From 73bf45e64bc8899a8f53b06e3727ea8733817473 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Tue, 16 Feb 2021 14:13:31 +0100
Subject: [PATCH] Support `Map` and `Set`, with `postMessage`, when workers are
 disabled

The `LoopbackPort` currently doesn't support `Map` and `Set`, which it should since the "structured clone algorithm" used in browsers does support both of them; please see https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API/Structured_clone_algorithm#supported_types
---
 src/display/api.js | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/src/display/api.js b/src/display/api.js
index c8c5c025b..86b564e48 100644
--- a/src/display/api.js
+++ b/src/display/api.js
@@ -1656,8 +1656,24 @@ class LoopbackPort {
         cloned.set(value, result);
         return result;
       }
+      if (value instanceof Map) {
+        result = new Map();
+        cloned.set(value, result); // Adding to cache now for cyclic references.
+        for (const [key, val] of value) {
+          result.set(key, cloneValue(val));
+        }
+        return result;
+      }
+      if (value instanceof Set) {
+        result = new Set();
+        cloned.set(value, result); // Adding to cache now for cyclic references.
+        for (const val of value) {
+          result.add(cloneValue(val));
+        }
+        return result;
+      }
       result = Array.isArray(value) ? [] : {};
-      cloned.set(value, result); // adding to cache now for cyclic references
+      cloned.set(value, result); // Adding to cache now for cyclic references.
       // Cloning all value and object properties, however ignoring properties
       // defined via getter.
       for (const i in value) {