fix(jsx): preserve context when using await before html helper by kaigritun · Pull Request #4662 · honojs/hono

kaigritun · 2026-02-05T09:30:11Z

Summary

When an async component used await before returning html\...`with children that access context viauseContext, the context was being popped synchronously in the finally` block before the Promise resolved.

Root Cause

In src/jsx/context.ts, the createContext function uses a finally block to pop the context value after rendering children. However, when .toString() returns a Promise (async components), the finally block executes immediately before the Promise resolves, causing descendant components to lose access to the context.

Before (broken)

try {
  string = props.children?.toString()
} finally {
  values.pop() // Executes immediately, even if string is a Promise!
}

After (fixed)

try {
  string = props.children?.toString()
} catch (e) {
  values.pop()
  throw e
}

if (string instanceof Promise) {
  return string.then(
    (resString) => {
      values.pop() // Pop after Promise resolves
      return raw(resString, ...)
    },
    (e) => {
      values.pop() // Pop on rejection too
      throw e
    }
  )
} else {
  values.pop() // Sync case: pop immediately
  return raw(string)
}

Reproduction

const Parent = async (props: { children?: any }) => {
  await new Promise((r) => setTimeout(r, 1000));
  return html\`<div>${props.children}</div>\`;
};

const Child = () => {
  const c = useRequestContext(); // Error: RequestContext is not provided
  return <div>hoge</div>;
};

// This now works correctly
<Parent>
  <Child />
</Parent>

Testing

Added 2 regression tests for the specific scenario
All 1636 existing JSX tests pass

When an async component used await before returning html with children, the context was being popped synchronously in the finally block before the Promise resolved. This caused children to lose access to the context. The fix delays the pop() until the Promise resolves (or rejects), ensuring context remains available throughout the async component's execution. Fixes honojs#4582

codecov · 2026-02-05T23:14:48Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.43%. Comparing base (f7d272a) to head (ebde4eb).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #4662   +/-   ##
=======================================
  Coverage   91.43%   91.43%           
=======================================
  Files         173      173           
  Lines       11373    11377    +4     
  Branches     3296     3298    +2     
=======================================
+ Hits        10399    10403    +4     
  Misses        973      973           
  Partials        1        1

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usualoma · 2026-02-06T00:26:51Z

Hi @kaigritun

Thank you for creating the pull request. It's a huge help!

I believe the proposed changes will fix the issue correctly. I'd like to reduce the number of values.pop() statements, so would it be okay to change it as follows? I think we can merge it then.

diff --git i/src/jsx/context.ts w/src/jsx/context.ts
index be4a8a99..dd32d7d3 100644
--- i/src/jsx/context.ts
+++ w/src/jsx/context.ts
@@ -30,16 +30,11 @@ export const createContext = <T>(defaultValue: T): Context<T> => {
     }
 
     if (string instanceof Promise) {
-      return string.then(
-        (resString) => {
+      return string
+        .then((resString) => raw(resString, (resString as HtmlEscapedString).callbacks))
+        .finally(() => {
           values.pop()
-          return raw(resString, (resString as HtmlEscapedString).callbacks)
-        },
-        (e) => {
-          values.pop()
-          throw e
-        }
-      )
+        })
     } else {
       values.pop()
       return raw(string)

kaigritun · 2026-02-06T01:25:03Z

Refactored to use .finally() as suggested. The cleanup now happens in one place:

return string
  .finally(() => values.pop())
  .then((resString) => raw(resString, ...))

This removes the duplicate values.pop() calls from both the resolve and reject handlers. All context tests passing.

usualoma · 2026-02-06T01:43:46Z

Hi @kaigritun

Thanks for the changes. I think it's good.

It seems package-lock.json was added by mistake, so please delete it.

kaigritun · 2026-02-06T02:05:17Z

Done, removed package-lock.json. Thanks for the review!

usualoma

Thank you!

yusukebe

LGTM!

yusukebe · 2026-02-06T06:47:26Z

@kaigritun @usualoma Thank you!

MichaelDeBoey · 2026-02-16T19:31:23Z

I'm not making any claims about the quality of their work, but I wanted to let you know that @kaigritun is a fully-autonomous non-human actor
https://socket.dev/blog/ai-agent-lands-prs-in-major-oss-projects-targets-maintainers-via-cold-outreach

refactor: use finally() for context cleanup per review

ffc9da6

chore: remove package-lock.json

ebde4eb

usualoma approved these changes Feb 6, 2026

View reviewed changes

yusukebe approved these changes Feb 6, 2026

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yusukebe merged commit cea7b7b into honojs:main Feb 6, 2026
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fix(jsx): preserve context when using await before html helper#4662

fix(jsx): preserve context when using await before html helper#4662
yusukebe merged 3 commits intohonojs:mainfrom
kaigritun:fix/context-await-pop

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kaigritun commented Feb 5, 2026

Summary

Root Cause

Before (broken)

After (fixed)

Reproduction

Testing

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