[wasm][debugger] Fix getting async method locals, and `this`

- async local field names don't start with `<`, surface those
- `this` for the actual async method is in a field named like
`<>4__this`, surface it as the `this` object

3 files changed, 69 insertions, 0 deletions

diff --git a/sdks/wasm/DebuggerTestSuite/Tests.cs b/sdks/wasm/DebuggerTestSuite/Tests.cs
index 5954ab03e4f..d64b66f0a8c 100644
--- a/sdks/wasm/DebuggerTestSuite/Tests.cs
+++ b/sdks/wasm/DebuggerTestSuite/Tests.cs
@@ -704,6 +704,46 @@ namespace DebuggerTests
 			});
 		}
 
+		[Fact]
+		public async Task InspectLocalsInAsyncMethods () {
+			var insp = new Inspector ();
+			//Collect events
+			var scripts = SubscribeToScripts(insp);
+
+			await Ready();
+			await insp.Ready (async (cli, token) => {
+				var ctx = new DebugTestContext (cli, insp, token, scripts);
+				var debugger_test_loc = "dotnet://debugger-test.dll/debugger-test.cs";
+
+				await SetBreakpoint (debugger_test_loc, 108, 3, ctx);
+				await SetBreakpoint (debugger_test_loc, 118, 3, ctx);
+
+				// Will stop in Asyncmethod0
+				var wait_res = await EvaluateAndCheck (
+					"window.setTimeout(function() { invoke_async_method_with_await(); }, 1);",
+					debugger_test_loc, 108, 3, "MoveNext", ctx, //FIXME:
+					locals_fn: (locals) => {
+						Assert.Equal (4, locals.Count());
+						CheckString (locals, "s", "string from js");
+						CheckNumber (locals, "i", 42);
+						CheckString (locals, "local0", "value0");
+						CheckObject (locals, "this", "Math.NestedInMath");
+					}
+				);
+
+				// TODO: previous frames have async machinery details, so no point checking that right now
+
+				await SendCommandAndCheck (null, "Debugger.resume", debugger_test_loc, 118, 3, "AsyncMethodNoReturn", ctx,
+					locals_fn: (locals) => {
+						Assert.Equal (2, locals.Count());
+						CheckString (locals, "str", "AsyncMethodNoReturn's local");
+						CheckObject (locals, "this", "Math.NestedInMath");
+					}
+				);
+				// TODO: Check `this` properties
+			});
+		}
+
 		async Task<JObject> StepAndCheck (StepKind kind, string script_loc, int line, int column, string function_name, DebugTestContext ctx,
 							Func<JObject, Task> wait_for_event_fn = null, Action<JToken> locals_fn = null, int times=1)
 		{
diff --git a/sdks/wasm/debugger-driver.html b/sdks/wasm/debugger-driver.html
index 42934a154d5..d05034bf976 100644
--- a/sdks/wasm/debugger-driver.html
+++ b/sdks/wasm/debugger-driver.html
@@ -11,6 +11,7 @@
 				this.delegates_test = Module.mono_bind_static_method ("[debugger-test] Math:DelegatesTest");
 				this.generic_types_test = Module.mono_bind_static_method ("[debugger-test] Math:GenericTypesTest");
 				this.outer_method = Module.mono_bind_static_method ("[debugger-test] Math:OuterMethod");
+				this.async_method = Module.mono_bind_static_method ("[debugger-test] Math/NestedInMath:AsyncTest");
 				console.log ("ready");
 			},
 		};
@@ -35,6 +36,9 @@
 			console.log('invoke_outer_method called');
 			return App.outer_method ();
 		}
+		async function invoke_async_method_with_await () {
+			return await App.async_method ("string from js", 42);
+		}
       </script>
       <script type="text/javascript" src="mono-config.js"></script>
       <script type="text/javascript" src="runtime.js"></script>
diff --git a/sdks/wasm/debugger-test.cs b/sdks/wasm/debugger-test.cs
index 18fba8e5b97..094f5152ce6 100644
--- a/sdks/wasm/debugger-test.cs
+++ b/sdks/wasm/debugger-test.cs
@@ -100,5 +100,30 @@ public class Math { //Only append content to this class as the test suite depend
 			Console.WriteLine ($"i: {i} and j: {j}");
 			return j;
 		}
+
+		Math m = new Math ();
+		public async System.Threading.Tasks.Task<bool> AsyncMethod0 (string s, int i)
+		{
+			string local0 = "value0";
+			await System.Threading.Tasks.Task.Delay (1);
+			Console.WriteLine ($"* time for the second await, local0: {local0}");
+			await AsyncMethodNoReturn ();
+			return true;
+		}
+
+		public async System.Threading.Tasks.Task AsyncMethodNoReturn ()
+		{
+			string str = "AsyncMethodNoReturn's local";
+			Console.WriteLine ($"* field m: {m}");
+			await System.Threading.Tasks.Task.Delay (1);
+			Console.WriteLine ($"str: {str}");
+		}
+
+		public static async System.Threading.Tasks.Task<bool> AsyncTest (string s, int i)
+		{
+			return await new NestedInMath().AsyncMethod0 (s, i);
+		}
+
 	}
+
 }