feat: await promises in WebView JS eval via token-based poll loop

[gmegidish]

No description provided.

[coderabbitai]

Walkthrough

WebViewAgent's JavaScript evaluation method is refactored to support async expressions. A per-process evaluation token counter is introduced. The evaluateExpression method now injects JavaScript that wraps the expression in promise-aware code and stores the resolved result as JSON into a window slot identified by the token. The Java side then polls for this stored result with a 10-second deadline. The helper methods buildEvalScript and buildPollScript are added to construct the injected scripts and handle result retrieval and clearing.

🚥 Pre-merge checks | ✅ 3 | ❌ 2

❌ Failed checks (1 warning, 1 inconclusive)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 33.33% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.
Description check	❓ Inconclusive	No pull request description was provided by the author, making it impossible to assess relatedness to the changeset.	Add a description explaining the motivation for async promise support, how it improves the WebView evaluation flow, and any relevant implementation details or testing notes.

✅ Passed checks (3 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately describes the main change: implementing async JavaScript promise support in WebView evaluation through token-based polling.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch feat/webview-async-eval-promise

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[coderabbitai]

Actionable comments posted: 2

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@agents/android/java/WebViewAgent.java`:
- Around line 91-97: evaluateExpression currently only treats
JSONTokener(raw).nextValue() as valid when it's a String, which causes timeouts
if the bridge returns an unquoted object/array or if JSON.stringify inside
buildEvalScript throws; update evaluateExpression to accept JSONObject/JSONArray
(and any non-String tokenized result) by converting tokenized.toString() (or raw
when tokenized is not a String) into outcomeJson so the poll succeeds, and also
harden buildEvalScript so its Promise then/catch handlers each wrap
JSON.stringify in try/catch and always assign a string value to
window.__mwEval[token] (on both success and failure) to avoid leaving the slot
unset; reference evaluateExpression, buildPollScript, buildEvalScript,
AndroidBridge.evalJs, and JSONTokener in the change so you locate the spots to
modify.
- Around line 123-136: In WebViewAgent.buildEvalScript the injected body can
fail to parse before the outer try/catch and JSON.stringify errors inside the
then() success handler can escape the rejection handler, leaving
window.__mwEval[token] unwritten; to fix, compile the user body inside the
script try block (e.g., create the function via new Function(...)/Function.apply
inside the try so SyntaxError is caught) and make setting window.__mwEval[token]
resilient by wrapping JSON.stringify (or the assignment) in its own try/catch in
both fulfillment and rejection paths, and/or replace .then(success, failure)
with .then(success).catch(failure) so exceptions in the success handler are
forwarded to the common failure handler; update references to token and
window.__mwEval in buildEvalScript accordingly so every code path writes a JSON
string into window.__mwEval[token].

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 11f28dda-5589-4bba-ac77-a15f79ed2546

📥 Commits

Reviewing files that changed from the base of the PR and between e61ff5a and 367e707.

📒 Files selected for processing (1)

• agents/android/java/WebViewAgent.java

[coderabbitai]

Caution

Some comments are outside the diff and can’t be posted inline due to platform limitations.

⚠️ Outside diff range comments (1)

agents/ios/bridge.m (1)

132-132: ⚠️ Potential issue | 🟡 Minor | ⚡ Quick win

Update timeout message to reflect the actual API in use.

The error message still references "evaluateJavaScript" but the code now uses callAsyncJavaScript.

📝 Proposed fix

-        return @{@"__error": @"evaluateJavaScript timed out"};
+        return @{@"__error": @"JavaScript evaluation timed out"};

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@agents/ios/bridge.m` at line 132, The timeout error message is stale — update
the returned error string (the @{@"__error": ...} return) so it references the
current API callAsyncJavaScript instead of evaluateJavaScript; locate the return
in the bridge.m function that returns @{@"__error": @"evaluateJavaScript timed
out"} and change the message to something like @"callAsyncJavaScript timed out"
(or a similarly accurate phrasing).

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Outside diff comments:
In `@agents/ios/bridge.m`:
- Line 132: The timeout error message is stale — update the returned error
string (the @{@"__error": ...} return) so it references the current API
callAsyncJavaScript instead of evaluateJavaScript; locate the return in the
bridge.m function that returns @{@"__error": @"evaluateJavaScript timed out"}
and change the message to something like @"callAsyncJavaScript timed out" (or a
similarly accurate phrasing).

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 60564526-3d1c-4469-9eb8-f69d01977c8b

📥 Commits

Reviewing files that changed from the base of the PR and between 367e707 and 3df9efe.

📒 Files selected for processing (3)

• agents/android/java/WebViewAgent.java
• agents/ios/bridge.m
• go.mod

🚧 Files skipped from review as they are similar to previous changes (1)

• agents/android/java/WebViewAgent.java