WIP: Threading fixes

Author: andyleejordan

src/PowerShellEditorServices/Services/PowerShell/Host/PsesInternalHost.cs

@@ -245,6 +245,7 @@ public void TriggerShutdown()
             if (Interlocked.Exchange(ref _shuttingDown, 1) == 0)
             {
                 _cancellationContext.CancelCurrentTaskStack();
+                _pipelineThread.Join();
             }
         }
 

test/PowerShellEditorServices.Test/Debugging/DebugServiceTests.cs

@@ -59,12 +59,11 @@ public void Dispose()
         {
             debugService.Abort();
             _psesHost.StopAsync().GetAwaiter().GetResult();
-            GC.SuppressFinalize(this);
         }
 
         private void DebugService_DebuggerStopped(object sender, DebuggerStoppedEventArgs e)
         {
-            _ = Task.Run(() => debuggerStoppedQueue.Add(e));
+            debuggerStoppedQueue.Add(e);
         }
 
         private ScriptFile GetDebugScript(string fileName)
@@ -477,13 +476,14 @@ await debugService.SetLineBreakpointsAsync(
         }
 
         [Trait("Category", "DebugService")]
-        [Fact(Skip = "This test has a race condition.")]
+        [Fact]
         public async Task DebuggerBreaksWhenRequested()
         {
             var confirmedBreakpoints = await GetConfirmedBreakpoints(debugScriptFile).ConfigureAwait(false);
             Assert.Equal(0, confirmedBreakpoints.Count);
             Task _ = ExecuteDebugFile();
-            debugService.Break();
+            // NOTE: This must be run on a separate thread so the async event handlers can fire.
+            await Task.Run(() => debugService.Break()).ConfigureAwait(false);
             AssertDebuggerPaused();
         }
 
@@ -492,7 +492,8 @@ public async Task DebuggerBreaksWhenRequested()
         public async Task DebuggerRunsCommandsWhileStopped()
         {
             Task _ = ExecuteDebugFile();
-            debugService.Break();
+            // NOTE: This must be run on a separate thread so the async event handlers can fire.
+            await Task.Run(() => debugService.Break()).ConfigureAwait(false);
             AssertDebuggerPaused();
 
             // Try running a command from outside the pipeline thread