[wasm][debugger] Show signature for delegate, or target, if available (#19505)aj-wasm-dbg-improve-vt-descr

* [wasm][debugger] Show signature for delegate, or target, if available

- As object properties, we return a `Target` which has the signature of
the delegate target.

Fixes https://github.com/mono/mono/issues/19382

* [wasm][debugger] Some tidying up

* [wasm][debugger] Remove unused `sig_desc`

* [wasm][debugger] Simplify code, avoid extra allocations

.. as suggested by @lewing

4 files changed, 635 insertions, 237 deletions

diff --git a/mono/mini/mini-wasm-debugger.c b/mono/mini/mini-wasm-debugger.c
index 7dc7cf68e77..5efb34de635 100644
--- a/mono/mini/mini-wasm-debugger.c
+++ b/mono/mini/mini-wasm-debugger.c
@@ -51,7 +51,8 @@ extern void mono_wasm_add_value_type_unexpanded_var (const char*, const char*);
 extern void mono_wasm_begin_value_type_var (const char*, const char*);
 extern void mono_wasm_end_value_type_var (void);
 extern void mono_wasm_add_enum_var (const char*, const char*, guint64);
-extern void mono_wasm_add_func_var (const char*, guint64);
+extern void mono_wasm_add_func_var (const char*, const char*, guint64);
+extern void mono_wasm_add_symbol_var (const char*);
 extern void mono_wasm_add_array_var (const char*, guint64);
 extern void mono_wasm_add_properties_var (const char*, gint32);
 extern void mono_wasm_add_array_item (int);
@@ -706,6 +707,28 @@ typedef struct {
 	int *pos;
 } FrameDescData;
 
+/*
+ * this returns a string formatted like
+ *
+ *  <ret_type>:[<comma separated list of arg types>]:<method name>
+ *
+ *  .. which is consumed by `mono_wasm_add_func_var`. It is used for
+ *  generating this for the delegate, and it's target.
+ */
+static char*
+mono_method_to_desc_for_js (MonoMethod *method, gboolean include_namespace)
+{
+	MonoMethodSignature *sig = mono_method_signature_internal (method);
+	char *ret_desc = mono_type_full_name (sig->ret);
+	char *args_desc = mono_signature_get_desc (sig, include_namespace);
+
+	char *sig_desc = g_strdup_printf ("%s:%s:%s", ret_desc, args_desc, method->name);
+
+	g_free (ret_desc);
+	g_free (args_desc);
+	return sig_desc;
+}
+
 static guint64
 read_enum_value (const char *mem, int type)
 {
@@ -814,10 +837,27 @@ static gboolean describe_value(MonoType * type, gpointer addr, gboolean expandVa
 			char *class_name = mono_type_full_name (type);
 			int obj_id = get_object_id (obj);
 
-			if (type->type == MONO_TYPE_SZARRAY || type->type == MONO_TYPE_ARRAY) {
-				mono_wasm_add_array_var (class_name, obj_id);
-			} else if (m_class_is_delegate (klass)) {
-				mono_wasm_add_func_var (class_name, obj_id);
+			if (type-> type == MONO_TYPE_ARRAY || type->type == MONO_TYPE_SZARRAY) {
+				mono_wasm_add_array_var(class_name, obj_id);
+			} else if (m_class_is_delegate (klass) || (type->type == MONO_TYPE_GENERICINST && m_class_is_delegate (type->data.generic_class->container_class))) {
+				MonoMethod *method;
+
+				if (type->type == MONO_TYPE_GENERICINST)
+					klass = type->data.generic_class->container_class;
+
+				method = mono_get_delegate_invoke_internal (klass);
+				if (!method) {
+					DEBUG_PRINTF (1, "Could not get a method for the delegate for %s\n", class_name);
+					break;
+				}
+
+				MonoMethod *tm = ((MonoDelegate *)obj)->method;
+				char *tm_desc = NULL;
+				if (tm)
+					tm_desc = mono_method_to_desc_for_js (tm, FALSE);
+
+				mono_wasm_add_func_var (class_name, tm_desc, obj_id);
+				g_free (tm_desc);
 			} else {
 				char *to_string_val = get_to_string_description (class_name, klass, addr);
 				mono_wasm_add_obj_var (class_name, to_string_val, obj_id);
@@ -993,6 +1033,28 @@ describe_object_properties_for_klass (void *obj, MonoClass *klass, gboolean isAs
 	}
 }
 
+/*
+ * We return a `Target` property only for now.
+ * In future, we could add a `MethodInfo` too.
+ */
+static gboolean
+describe_delegate_properties (MonoObject *obj)
+{
+	MonoClass *klass = mono_object_class(obj);
+	if (!m_class_is_delegate (klass))
+		return FALSE;
+
+	// Target, like in VS - what is this field supposed to be, anyway??
+	MonoMethod *tm = ((MonoDelegate *)obj)->method;
+	char * sig_desc = mono_method_to_desc_for_js (tm, FALSE);
+
+	mono_wasm_add_properties_var ("Target", -1);
+	mono_wasm_add_func_var (NULL, sig_desc, -1);
+
+	g_free (sig_desc);
+	return TRUE;
+}
+
 static gboolean
 describe_object_properties (guint64 objectId, gboolean isAsyncLocalThis, gboolean expandValueType)
 {
@@ -1009,7 +1071,13 @@ describe_object_properties (guint64 objectId, gboolean isAsyncLocalThis, gboolea
 		return FALSE;
 	}
 
-	describe_object_properties_for_klass (obj, obj->vtable->klass, isAsyncLocalThis, expandValueType);
+	if (m_class_is_delegate (mono_object_class (obj))) {
+		// delegates get the same id format as regular objects
+		describe_delegate_properties (obj);
+	} else {
+		describe_object_properties_for_klass (obj, obj->vtable->klass, isAsyncLocalThis, expandValueType);
+	}
+
 	return TRUE;
 }
 
diff --git a/sdks/wasm/DebuggerTestSuite/Tests.cs b/sdks/wasm/DebuggerTestSuite/Tests.cs
index 5640f713bf1..e781755954e 100644
--- a/sdks/wasm/DebuggerTestSuite/Tests.cs
+++ b/sdks/wasm/DebuggerTestSuite/Tests.cs
@@ -332,21 +332,6 @@ namespace DebuggerTests
 			Assert.True(false, $"Could not find variable '{name}'");
 		}
 
