsset(AppName)
@@ -68,7 +68,7 @@ public async Task DeleteSourceFolder()
             await AssertCompiledAppDefinedTypes(expected: 1);
         }
 
-        [Fact(Skip = "https://github.com/dotnet/sdk/issues/42921")]
+        [Fact]
         public async Task RenameCompiledFile()
         {
             var testAsset = TestAssets.CopyTestAsset(AppName)
@@ -85,7 +85,7 @@ public async Task RenameCompiledFile()
             await App.AssertStarted();
         }
 
-        [Fact(Skip = "https://github.com/dotnet/sdk/issues/42921")]
+        [Fact]
         public async Task ChangeExcludedFile()
         {
             var testAsset = TestAssets.CopyTestAsset(AppName)

test/dotnet-watch.Tests/Watch/NoDepsAppTests.cs

@@ -7,7 +7,7 @@ public class NoDepsAppTests(ITestOutputHelper logger) : DotNetWatchTestBase(logg
     {
         private const string AppName = "WatchNoDepsApp";
 
-        [Fact(Skip = "https://github.com/dotnet/sdk/issues/42921")]
+        [Fact]
         public async Task RestartProcessOnFileChange()
         {
             var testAsset = TestAssets.CopyTestAsset(AppName)