Type check (breaks test)'

Author: elliette

dwds/lib/src/services/expression_compiler_service.dart

@@ -29,12 +29,22 @@ class _Compiler {
   /// response stream.
   Future<Map<String, Object>> _send(Map<String, Object> request) async {
     _sendPort.send(request);
-    return await _responseQueue.hasNext
-        ? Map<String, Object>.from(await _responseQueue.next)
-        : {
+    if (!await _responseQueue.hasNext) {
+      return {
             'succeeded': false,
             'errors': ['compilation service response stream closed'],
           };
+    }
+    final next = await _responseQueue.next;
+    if (next is! Map<String, Object>) {
+      return {
+        'succeeded': false,
+        'errors': [
+          'received invalid result from expression compiler worker: $next'
+        ],
+      };
+    }
+    return next;
   }
 
   /// Starts expression compilation service.