-		void CheckFunction (JToken locals, string name, string description, string subtype=null) {
-			Console.WriteLine ($"** Locals: {locals.ToString ()}");
-			foreach (var l in locals) {
-				if (name != l["name"]?.Value<string> ())
-					continue;
-
-				var val = l["value"];
-				Assert.Equal ("function", val ["type"]?.Value<string> ());
-				Assert.Equal (description, val ["description"]?.Value<string> ());
-				Assert.Equal (subtype, val ["subtype"]?.Value<string> ());
-				return;
-			}
-			Assert.True(false, $"Could not find variable '{name}'");
-		}
-
 		JToken GetAndAssertObjectWithName (JToken obj, string name)
 		{
 			var l = obj.FirstOrDefault (jt => jt ["name"]?.Value<string> () == name);
@@ -385,22 +370,29 @@ namespace DebuggerTests
 			await CheckInspectLocalsAtBreakpointSite (
 				"dotnet://debugger-test.dll/debugger-test.cs", 41, 2, "DelegatesTest",
 				"window.setTimeout(function() { invoke_delegates_test (); }, 1);",
-				test_fn: (locals) => {
-					CheckObject (locals, "fn_func", "System.Func<Math, bool>");
-					CheckObject (locals, "fn_func_null", "System.Func<Math, bool>", is_null: true);
-					CheckArray (locals, "fn_func_arr", "System.Func<Math, bool>[]");
-					CheckFunction (locals, "fn_del", "Math.IsMathNull");
-					CheckObject (locals, "fn_del_null", "Math.IsMathNull", is_null: true);
-					CheckArray (locals, "fn_del_arr", "Math.IsMathNull[]");
-
-					// Unused locals
-					CheckObject (locals, "fn_func_unused", "System.Func<Math, bool>", is_null: true);
-					CheckObject (locals, "fn_func_null_unused", "System.Func<Math, bool>", is_null: true);
-					CheckObject (locals, "fn_func_arr_unused", "System.Func<Math, bool>[]", is_null: true);
-
-					CheckObject (locals, "fn_del_unused", "Math.IsMathNull", is_null: true);
-					CheckObject (locals, "fn_del_null_unused", "Math.IsMathNull", is_null: true);
-					CheckObject (locals, "fn_del_arr_unused", "Math.IsMathNull[]", is_null: true);
+				wait_for_event_fn: async (pause_location) => {
+					var locals = await GetProperties(pause_location["callFrames"][0]["callFrameId"].Value<string>());
+
+					await CheckProps (locals, new {
+						fn_func			= TDelegate ("System.Func<Math, bool>", "bool <DelegatesTest>|(Math)"),
+						fn_func_null		= TObject   ("System.Func<Math, bool>", is_null: true),
+						fn_func_arr		= TArray    ("System.Func<Math, bool>[]"),
+						fn_del			= TDelegate ("Math.IsMathNull", "bool IsMathNullDelegateTarget (Math)"),
+						fn_del_null		= TObject   ("Math.IsMathNull", is_null: true),
+						fn_del_arr		= TArray    ("Math.IsMathNull[]"),
+
+						// Unused locals
+						fn_func_unused		= TObject   ("System.Func<Math, bool>", is_null: true),
+						fn_func_null_unused	= TObject   ("System.Func<Math, bool>", is_null: true),
+						fn_func_arr_unused	= TObject   ("System.Func<Math, bool>[]", is_null: true),
+
+						fn_del_unused		= TObject   ("Math.IsMathNull", is_null: true),
+						fn_del_null_unused	= TObject   ("Math.IsMathNull", is_null: true),
+						fn_del_arr_unused	= TObject   ("Math.IsMathNull[]", is_null: true),
+
+						res			= TBool     (false),
+						m_obj			= TObject   ("Math")
+					}, "locals");
 				}
 			);
 
@@ -425,7 +417,202 @@ namespace DebuggerTests
 				}
 			);
 
