feat: improve execution state management and enhance message handling in iframe communication

Author: frontegg-david

apps/browser-demo/src/App.tsx

@@ -35,12 +35,16 @@ export function App() {
 
   const { startCapture, stopCapture } = useConsoleCapture();
 
-  const handleRun = useCallback(async () => {
-    if (!ready || running) return;
-    setRunning(true);
+  const resetExecutionState = useCallback(() => {
     setResult(null);
     setConsoleEntries([]);
     setStats(null);
+  }, []);
+
+  const handleRun = useCallback(async () => {
+    if (!ready || running) return;
+    setRunning(true);
+    resetExecutionState();
 
     try {
       startCapture();
@@ -65,18 +69,24 @@ export function App() {
       });
       setStats(zeroStats);
     } finally {
-      const captured = stopCapture();
+      let captured: ConsoleEntry[] = [];
+      try {
+        captured = stopCapture();
+      } catch (_err) {
+        /* stopCapture failure should not block UI reset */
+      }
       setConsoleEntries(captured);
       setRunning(false);
     }
-  }, [ready, running, code, run, startCapture, stopCapture]);
+  }, [ready, running, code, run, startCapture, stopCapture, resetExecutionState]);
 
-  const handleExampleSelect = useCallback((exampleCode: string) => {
-    setCode(exampleCode);
-    setResult(null);
-    setConsoleEntries([]);
-    setStats(null);
-  }, []);
+  const handleExampleSelect = useCallback(
+    (exampleCode: string) => {
+      setCode(exampleCode);
+      resetExecutionState();
+    },
+    [resetExecutionState],
+  );
 
   return (
     <div className="app">

libs/browser/e2e/fixtures/debug-inner.html

@@ -135,7 +135,7 @@
         window.addEventListener('message', function (event) {
           var data = event.data;
           if (!data || data.__enclave_msg__ !== true) return;
-          if (data.requestId && data.requestId !== requestId) return;
+          if (data.requestId !== requestId) return;
 
           if (data.type === 'tool-response') {
             var pending = pendingToolCalls[data.callId];
@@ -407,7 +407,6 @@
         // Memory-safe prototype patches
         (function () {
           var ml = 1048576;
-          if (ml <= 0) return;
           var totalTracked = 0;
           function track(bytes) {
             totalTracked += bytes;
@@ -539,8 +538,6 @@
           'indexedDB',
           'caches',
           'navigator',
-          'location',
-          'document',
           'open',
           'close',
           'alert',
@@ -692,6 +689,9 @@
         // Execute User Code
         // ============================================================
         (async function () {
+          // Shadow non-deletable browser globals so user code sees undefined
+          var document = undefined;
+
           try {
             // The transformed code defines __ag_main as a function declaration.
             // We embed it directly — CSP 'unsafe-inline' allows inline scripts

libs/browser/e2e/fixtures/debug-inner2.html

@@ -135,7 +135,7 @@
         window.addEventListener('message', function (event) {
           var data = event.data;
           if (!data || data.__enclave_msg__ !== true) return;
-          if (data.requestId && data.requestId !== requestId) return;
+          if (data.requestId !== requestId) return;
 
           if (data.type === 'tool-response') {
             var pending = pendingToolCalls[data.callId];
@@ -407,7 +407,6 @@
         // Memory-safe prototype patches
         (function () {
           var ml = 1048576;
-          if (ml <= 0) return;
           var totalTracked = 0;
           function track(bytes) {
             totalTracked += bytes;
@@ -539,8 +538,6 @@
           'indexedDB',
           'caches',
           'navigator',
-          'location',
-          'document',
           'open',
           'close',
           'alert',
@@ -693,6 +690,9 @@
         // Execute User Code
         // ============================================================
         (async function () {
+          // Shadow non-deletable browser globals so user code sees undefined
+          var document = undefined;
+
           try {
             // The transformed code defines __ag_main as a function declaration.
             // We embed it directly — CSP 'unsafe-inline' allows inline scripts

libs/browser/e2e/fixtures/debug-outer.html

@@ -152,7 +152,7 @@ function generateInnerIframeScript(userCode: string, config: SerializedIframeCon
   window.addEventListener('message', function(event) {
     var data = event.data;
     if (!data || data.__enclave_msg__ !== true) return;
-    if (data.requestId && data.requestId !== requestId) return;
+    if (data.requestId !== requestId) return;
 
     if (data.type === 'tool-response') {
       var pending = pendingToolCalls[data.callId];
@@ -660,7 +660,9 @@ function generateUserCodeExecution(userCode: string): string {
   // The user code has already been transformed by @enclave-vm/ast
   // and contains __ag_main() function definition.
   // We embed it directly - it runs in the same script context.
-  return userCode;
+  // Escape closing script tags to prevent HTML parser breakout
+  // when embedded via buildIframeHtml's <script>${content}</script>
+  return userCode.replace(/<\//g, '<\\/');
 }
 
 /**

libs/browser/src/adapters/inner-iframe-bootstrap.ts

@@ -197,7 +197,7 @@ function generateOuterIframeScript(options: OuterIframeBootstrapOptions): string
 
     var fromInner = (innerFrame && event.source === innerFrame.contentWindow);
     var fromHost = (event.source === window.parent);
-    if (data.requestId && data.requestId !== requestId) return;
+    if (data.requestId !== requestId) return;
 
     // Messages from inner iframe (tool-call, result, console)
     if (data.type === 'tool-call') {

libs/browser/src/adapters/outer-iframe-bootstrap.ts

@@ -215,6 +215,14 @@ export class BrowserEnclave {
 
     // Create validator
     const presetName: AstPreset = options.preset ?? 'agentscript';
+
+    if (this.customGlobalNames.length > 0 && presetName !== 'agentscript') {
+      throw new Error(
+        "Custom globals are only supported with the 'agentscript' preset. " +
+          'Remove globals or switch to preset: "agentscript".',
+      );
+    }
+
     this.validator = this.createValidator(presetName, customAllowedGlobals);
 
     // Config flags