Fixes #33

[cmtonkinson]

This was a tough one. The naive fix, and my initial thought, was to just make the wrapper async/await the result. Turns out that broke nearly everything.

isolated-vm deadlocks when called inside an async function which itself is being awaited from another async. I tried various "simple" fixes and kept breaking synchronous tool call tests.

That mean a dual-path:

• For IIFE, use .then() to avoid the extra nested await
• With an explicit return, use the await wrapper ... and I have no idea how to solve this without literally parsing the code, which super sucks.

This should be considered a temporary hack until we can get to the bottom of a Real Fix(TM).

---

Summary by cubic

Fixes #33 by correctly returning results from async IIFEs and top‑level await in callToolChain, while keeping synchronous tool calls stable. Uses a dual-path wrapper to avoid isolated-vm deadlocks and premature Promise serialization.

• Bug Fixes
  • Resolve async results via ivm.Reference callbacks, ensuring Promises settle before JSON serialization.
  • Detect pure-expression vs statement code to choose between a .then() expression wrapper or an async/await statement wrapper.
  • Updated docs to note that await on tools is supported; added regression tests and jest.config.cjs using ts-jest.

^{Written for commit 6ce36e4. Summary will update on new commits.}

[cubic-dev-ai]

4 issues found across 3 files

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="typescript-library/src/code_mode_utcp_client.ts">

<violation number="1" location="typescript-library/src/code_mode_utcp_client.ts:262">
P2: Heuristic expression/statement detection can misclassify valid expressions, causing the statement wrapper to run and silently return undefined.</violation>

<violation number="2" location="typescript-library/src/code_mode_utcp_client.ts:287">
P2: Expression-mode wrapping breaks empty/whitespace input by generating invalid syntax (`var __userResult = ;`), regressing prior no-op behavior.</violation>

<violation number="3" location="typescript-library/src/code_mode_utcp_client.ts:319">
P1: `callToolChain` can hang indefinitely because it awaits `resultPromise` without a timeout after `script.run` timeout has already elapsed scope.</violation>
</file>

<file name="typescript-library/tests/code_mode_utcp_client.test.ts">

<violation number="1" location="typescript-library/tests/code_mode_utcp_client.test.ts:599">
P2: Regression test claims top-level await coverage but never uses `await`, so it does not validate the intended behavior.</violation>
</file>

---

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[cubic-dev-ai]

P1: callToolChain can hang indefinitely because it awaits resultPromise without a timeout after script.run timeout has already elapsed scope.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At typescript-library/src/code_mode_utcp_client.ts, line 319:

<comment>`callToolChain` can hang indefinitely because it awaits `resultPromise` without a timeout after `script.run` timeout has already elapsed scope.</comment>

<file context>
@@ -204,25 +205,124 @@ ${interfaces.join('\n\n')}`;
+
+      // Run the script (starts the async IIFE); then await the callback-based promise.
+      await script.run(context, { timeout });
+      const resultJson = await resultPromise;
+
       // Parse the result from JSON
</file context>

[cubic-dev-ai]

P2: Heuristic expression/statement detection can misclassify valid expressions, causing the statement wrapper to run and silently return undefined.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At typescript-library/src/code_mode_utcp_client.ts, line 262:

<comment>Heuristic expression/statement detection can misclassify valid expressions, causing the statement wrapper to run and silently return undefined.</comment>

<file context>
@@ -204,25 +205,124 @@ ${interfaces.join('\n\n')}`;
+          if (ch === ')' || ch === ']' || ch === '}') { depth--; i++; continue; }
+          if (depth === 0) {
+            for (const kw of stmtKeywords) {
+              if (s.startsWith(kw, i)) return false;
+            }
+          }
</file context>

[cubic-dev-ai]

P2: Expression-mode wrapping breaks empty/whitespace input by generating invalid syntax (var __userResult = ;), regressing prior no-op behavior.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At typescript-library/src/code_mode_utcp_client.ts, line 287:

<comment>Expression-mode wrapping breaks empty/whitespace input by generating invalid syntax (`var __userResult = ;`), regressing prior no-op behavior.</comment>

<file context>
@@ -204,25 +205,124 @@ ${interfaces.join('\n\n')}`;
+        wrappedCode = `
+          (async function() {
+            try {
+              var __userResult = ${code};
+              if (__userResult && typeof __userResult.then === 'function') {
+                __userResult.then(function(v) {
</file context>

Suggested change

	var __userResult = ${code};
	var __userResult = ${code.trim() ? code : 'undefined'};

[cubic-dev-ai]

P2: Regression test claims top-level await coverage but never uses await, so it does not validate the intended behavior.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At typescript-library/tests/code_mode_utcp_client.test.ts, line 599:

<comment>Regression test claims top-level await coverage but never uses `await`, so it does not validate the intended behavior.</comment>

<file context>
@@ -580,6 +580,48 @@ describe('CodeModeUtcpClient', () => {
+    expect(result.operation).toBe('addition');
+  });
+
+  test('should support top-level await syntax (issue #33)', async () => {
+    // Top-level await works because the wrapper is now an async function.
+    const code = `
</file context>

[h3xxit]

Yeah I was also having some issues with the whole async stuff and I'm not a TS expert. I'm not sure I understand why this is temporary fix only.

Do you think it would be easier to just remove the result altogher and standardize it so it only supports returning via console.log?