-		async Task CheckInspectLocalsAtBreakpointSite (string url_key, int line, int column, string function_name, string eval_expression, Action<JToken> test_fn) {
+		[Fact]
+		public async Task InspectDelegateSignaturesWithFunc ()
+			=> await CheckInspectLocalsAtBreakpointSite (
+				"dotnet://debugger-test.dll/debugger-test.cs",
+				185, 2,
+				"DelegatesSignatureTest",
+				"window.setTimeout (function () { invoke_static_method ('[debugger-test] Math:DelegatesSignatureTest'); }, 1)",
+				wait_for_event_fn: async (pause_location) => {
+					var locals = await GetProperties (pause_location ["callFrames"][0]["callFrameId"].Value<string>());
+
+					await CheckProps (locals, new {
+						fn_func		= TDelegate  ("System.Func<Math, Math.GenericStruct<Math.GenericStruct<int[]>>, Math.GenericStruct<bool[]>>",
+									      "Math.GenericStruct<bool[]> <DelegatesSignatureTest>|(Math,Math.GenericStruct<Math.GenericStruct<int[]>>)"),
+
+						fn_func_del	= TDelegate  ("System.Func<Math, Math.GenericStruct<Math.GenericStruct<int[]>>, Math.GenericStruct<bool[]>>",
+									      "Math.GenericStruct<bool[]> DelegateTargetForSignatureTest (Math,Math.GenericStruct<Math.GenericStruct<int[]>>)"),
+
+						fn_func_null	= TObject    ("System.Func<Math, Math.GenericStruct<Math.GenericStruct<int[]>>, Math.GenericStruct<bool[]>>", is_null: true),
+						fn_func_only_ret= TDelegate  ("System.Func<bool>", "bool <DelegatesSignatureTest>|()"),
+						fn_func_arr	= TArray     ("System.Func<Math, Math.GenericStruct<Math.GenericStruct<int[]>>, Math.GenericStruct<bool[]>>[]"),
+
+						fn_del		= TDelegate  ("Math.DelegateForSignatureTest",
+									      "Math.GenericStruct<bool[]> DelegateTargetForSignatureTest (Math,Math.GenericStruct<Math.GenericStruct<int[]>>)"),
+
+						fn_del_l	=  TDelegate ("Math.DelegateForSignatureTest",
+									      "Math.GenericStruct<bool[]> <DelegatesSignatureTest>|(Math,Math.GenericStruct<Math.GenericStruct<int[]>>)"),
+
+						fn_del_null	= TObject    ("Math.DelegateForSignatureTest", is_null: true),
+						fn_del_arr	= TArray     ("Math.DelegateForSignatureTest[]"),
+						m_obj		= TObject    ("Math"),
+						gs_gs		= TValueType ("Math.GenericStruct<Math.GenericStruct<int[]>>"),
+						fn_void_del	= TDelegate  ("Math.DelegateWithVoidReturn",
+									      "void DelegateTargetWithVoidReturn (Math.GenericStruct<int[]>)"),
+
+						fn_void_del_arr	= TArray     ("Math.DelegateWithVoidReturn[]"),
+						fn_void_del_null= TObject    ("Math.DelegateWithVoidReturn", is_null: true),
+						gs		= TValueType ("Math.GenericStruct<int[]>"),
+						rets		= TArray     ("Math.GenericStruct<bool[]>[]")
+					}, "locals");
+
+					await CompareObjectPropertiesFor (locals, "fn_func_arr", new [] {
+						TDelegate (
+							"System.Func<Math, Math.GenericStruct<Math.GenericStruct<int[]>>, Math.GenericStruct<bool[]>>",
+							"Math.GenericStruct<bool[]> <DelegatesSignatureTest>|(Math,Math.GenericStruct<Math.GenericStruct<int[]>>)"),
+					}, "locals#fn_func_arr");
+
+					await CompareObjectPropertiesFor (locals, "fn_del_arr", new [] {
+						TDelegate (
+							"Math.DelegateForSignatureTest",
+							"Math.GenericStruct<bool[]> DelegateTargetForSignatureTest (Math,Math.GenericStruct<Math.GenericStruct<int[]>>)"),
+						TDelegate (
+							"Math.DelegateForSignatureTest",
+							"Math.GenericStruct<bool[]> <DelegatesSignatureTest>|(Math,Math.GenericStruct<Math.GenericStruct<int[]>>)")
+					}, "locals#fn_del_arr");
+
+					await CompareObjectPropertiesFor (locals, "fn_void_del_arr", new [] {
+						TDelegate (
+							"Math.DelegateWithVoidReturn",
+							"void DelegateTargetWithVoidReturn (Math.GenericStruct<int[]>)")
+					}, "locals#fn_void_del_arr");
+				});
+
+		[Fact]
+		public async Task ActionTSignatureTest ()
+			=> await CheckInspectLocalsAtBreakpointSite (
+				"dotnet://debugger-test.dll/debugger-test.cs", 206, 2,
+				"ActionTSignatureTest",
+				"window.setTimeout (function () { invoke_static_method ('[debugger-test] Math:ActionTSignatureTest'); }, 1)",
+				wait_for_event_fn: async (pause_location) => {
+					var locals = await GetProperties (pause_location ["callFrames"][0]["callFrameId"].Value<string>());
+
+					await CheckProps (locals, new
+					{
+						fn_action	= TDelegate  ("System.Action<Math.GenericStruct<int[]>>",
+									      "void <ActionTSignatureTest>|(Math.GenericStruct<int[]>)"),
+						fn_action_del	= TDelegate  ("System.Action<Math.GenericStruct<int[]>>",
+									      "void DelegateTargetWithVoidReturn (Math.GenericStruct<int[]>)"),
+						fn_action_bare  = TDelegate  ("System.Action",
+									      "void|()"),
+
+						fn_action_null	= TObject    ("System.Action<Math.GenericStruct<int[]>>", is_null: true),
+
+						fn_action_arr	= TArray     ("System.Action<Math.GenericStruct<int[]>>[]"),
+
+						gs		= TValueType ("Math.GenericStruct<int[]>"),
+					}, "locals");
+
+					await CompareObjectPropertiesFor (locals, "fn_action_arr", new [] {
+						TDelegate (
+							"System.Action<Math.GenericStruct<int[]>>",
+							"void <ActionTSignatureTest>|(Math.GenericStruct<int[]>)"),
+						TDelegate (
+							"System.Action<Math.GenericStruct<int[]>>",
+							"void DelegateTargetWithVoidReturn (Math.GenericStruct<int[]>)"),
+						TObject ("System.Action<Math.GenericStruct<int[]>>", is_null: true)
+					}, "locals#fn_action_arr");
+				});
+
+		[Fact]
+		public async Task NestedDelegatesTest ()
+			=> await CheckInspectLocalsAtBreakpointSite (
+				"dotnet://debugger-test.dll/debugger-test.cs", 225, 2,
+				"NestedDelegatesTest",
+				"window.setTimeout (function () { invoke_static_method ('[debugger-test] Math:NestedDelegatesTest'); }, 1)",
+				wait_for_event_fn: async (pause_location) => {
+					var locals = await GetProperties (pause_location ["callFrames"][0]["callFrameId"].Value<string>());
+
+					await CheckProps (locals, new {
+						fn_func		= TDelegate ("System.Func<System.Func<int, bool>, bool>",
+									     "bool <NestedDelegatesTest>|(Func<int, bool>)"),
+						fn_func_null 	= TObject   ("System.Func<System.Func<int, bool>, bool>", is_null: true),
+						fn_func_arr	= TArray    ("System.Func<System.Func<int, bool>, bool>[]"),
+						fn_del_arr	= TArray    ("System.Func<System.Func<int, bool>, bool>[]"),
+
+						m_obj		= TObject   ("Math"),
+						fn_del_null	= TObject   ("System.Func<System.Func<int, bool>, bool>", is_null: true),
+						fs		= TDelegate ("System.Func<int, bool>",
+									     "bool <NestedDelegatesTest>|(int)")
+					}, "locals");
+
+					await CompareObjectPropertiesFor (locals, "fn_func_arr", new [] {
+						TDelegate (
+							"System.Func<System.Func<int, bool>, bool>",
+							"bool <NestedDelegatesTest>|(System.Func<int, bool>)")
+					}, "locals#fn_func_arr");
+
+					await CompareObjectPropertiesFor (locals, "fn_del_arr", new [] {
+						TDelegate (
+							"System.Func<System.Func<int, bool>, bool>",
+							"bool DelegateTargetForNestedFunc (Func<int, bool>)")
+					}, "locals#fn_del_arr");
+				});
+
+		[Fact]
+		public async Task DelegatesAsMethodArgsTest ()
+			=> await CheckInspectLocalsAtBreakpointSite (
+				"dotnet://debugger-test.dll/debugger-test.cs", 244, 2,
+				"MethodWithDelegateArgs",
+				"window.setTimeout (function () { invoke_static_method ('[debugger-test] Math:DelegatesAsMethodArgsTest'); }, 1)",
+				wait_for_event_fn: async (pause_location) => {
+					var locals = await GetProperties (pause_location ["callFrames"][0]["callFrameId"].Value<string>());
+
+					await CheckProps (locals, new {
+						@this		= TObject   ("Math"),
+						dst_arr		= TArray    ("Math.DelegateForSignatureTest[]"),
+						fn_func		= TDelegate ("System.Func<char[], bool>",
+									     "bool <DelegatesAsMethodArgsTest>|(char[])"),
+						fn_action	= TDelegate ("System.Action<Math.GenericStruct<int>[]>",
+									     "void <DelegatesAsMethodArgsTest>|(Math.GenericStruct<int>[])")
+					}, "locals");
+
+					await CompareObjectPropertiesFor (locals, "dst_arr", new [] {
+						TDelegate ("Math.DelegateForSignatureTest",
+							"Math.GenericStruct<bool[]> DelegateTargetForSignatureTest (Math,Math.GenericStruct<Math.GenericStruct<int[]>>)"),
+						TDelegate ("Math.DelegateForSignatureTest",
+							"Math.GenericStruct<bool[]> <DelegatesAsMethodArgsTest>|(Math,Math.GenericStruct<Math.GenericStruct<int[]>>)"),
+					}, "locals#dst_arr");
+				});
+
+		[Fact]
+		public async Task MethodWithDelegatesAsyncTest ()
+			=> await CheckInspectLocalsAtBreakpointSite (
+				"dotnet://debugger-test.dll/debugger-test.cs", 262, 2,
+				"MoveNext", //"DelegatesAsMethodArgsTestAsync"
+				"window.setTimeout (function () { invoke_static_method_async ('[debugger-test] Math:MethodWithDelegatesAsyncTest'); }, 1)",
+				wait_for_event_fn: async (pause_location) => {
+					var locals = await GetProperties (pause_location ["callFrames"][0]["callFrameId"].Value<string>());
+
+					await CheckProps (locals, new {
+						@this		= TObject   ("Math"),
+						_dst_arr	= TArray    ("Math.DelegateForSignatureTest[]"),
+						_fn_func 	= TDelegate ("System.Func<char[], bool>",
+									     "bool <MethodWithDelegatesAsync>|(char[])"),
+						_fn_action	= TDelegate ("System.Action<Math.GenericStruct<int>[]>",
+									     "void <MethodWithDelegatesAsync>|(Math.GenericStruct<int>[])")
+					}, "locals");
+
+					await CompareObjectPropertiesFor (locals, "_dst_arr", new [] {
+						TDelegate (
+							"Math.DelegateForSignatureTest",
+							"Math.GenericStruct<bool[]> DelegateTargetForSignatureTest (Math,Math.GenericStruct<Math.GenericStruct<int[]>>)"),
+						TDelegate (
+							"Math.DelegateForSignatureTest",
+							"Math.GenericStruct<bool[]> <MethodWithDelegatesAsync>|(Math,Math.GenericStruct<Math.GenericStruct<int[]>>)"),
+					}, "locals#dst_arr");
+				});
+
+		object TGenericStruct(string typearg, string stringField)
+			=> new {
+				List = TObject ($"System.Collections.Generic.List<{typearg}>"),
+				StringField = TString (stringField)
+			};
+
+		async Task CheckInspectLocalsAtBreakpointSite (string url_key, int line, int column, string function_name, string eval_expression,
+						Action<JToken> test_fn = null, Func<JObject, Task> wait_for_event_fn = null)
+		{
 			var insp = new Inspector ();
 			//Collect events
 			var scripts = SubscribeToScripts(insp);
@@ -439,7 +626,7 @@ namespace DebuggerTests
 				await EvaluateAndCheck (
 					eval_expression, url_key, line, column,
 					function_name,
-					wait_for_event_fn: (pause_location) => {
+					wait_for_event_fn: async (pause_location) => {
 						//make sure we're on the right bp
 
