feat(event-loop): support passing a code string to setTimeout as the callback function

Author: Xmader

python/pythonmonkey/builtin_modules/timers.js

@@ -21,8 +21,9 @@ const {
  */
 function setTimeout(handler, delayMs = 0, ...args) {
   // Ensure the first parameter is a function
+  // We support passing a `code` string to `setTimeout` as the callback function
   if (typeof handler !== "function") {
-    throw new TypeError("The first parameter to setTimeout() is not a function")
+    handler = new Function(handler)
   }
 
   // `setTimeout` allows passing additional arguments to the callback, as spec-ed

tests/python/test_event_loop.py

@@ -48,15 +48,13 @@ def to_raise(msg):
         pm.eval("clearTimeout(undefined)")
         pm.eval("clearTimeout()")
 
-        # should throw a TypeError when the first parameter to `setTimeout` is not a function
-        with pytest.raises(pm.SpiderMonkeyError, match="TypeError: The first parameter to setTimeout\\(\\) is not a function"):
-            pm.eval("setTimeout()")
-        with pytest.raises(pm.SpiderMonkeyError, match="TypeError: The first parameter to setTimeout\\(\\) is not a function"):
-            pm.eval("setTimeout(undefined)")
-        with pytest.raises(pm.SpiderMonkeyError, match="TypeError: The first parameter to setTimeout\\(\\) is not a function"):
-            pm.eval("setTimeout(1)")
-        with pytest.raises(pm.SpiderMonkeyError, match="TypeError: The first parameter to setTimeout\\(\\) is not a function"):
-            pm.eval("setTimeout('a', 100)")
+        # passing a `code` string to `setTimeout` as the callback function
+        assert "code string" == await pm.eval("""
+        new Promise((resolve) => {
+            globalThis._resolve = resolve
+            setTimeout("globalThis._resolve('code string'); delete globalThis._resolve", 100)
+        })
+        """)
 
         # making sure the async_fn is run
         return True