fix(ext/timers): create primordial eval (#15110)

cli/tests/unit/timers_test.ts

@@ -84,6 +84,27 @@ Deno.test(async function timeoutEvalNoScopeLeak() {
   Reflect.deleteProperty(global, "globalPromise");
 });
 
+Deno.test(async function evalPrimordial() {
+  const global = globalThis as unknown as {
+    globalPromise: ReturnType<typeof deferred>;
+  };
+  global.globalPromise = deferred();
+  const originalEval = globalThis.eval;
+  let wasCalled = false;
+  globalThis.eval = (argument) => {
+    wasCalled = true;
+    return originalEval(argument);
+  };
+  setTimeout(
+    "globalThis.globalPromise.resolve();" as unknown as () => void,
+    0,
+  );
+  await global.globalPromise;
+  assert(!wasCalled);
+  Reflect.deleteProperty(global, "globalPromise");
+  globalThis.eval = originalEval;
+});
+
 Deno.test(async function timeoutArgs() {
   const promise = deferred();
   const arg = 1;

core/00_primordials.js

@@ -468,6 +468,11 @@
     queueMicrotask = value;
   };
 
+  // Renaming from `eval` is necessary because otherwise it would perform direct
+  // evaluation, allowing user-land access to local variables.
+  // This is because the identifier `eval` is somewhat treated as a keyword
+  primordials.indirectEval = eval;
+
   ObjectSetPrototypeOf(primordials, null);
   ObjectFreeze(primordials);
 

ext/web/02_timers.js

@@ -21,6 +21,7 @@
     SafeArrayIterator,
     SymbolFor,
     TypeError,
+    indirectEval,
   } = window.__bootstrap.primordials;
   const { webidl } = window.__bootstrap;
   const { reportException } = window.__bootstrap.event;
@@ -155,9 +156,7 @@
             reportException(error);
           }
         } else {
-          // TODO(@andreubotella): eval doesn't seem to have a primordial, but
+          indirectEval(callback);
-          // it can be redefined in the global scope.
-          (0, eval)(callback);
         }
 
         if (repeat) {