 						Assert.Equal (bp.Value ["breakpointId"]?.ToString (), pause_location ["hitBreakpoints"]?[0]?.Value<string> ());
@@ -448,7 +635,10 @@ namespace DebuggerTests
 
 						var scope = top_frame ["scopeChain"][0];
 						Assert.Equal ("dotnet:scope:0", scope ["object"]["objectId"]);
-						return Task.CompletedTask;
+						if (wait_for_event_fn != null)
+							await wait_for_event_fn(pause_location);
+						else
+							await Task.CompletedTask;
 					},
 					locals_fn: (locals) => {
 						if (test_fn != null)
@@ -1777,203 +1967,89 @@ namespace DebuggerTests
 
 		[Fact]
 		public async Task EvaluateThisProperties ()
-		{
-			var insp = new Inspector ();
-			//Collect events
-			var scripts = SubscribeToScripts(insp);
-			int line = 18;
-			int col = 16;
-			string entry_method_name = "[debugger-test] DebuggerTests.EvaluateTestsClass:EvaluateLocals";
-
-			await Ready();
-			await insp.Ready (async (cli, token) => {
-				ctx = new DebugTestContext (cli, insp, token, scripts);
-				var debugger_test_loc = "dotnet://debugger-test.dll/debugger-evaluate-test.cs";
-
-				await SetBreakpoint (debugger_test_loc, line, col);
-
-				var eval_expr = "window.setTimeout(function() { invoke_static_method_async ("
-							+ $"'{entry_method_name}'"
-						+ "); }, 1);";
-
-				var pause_location = await EvaluateAndCheck (eval_expr, 
-										debugger_test_loc, 
-										line, 
-										col, 
-										"run",
-										wait_for_event_fn: async (pause_location) => {
-											var locals = await GetProperties (pause_location ["callFrames"][0] ["callFrameId"].Value<string> ());
-											var evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "a");
-											CheckContentValue (evaluate, "1");
-											evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "b");
-											CheckContentValue (evaluate, "2");
-											evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "c");
-											CheckContentValue (evaluate, "3");
-										});
-			});
-		}
+			=> await CheckInspectLocalsAtBreakpointSite (
+				"dotnet://debugger-test.dll/debugger-evaluate-test.cs", 18, 16,
+				"run",
+				"window.setTimeout(function() { invoke_static_method_async ('[debugger-test] DebuggerTests.EvaluateTestsClass:EvaluateLocals'); })",
+				wait_for_event_fn: async (pause_location) => {
+					var locals = await GetProperties (pause_location ["callFrames"][0] ["callFrameId"].Value<string> ());
+					var evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "a");
+					CheckContentValue (evaluate, "1");
+					evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "b");
+					CheckContentValue (evaluate, "2");
+					evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "c");
+					CheckContentValue (evaluate, "3");
+				});
 
