2 files changed, 67 insertions, 20 deletions

diff --git a/cli/tests/unit/timers_test.ts b/cli/tests/unit/timers_test.ts
index e315d018a..55bc11f76 100644
--- a/cli/tests/unit/timers_test.ts
+++ b/cli/tests/unit/timers_test.ts
@@ -7,10 +7,51 @@ import {
   unitTest,
 } from "./test_util.ts";
 
-function waitForMs(ms: number): Promise<number> {
+function waitForMs(ms: number): Promise<void> {
   return new Promise((resolve): number => setTimeout(resolve, ms));
 }
 
+unitTest(async function functionParameterBindingSuccess(): Promise<void> {
+  const promise = deferred();
+  let count = 0;
+
+  const nullProto = (newCount: number): void => {
+    count = newCount;
+    promise.resolve();
+  };
+
+  Reflect.setPrototypeOf(nullProto, null);
+
+  setTimeout(nullProto, 500, 1);
+  await promise;
+  // count should be reassigned
+  assertEquals(count, 1);
+});
+
+unitTest(async function stringifyAndEvalNonFunctions(): Promise<void> {
+  // eval can only access global scope
+  const global = globalThis as unknown as {
+    globalPromise: ReturnType<typeof deferred>;
+    globalCount: number;
+  };
+  global.globalPromise = deferred();
+  global.globalCount = 0;
+
+  const notAFunction =
+    "globalThis.globalCount++; globalThis.globalPromise.resolve();" as unknown as () =>
+      void;
+
+  setTimeout(notAFunction, 500);
+
+  await global.globalPromise;
+
+  // count should be incremented
+  assertEquals(global.globalCount, 1);
+
+  Reflect.deleteProperty(global, "globalPromise");
+  Reflect.deleteProperty(global, "globalCount");
+});
+
 unitTest(async function timeoutSuccess(): Promise<void> {
   const promise = deferred();
   let count = 0;
diff --git a/runtime/js/11_timers.js b/runtime/js/11_timers.js
index 5a59844a3..166694358 100644
--- a/runtime/js/11_timers.js
+++ b/runtime/js/11_timers.js
@@ -274,7 +274,7 @@
   }
 
   const { console } = globalThis;
-  const OriginalDate = Date;
+  const OriginalDateNow = Date.now;
 
   // Timeout values > TIMEOUT_MAX are set to 1.
   const TIMEOUT_MAX = 2 ** 31 - 1;
@@ -333,7 +333,7 @@
   }
 
   function prepareReadyTimers() {
-    const now = OriginalDate.now();
+    const now = OriginalDateNow();
     // Bail out if we're not expecting the global timer to fire.
     if (globalTimeoutDue === null || pendingEvents > 0) {
       return;
@@ -409,7 +409,7 @@
         const nextDueNode = dueTree.min();
         setOrClearGlobalTimeout(
           nextDueNode && nextDueNode.due,
-          OriginalDate.now(),
+          OriginalDateNow(),
         );
       }
     } else {
@@ -434,14 +434,18 @@
     } else {
       // Interval timer: compute when timer was supposed to fire next.
       // However make sure to never schedule the next interval in the past.
-      const now = OriginalDate.now();
+      const now = OriginalDateNow();
       timer.due = Math.max(now, timer.due + timer.delay);
       schedule(timer, now);
     }
     // Call the user callback. Intermediate assignment is to avoid leaking `this`
     // to it, while also keeping the stack trace neat when it shows up in there.
     const callback = timer.callback;
-    callback();
+    if ("function" === typeof callback) {
+      callback();
+    } else {
+      eval(callback);
+    }
   }
 
   function checkThis(thisArg) {
@@ -450,24 +454,26 @@
     }
   }
 
-  function checkBigInt(n) {
-    if (typeof n === "bigint") {
-      throw new TypeError("Cannot convert a BigInt value to a number");
-    }
-  }
-
   function setTimer(
     cb,
     delay,
     args,
     repeat,
   ) {
-    // Bind `args` to the callback and bind `this` to globalThis(global).
-    const callback = cb.bind(globalThis, ...args);
+    // If the callack is a function, bind `args` to the callback and bind `this` to globalThis(global).
+    // otherwise call `String` on it, and `eval` it on calls; do not pass variardic args to the string
+    let callback;
+
+    if ("function" === typeof cb) {
+      callback = Function.prototype.bind.call(cb, globalThis, ...args);
+    } else {
+      callback = String(cb);
+      args = []; // args are ignored
+    }
     // In the browser, the delay value must be coercible to an integer between 0
     // and INT32_MAX. Any other value will cause the timer to fire immediately.
     // We emulate this behavior.
-    const now = OriginalDate.now();
+    const now = OriginalDateNow();
     if (delay > TIMEOUT_MAX) {
       console.warn(
         `${delay} does not fit into` +
@@ -500,7 +506,7 @@
     delay = 0,
     ...args
   ) {
-    checkBigInt(delay);
+    delay >>>= 0;
     checkThis(this);
     return setTimer(cb, delay, args, false);
   }
@@ -510,13 +516,13 @@
     delay = 0,
     ...args
   ) {
-    checkBigInt(delay);
+    delay >>>= 0;
     checkThis(this);
     return setTimer(cb, delay, args, true);
   }
 
   function clearTimer(id) {
-    id = Number(id);
+    id >>>= 0;
     const timer = idMap.get(id);
     if (timer === undefined) {
       // Timer doesn't exist any more or never existed. This is not an error.
@@ -528,7 +534,7 @@
   }
 
   function clearTimeout(id = 0) {
-    checkBigInt(id);
+    id >>>= 0;
     if (id === 0) {
       return;
     }
@@ -536,7 +542,7 @@
   }
 
   function clearInterval(id = 0) {
-    checkBigInt(id);
+    id >>>= 0;
     if (id === 0) {
       return;
     }