fix(form-core): prevent double re-render when no async validators

[tt-a1i]

Summary

• Fix fields re-rendering twice on each keystroke when there are no async validators
• Add test case to verify isValidating doesn't toggle unnecessarily

Problem

As reported in #1130, fields were re-rendering twice on each keystroke because isValidating was being set to true then immediately false in validateAsync, even when there were no async validators to run.

Root Cause

In FieldApi.validateAsync:

// Before: Always toggled isValidating regardless of validators
if (!this.state.meta.isValidating) {
  this.setMeta((prev) => ({ ...prev, isValidating: true }))  // Render 1
}
// ... later ...
this.setMeta((prev) => ({ ...prev, isValidating: false }))   // Render 2

Solution

Check if there are actual async validators before toggling isValidating:

const hasAsyncValidators =
  validates.some((v) => v.validate) ||
  linkedFieldValidates.some((v) => v.validate)

if (hasAsyncValidators) {
  // Only toggle isValidating if we have validators to run
}

Test Plan

• Added test case: should not toggle isValidating when there are no async validators
• All existing tests pass (404 tests in form-core, 78 tests in react-form)

Fixes #1130

[changeset-bot]

🦋 Changeset detected

Latest commit: e77c124

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 13 packages

Name	Type
@tanstack/form-core	Patch
@tanstack/angular-form	Patch
@tanstack/form-devtools	Patch
@tanstack/lit-form	Patch
@tanstack/react-form	Patch
@tanstack/solid-form	Patch
@tanstack/svelte-form	Patch
@tanstack/vue-form	Patch
@tanstack/react-form-devtools	Patch
@tanstack/solid-form-devtools	Patch
@tanstack/react-form-nextjs	Patch
@tanstack/react-form-remix	Patch
@tanstack/react-form-start	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[crutchcorn]

LGTM. Thanks for this!

[nx-cloud]

View your CI Pipeline Execution ↗ for commit e77c124

Command	Status	Duration	Result
nx affected --targets=test:sherif,test:knip,tes...	✅ Succeeded	1m 36s	View ↗
nx run-many --target=build --exclude=examples/**	✅ Succeeded	32s	View ↗

---

☁️ Nx Cloud last updated this comment at 2025-12-15 11:39:00 UTC

[pkg-pr-new]

More templates

• @tanstack/form-example-angular-array
• @tanstack/form-example-angular-large-form
• @tanstack/form-example-angular-simple
• @tanstack/form-example-angular-standard-schema
• @tanstack/form-example-lit-array
• @tanstack/form-example-lit-simple
• @tanstack/form-example-lit-standard-schema
• @tanstack/form-example-lit-ui-libraries
• @tanstack/form-example-react-array
• @tanstack/form-example-react-compiler
• @tanstack/form-example-react-devtools
• @tanstack/form-example-react-dynamic
• @tanstack/field-errors-from-form-validators
• @tanstack/form-example-react-large-form
• @tanstack/form-example-react-next-server-actions
• @tanstack/form-example-react-query-integration
• @tanstack/form-example-remix
• @tanstack/form-example-react-simple
• @tanstack/form-example-react-standard-schema
• @tanstack/form-example-react-tanstack-start
• @tanstack/form-example-react-ui-libraries
• @tanstack/form-example-solid-array
• @tanstack/form-example-solid-devtools
• @tanstack/form-example-solid-large-form
• @tanstack/form-example-solid-simple
• @tanstack/form-example-solid-standard-schema
• @tanstack/form-example-vue-array
• @tanstack/form-example-vue-simple
• @tanstack/form-example-vue-standard-schema
• @tanstack/form-example-svelte-array
• @tanstack/form-example-svelte-large-form
• @tanstack/form-example-svelte-simple
• @tanstack/form-example-svelte-standard-schema

@tanstack/angular-form

npm i https://pkg.pr.new/@tanstack/angular-form@1929

@tanstack/form-core

npm i https://pkg.pr.new/@tanstack/form-core@1929

@tanstack/form-devtools

npm i https://pkg.pr.new/@tanstack/form-devtools@1929

@tanstack/lit-form

npm i https://pkg.pr.new/@tanstack/lit-form@1929

@tanstack/react-form

npm i https://pkg.pr.new/@tanstack/react-form@1929

@tanstack/react-form-devtools

npm i https://pkg.pr.new/@tanstack/react-form-devtools@1929

@tanstack/react-form-nextjs

npm i https://pkg.pr.new/@tanstack/react-form-nextjs@1929

@tanstack/react-form-remix

npm i https://pkg.pr.new/@tanstack/react-form-remix@1929

@tanstack/react-form-start

npm i https://pkg.pr.new/@tanstack/react-form-start@1929

@tanstack/solid-form

npm i https://pkg.pr.new/@tanstack/solid-form@1929

@tanstack/solid-form-devtools

npm i https://pkg.pr.new/@tanstack/solid-form-devtools@1929

@tanstack/svelte-form

npm i https://pkg.pr.new/@tanstack/svelte-form@1929

@tanstack/vue-form

npm i https://pkg.pr.new/@tanstack/vue-form@1929

commit: e77c124

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.74%. Comparing base (6892ed0) to head (e77c124).
⚠️ Report is 96 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1929      +/-   ##
==========================================
- Coverage   90.35%   89.74%   -0.61%     
==========================================
  Files          38       48      +10     
  Lines        1752     1931     +179     
  Branches      444      483      +39     
==========================================
+ Hits         1583     1733     +150     
- Misses        149      177      +28     
- Partials       20       21       +1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.