 		[Fact]
 		public async Task EvaluateParameters ()
-		{
-			var insp = new Inspector ();
-			//Collect events
-			var scripts = SubscribeToScripts(insp);
-			int line = 18;
-			int col = 16;
-			string entry_method_name = "[debugger-test] DebuggerTests.EvaluateTestsClass:EvaluateLocals";
-
-			await Ready();
-			await insp.Ready (async (cli, token) => {
-				ctx = new DebugTestContext (cli, insp, token, scripts);
-				var debugger_test_loc = "dotnet://debugger-test.dll/debugger-evaluate-test.cs";
-
-				await SetBreakpoint (debugger_test_loc, line, col);
-
-				var eval_expr = "window.setTimeout(function() { invoke_static_method_async ("
-							+ $"'{entry_method_name}'"
-						+ "); }, 1);";
-
-				var pause_location = await EvaluateAndCheck (eval_expr, 
-										debugger_test_loc, 
-										line, 
-										col, 
-										"run",
-										wait_for_event_fn: async (pause_location) => {
-											var locals = await GetProperties (pause_location ["callFrames"][0] ["callFrameId"].Value<string> ());
-											var evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "g");
-											CheckContentValue (evaluate, "100");
-											evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "h");
-											CheckContentValue (evaluate, "200");
-											evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "valString");
-											CheckContentValue (evaluate, "test");
-										});
-			});
-		}
+			=> await CheckInspectLocalsAtBreakpointSite (
+				"dotnet://debugger-test.dll/debugger-evaluate-test.cs", 18, 16,
+				"run",
+				"window.setTimeout(function() { invoke_static_method_async ('[debugger-test] DebuggerTests.EvaluateTestsClass:EvaluateLocals'); })",
+				wait_for_event_fn: async (pause_location) => {
+					var locals = await GetProperties (pause_location ["callFrames"][0] ["callFrameId"].Value<string> ());
+					var evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "g");
+					CheckContentValue (evaluate, "100");
+					evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "h");
+					CheckContentValue (evaluate, "200");
+					evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "valString");
+					CheckContentValue (evaluate, "test");
+				});
 
 		[Fact]
 		public async Task EvaluateLocals ()
-		{
-			var insp = new Inspector ();
-			//Collect events
-			var scripts = SubscribeToScripts(insp);
-			int line = 18;
-			int col = 16;
-			string entry_method_name = "[debugger-test] DebuggerTests.EvaluateTestsClass:EvaluateLocals";
-
-			await Ready();
-			await insp.Ready (async (cli, token) => {
-				ctx = new DebugTestContext (cli, insp, token, scripts);
-				var debugger_test_loc = "dotnet://debugger-test.dll/debugger-evaluate-test.cs";
-
-				await SetBreakpoint (debugger_test_loc, line, col);
-
-				var eval_expr = "window.setTimeout(function() { invoke_static_method_async ("
-							+ $"'{entry_method_name}'"
-						+ "); }, 1);";
-
-				var pause_location = await EvaluateAndCheck (eval_expr, 
-										debugger_test_loc, 
-										line, 
-										col, 
-										"run",
-										wait_for_event_fn: async (pause_location) => {
-											var locals = await GetProperties (pause_location ["callFrames"][0] ["callFrameId"].Value<string> ());
-											var evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "d");
-											CheckContentValue (evaluate, "101");
-											evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "e");
-											CheckContentValue (evaluate, "102");
-											evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "f");
-											CheckContentValue (evaluate, "103");
-										});
-			});
-		}
-
+			=> await CheckInspectLocalsAtBreakpointSite (
+				"dotnet://debugger-test.dll/debugger-evaluate-test.cs", 18, 16,
+				"run",
+				"window.setTimeout(function() { invoke_static_method_async ('[debugger-test] DebuggerTests.EvaluateTestsClass:EvaluateLocals'); })",
+				wait_for_event_fn: async (pause_location) => {
+					var locals = await GetProperties (pause_location ["callFrames"][0] ["callFrameId"].Value<string> ());
+					var evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "d");
+					CheckContentValue (evaluate, "101");
+					evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "e");
+					CheckContentValue (evaluate, "102");
+					evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "f");
+					CheckContentValue (evaluate, "103");
+				});
 
 		[Fact]
 		public async Task EvaluateExpressions ()
-		{
-			var insp = new Inspector ();
-			//Collect events
-			var scripts = SubscribeToScripts(insp);
-			int line = 18;
-			int col = 16;
-			string entry_method_name = "[debugger-test] DebuggerTests.EvaluateTestsClass:EvaluateLocals";
-
-			await Ready();
-			await insp.Ready (async (cli, token) => {
-				ctx = new DebugTestContext (cli, insp, token, scripts);
-				var debugger_test_loc = "dotnet://debugger-test.dll/debugger-evaluate-test.cs";
-
-				await SetBreakpoint (debugger_test_loc, line, col);
-
-				var eval_expr = "window.setTimeout(function() { invoke_static_method_async ("
-							+ $"'{entry_method_name}'"
-						+ "); }, 1);";
-
-				var pause_location = await EvaluateAndCheck (eval_expr, 
-										debugger_test_loc, 
-										line, 
-										col, 
-										"run",
-										wait_for_event_fn: async (pause_location) => {
-											var locals = await GetProperties (pause_location ["callFrames"][0] ["callFrameId"].Value<string> ());
-											var evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "d + e");
-											CheckContentValue (evaluate, "203");
-											evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "e + 10");
-											CheckContentValue (evaluate, "112");
-											evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "a + a");
-											CheckContentValue (evaluate, "2");
-											evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "this.a + this.b");
-											CheckContentValue (evaluate, "3");
-											evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "\"test\" + \"test\"");
-											CheckContentValue (evaluate, "testtest");
-											evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "5 + 5");
-											CheckContentValue (evaluate, "10");
-										});
-			});
-		}
+			=> await CheckInspectLocalsAtBreakpointSite (
+				"dotnet://debugger-test.dll/debugger-evaluate-test.cs", 18, 16,
+				"run",
+				"window.setTimeout(function() { invoke_static_method_async ('[debugger-test] DebuggerTests.EvaluateTestsClass:EvaluateLocals'); })",
+				wait_for_event_fn: async (pause_location) => {
+					var locals = await GetProperties (pause_location ["callFrames"][0] ["callFrameId"].Value<string> ());
+					var evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "d + e");
+					CheckContentValue (evaluate, "203");
+					evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "e + 10");
+					CheckContentValue (evaluate, "112");
+					evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "a + a");
+					CheckContentValue (evaluate, "2");
+					evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "this.a + this.b");
+					CheckContentValue (evaluate, "3");
+					evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "\"test\" + \"test\"");
+					CheckContentValue (evaluate, "testtest");
+					evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "5 + 5");
+					CheckContentValue (evaluate, "10");
+				});
 
 		[Fact]
 		public async Task EvaluateThisExpressions ()
-		{
-			var insp = new Inspector ();
-			//Collect events
-			var scripts = SubscribeToScripts(insp);
-			int line = 18;
-			int col = 16;
-			string entry_method_name = "[debugger-test] DebuggerTests.EvaluateTestsClass:EvaluateLocals";
-
-			await Ready();
-			await insp.Ready (async (cli, token) => {
-				ctx = new DebugTestContext (cli, insp, token, scripts);
-				var debugger_test_loc = "dotnet://debugger-test.dll/debugger-evaluate-test.cs";
-
-				await SetBreakpoint (debugger_test_loc, line, col);
-
-				var eval_expr = "window.setTimeout(function() { invoke_static_method_async ("
-							+ $"'{entry_method_name}'"
-						+ "); }, 1);";
-
-				var pause_location = await EvaluateAndCheck (eval_expr, 
-										debugger_test_loc, 
-										line, 
-										col, 
-										"run",
-										wait_for_event_fn: async (pause_location) => {
-											var locals = await GetProperties (pause_location ["callFrames"][0] ["callFrameId"].Value<string> ());
-											var evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "this.a");
-											CheckContentValue (evaluate, "1");
-											evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "this.b");
-											CheckContentValue (evaluate, "2");
-											evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "this.c");
-											CheckContentValue (evaluate, "3");
-										});
-			});
-		}
-		
-		
-		
+			=> await CheckInspectLocalsAtBreakpointSite (
+				"dotnet://debugger-test.dll/debugger-evaluate-test.cs", 18, 16,
+				"run",
+				"window.setTimeout(function() { invoke_static_method_async ('[debugger-test] DebuggerTests.EvaluateTestsClass:EvaluateLocals'); })",
+				wait_for_event_fn: async (pause_location) => {
+					var locals = await GetProperties (pause_location ["callFrames"][0] ["callFrameId"].Value<string> ());
+					var evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "this.a");
+					CheckContentValue (evaluate, "1");
+					evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "this.b");
+					CheckContentValue (evaluate, "2");
+					evaluate = await EvaluateOnCallFrame (pause_location ["callFrames"][0] ["callFrameId"].Value<string> (), "this.c");
+					CheckContentValue (evaluate, "3");
+				});
 
 		async Task<JObject> StepAndCheck (StepKind kind, string script_loc, int line, int column, string function_name,
 							Func<JObject, Task> wait_for_event_fn = null, Action<JToken> locals_fn = null, int times=1)
@@ -2023,6 +2099,65 @@ namespace DebuggerTests
 			return wait_res;
 		}
 
+		async Task CheckDelegate (JToken locals, string name, string className, string target)
+		{
+			var l = GetAndAssertObjectWithName (locals, name);
+			var val = l["value"];
+
+			await CheckDelegate (l, TDelegate (className, target), name);
+		}
+
+		async Task CheckDelegate (JToken actual_val, JToken exp_val, string label)
+		{
+			AssertEqual ("object", actual_val["type"]?.Value<string>(), $"{label}-type");
+			AssertEqual (exp_val ["className"]?.Value<string> (), actual_val ["className"]?.Value<string>(), $"{label}-className");
+
+			var actual_target = actual_val["description"]?.Value<string>();
+			Assert.True(actual_target != null, $"${label}-description");
+			var exp_target = exp_val["target"].Value<string>();
+
+			CheckDelegateTarget (actual_target, exp_target);
+
+			var del_props = await GetProperties(actual_val["objectId"]?.Value<string>());
+			AssertEqual (1, del_props.Count(), $"${label}-delegate-properties-count");
+
+			var obj = del_props.Where (jt => jt ["name"]?.Value<string> () == "Target").FirstOrDefault ();
+			Assert.True (obj != null, $"[{label}] Property named 'Target' found found in delegate properties");
+
+			AssertEqual("symbol", obj ["value"]?["type"]?.Value<string>(), $"{label}#Target#type");
+			CheckDelegateTarget(obj ["value"]?["value"]?.Value<string>(), exp_target);
+
+			return;
+
+			void CheckDelegateTarget(string actual_target, string exp_target)
+			{
+				var parts = exp_target.Split(new char[] { '|' }, StringSplitOptions.RemoveEmptyEntries);
+				if (parts.Length == 1) {
+					// not a generated method
+					AssertEqual(exp_target, actual_target, $"{label}-description");
+				} else {
+					bool prefix = actual_target.StartsWith(parts[0], StringComparison.Ordinal);
+					Assert.True(prefix, $"{label}-description, Expected target to start with '{parts[0]}'. Actual: '{actual_target}'");
+
+					var remaining = actual_target.Substring(parts[0].Length);
+					bool suffix = remaining.EndsWith(parts[1], StringComparison.Ordinal);
+					Assert.True(prefix, $"{label}-description, Expected target to end with '{parts[1]}'. Actual: '{remaining}'");
+				}
+			}
+		}
+
+		async Task CheckCustomType (JToken actual_val, JToken exp_val, string label)
+		{
+			var ctype = exp_val["__custom_type"].Value<string>();
+			switch (ctype) {
+				case "delegate":
+					await CheckDelegate (actual_val, exp_val, label);
+					break;
+				default:
+					throw new ArgumentException($"{ctype} not supported");
+			}
+		}
+
 		async Task CheckProps (JToken actual, object exp_o, string label, int num_fields=-1)
 		{
 			if (exp_o.GetType ().IsArray || exp_o is JArray) {
@@ -2032,7 +2167,7 @@ namespace DebuggerTests
 				}
 
 				var exp_v_arr = JArray.FromObject (exp_o);
-				Assert.Equal (exp_v_arr.Count, actual_arr.Count ());
+				AssertEqual (exp_v_arr.Count, actual_arr.Count (), $"{label}-count");
 
 				for (int i = 0; i < exp_v_arr.Count; i ++) {
 					var exp_i = exp_v_arr [i];
@@ -2078,6 +2213,11 @@ namespace DebuggerTests
 
 		async Task CheckValue (JToken actual_val, JToken exp_val, string label)
 		{
+			if (exp_val ["__custom_type"] != null) {
+				await CheckCustomType (actual_val, exp_val, label);
+				return;
+			}
+
 			if (exp_val ["type"] == null && actual_val ["objectId"] != null) {
 				var new_val = await GetProperties (actual_val ["objectId"].Value<string> ());
 				await CheckProps (new_val, exp_val, $"{label}-{actual_val["objectId"]?.Value<string>()}");
@@ -2085,6 +2225,13 @@ namespace DebuggerTests
 			}
 
 			foreach (var jp in exp_val.Values<JProperty> ()) {
+				if (jp.Value.Type == JTokenType.Object) {
+					var new_val = await GetProperties (actual_val ["objectId"].Value<string> ());
+					await CheckProps (new_val, jp.Value, $"{label}-{actual_val["objectId"]?.Value<string>()}");
+
+					continue;
+				}
+
 				var exp_val_str = jp.Value.Value<string> ();
 				bool null_or_empty_exp_val = String.IsNullOrEmpty (exp_val_str);
 
@@ -2237,6 +2384,12 @@ namespace DebuggerTests
 			return bp1_res;
 		}
 
+		void AssertEqual (object expected, object actual, string label)
+			=> Assert.True (expected?.Equals (actual),
+						$"[{label}]\n" +
+						$"Expected: {expected?.ToString()}\n" +
+						$"Actual:   {actual?.ToString()}\n");
+
 		//FIXME: um maybe we don't need to convert jobject right here!
 		static JObject TString (string value) =>
 			value == null
@@ -2266,6 +2419,19 @@ namespace DebuggerTests
 		static JObject TSymbol (string value)
 			=> JObject.FromObject (new { type = "symbol", value = @value, description = @value });
 
+		/*
+			For target names with generated method names like
+				`void <ActionTSignatureTest>b__11_0 (Math.GenericStruct<int[]>)`
+
+			.. pass target "as `target: "void <ActionTSignatureTest>|(Math.GenericStruct<int[]>)"`
+		*/
+		static JObject TDelegate(string className, string target)
+			=> JObject.FromObject(new {
+				__custom_type = "delegate",
+				className = className,
+				target = target
+			});
+
 		//TODO add tests covering basic stepping behavior as step in/out/over
 	}
 
diff --git a/sdks/wasm/debugger-test.cs b/sdks/wasm/debugger-test.cs
index 118320ae91c..be77e8c57e6 100644
--- a/sdks/wasm/debugger-test.cs
+++ b/sdks/wasm/debugger-test.cs
@@ -145,6 +145,130 @@ public class Math { //Only append content to this class as the test suite depend
 			Console.WriteLine ($"{c0}, {c1}");
 	}
 
+	public static int DelegatesSignatureTest ()
+	{
+		Func<Math, GenericStruct<GenericStruct<int[]>>, GenericStruct<bool[]>> fn_func = (m, gs) => new GenericStruct<bool[]>();
+		Func<Math, GenericStruct<GenericStruct<int[]>>, GenericStruct<bool[]>> fn_func_del = GenericStruct<int>.DelegateTargetForSignatureTest;
+		Func<Math, GenericStruct<GenericStruct<int[]>>, GenericStruct<bool[]>> fn_func_null = null;
+		Func<bool> fn_func_only_ret = () => { Console.WriteLine ($"hello"); return true; };
+		var fn_func_arr = new Func<Math, GenericStruct<GenericStruct<int[]>>, GenericStruct<bool[]>>[] { (m, gs) => new GenericStruct<bool[]>() };
+
+		Math.DelegateForSignatureTest fn_del = GenericStruct<int>.DelegateTargetForSignatureTest;
+		Math.DelegateForSignatureTest fn_del_l = (m, gs) => new GenericStruct<bool[]> { StringField = "fn_del_l#lambda" };
+		var fn_del_arr = new Math.DelegateForSignatureTest[] { GenericStruct<int>.DelegateTargetForSignatureTest, (m, gs) => new GenericStruct<bool[]> { StringField = "fn_del_arr#1#lambda" } };
+		var m_obj = new Math ();
+		Math.DelegateForSignatureTest fn_del_null = null;
+		var gs_gs = new GenericStruct<GenericStruct<int[]>>
+		{
+			List = new System.Collections.Generic.List<GenericStruct<int[]>> {
+				new GenericStruct<int[]> { StringField = "gs#List#0#StringField" },
+				new GenericStruct<int[]> { StringField = "gs#List#1#StringField" }
+			}
+		};
+
+		Math.DelegateWithVoidReturn fn_void_del = Math.DelegateTargetWithVoidReturn;
+		var fn_void_del_arr = new Math.DelegateWithVoidReturn[] { Math.DelegateTargetWithVoidReturn };
+		Math.DelegateWithVoidReturn fn_void_del_null = null;
+
+		var rets = new GenericStruct<bool[]>[] {
+			fn_func (m_obj, gs_gs),
+			fn_func_del (m_obj, gs_gs),
+			fn_del (m_obj, gs_gs),
+			fn_del_l (m_obj, gs_gs),
+			fn_del_arr[0] (m_obj, gs_gs),
+			fn_func_arr[0] (m_obj, gs_gs)
+		};
+
+		var gs = new GenericStruct<int[]>();
+		fn_void_del (gs);
+		fn_void_del_arr[0](gs);
+		fn_func_only_ret ();
+		foreach (var ret in rets) Console.WriteLine ($"ret: {ret}");
+		Console.WriteLine ($"- {gs_gs.List[0].StringField}");
+		Console.WriteLine ("DelegatesSignatureTest: Just a test message, ignore");
+		return 0;
+	}
+
+	public static int ActionTSignatureTest ()
+	{
+		Action<GenericStruct<int[]>> fn_action = (_) => { };
+		Action<GenericStruct<int[]>> fn_action_del = Math.DelegateTargetWithVoidReturn;
+		Action fn_action_bare = () => {};
+		Action<GenericStruct<int[]>> fn_action_null = null;
+		var fn_action_arr = new Action<GenericStruct<int[]>>[] {
+			(gs) => new GenericStruct<int[]>(),
+			Math.DelegateTargetWithVoidReturn,
+			null
+		};
+
+		var gs = new GenericStruct<int[]>();
+		fn_action (gs);
+		fn_action_del (gs);
+		fn_action_arr[0](gs);
+		fn_action_bare ();
+		Console.WriteLine ("DelegatesSignatureTest: Just a test message, ignore");
+		return 0;
+	}
+
+	public static int NestedDelegatesTest ()
+	{
+		Func<Func<int, bool>, bool> fn_func = (_) => { return true; };
+		Func<Func<int, bool>, bool> fn_func_null = null;
+		var fn_func_arr = new Func<Func<int, bool>, bool>[] { (gs) => { return true; } };
+
+		var fn_del_arr = new Func<Func<int, bool>, bool>[] { DelegateTargetForNestedFunc<Func<int, bool>> };
+		var m_obj = new Math ();
+		Func<Func<int, bool>, bool> fn_del_null = null;
+		Func<int, bool> fs = (i) => i == 0;
+		fn_func (fs);
+		fn_del_arr[0](fs);
+		fn_func_arr[0](fs);
+		Console.WriteLine ("DelegatesSignatureTest: Just a test message, ignore");
+		return 0;
+	}
+
+	public static void DelegatesAsMethodArgsTest ()
+	{
+		var _dst_arr = new DelegateForSignatureTest[] {
+			GenericStruct<int>.DelegateTargetForSignatureTest,
+			(m, gs) => new GenericStruct<bool[]> ()
+		};
+		Func<char[], bool> _fn_func = (cs) => cs.Length == 0;
+		Action<GenericStruct<int>[]> _fn_action = (gss) => { };
+
+		new Math ().MethodWithDelegateArgs (_dst_arr, _fn_func, _fn_action);
+	}
+
+	void MethodWithDelegateArgs (Math.DelegateForSignatureTest[] dst_arr, Func<char[], bool> fn_func,
+					Action<GenericStruct<int>[]> fn_action)
+	{
+		Console.WriteLine ($"Placeholder for breakpoint");
+	}
+
+	public static async System.Threading.Tasks.Task MethodWithDelegatesAsyncTest ()
+	{
+		await new Math ().MethodWithDelegatesAsync ();
+	}
+
+	async System.Threading.Tasks.Task MethodWithDelegatesAsync ()
+	{
+		var _dst_arr = new DelegateForSignatureTest[] {
+			GenericStruct<int>.DelegateTargetForSignatureTest,
+			(m, gs) => new GenericStruct<bool[]> ()
+		};
+		Func<char[], bool> _fn_func = (cs) => cs.Length == 0;
+		Action<GenericStruct<int>[]> _fn_action = (gss) => { };
+
+		Console.WriteLine ($"Placeholder for breakpoint");
+		await System.Threading.Tasks.Task.CompletedTask;
+	}
+
+	delegate void DelegateWithVoidReturn (GenericStruct<int[]> gs);
+	static void DelegateTargetWithVoidReturn (GenericStruct<int[]> gs) { }
+
+	delegate GenericStruct<bool[]> DelegateForSignatureTest (Math m, GenericStruct<GenericStruct<int[]>> gs);
+	static bool DelegateTargetForNestedFunc<T>(T arg) => true;
+
 	struct SimpleStruct
 	{
 		public DateTime dt;
@@ -155,6 +279,9 @@ public class Math { //Only append content to this class as the test suite depend
 	{
 		public System.Collections.Generic.List<T> List;
 		public string StringField;
+
+		public static GenericStruct<bool[]> DelegateTargetForSignatureTest (Math m, GenericStruct<GenericStruct<T[]>> gs)
+			=> new GenericStruct<bool[]> ();
 	}
 
 }
diff --git a/sdks/wasm/src/library_mono.js b/sdks/wasm/src/library_mono.js
index 250614115a5..538112d7c1a 100644
--- a/sdks/wasm/src/library_mono.js
+++ b/sdks/wasm/src/library_mono.js
@@ -437,7 +437,7 @@ var MonoSupportLib = {
 		{
 			// Fix up generic names like Foo`2<int, string> to Foo<int, string>
 			// and nested class names like Foo/Bar to Foo.Bar
-			return className.replace('/', '.').replace(/`\d+/, '');
+			return className.replace(/\//g, '.').replace(/`\d+/g, '');
 		},
 	},
 
@@ -618,20 +618,57 @@ var MonoSupportLib = {
 		});
 	},
 
-	mono_wasm_add_func_var: function(className, objectId) {
+	/*
+	 * @className, and @targetName are in the following format:
+	 *
+	 *  <ret_type>:[<comma separated list of arg types>]:<method name>
+	 */
+	mono_wasm_add_func_var: function (className, targetName, objectId) {
 		if (objectId == 0) {
-			MONO.mono_wasm_add_null_var (className);
+			MONO.mono_wasm_add_null_var (
+				MONO._mono_csharp_fixup_class_name (Module.UTF8ToString (className)));
 			return;
 		}
 
-		fixed_class_name = MONO._mono_csharp_fixup_class_name(Module.UTF8ToString (className));
-		MONO.var_info.push({
-			value: {
-				type: "function",
-				description: fixed_class_name,
-				objectId: "dotnet:object:"+ objectId,
-			}
-		});
+		function args_to_sig (args_str) {
+			var parts = args_str.split (":");
+			// TODO: min length = 3?
+			parts = parts.map (a => MONO._mono_csharp_fixup_class_name (a));
+
+			// method name at the end
+			var method_name = parts.pop ();
+
+			// ret type at the beginning
+			var ret_sig = parts [0];
+			var args_sig = parts.splice (1).join (', ');
+			return `${ret_sig} ${method_name} (${args_sig})`;
+		}
+
+		var tgt_sig;
+		if (targetName != 0)
+			tgt_sig = args_to_sig (Module.UTF8ToString (targetName));
+
+		var type_name = MONO._mono_csharp_fixup_class_name (Module.UTF8ToString (className));
+
+		if (objectId == -1) {
+			// Target property
+			MONO.var_info.push ({
+				value: {
+					type: "symbol",
+					value: tgt_sig,
+					description: tgt_sig,
+				}
+			});
+		} else {
+			MONO.var_info.push ({
+				value: {
+					type: "object",
+					className: type_name,
+					description: tgt_sig,
+					objectId: "dotnet:object:" + objectId,
+				}
+			});
+		}
 	},
 
 	mono_wasm_add_frame: function(il, method, name) {