fix: type serverValidate decoded values by kkkhs · Pull Request #2332 · TanStack/form

kkkhs · 2026-08-13T12:32:16Z

🎯 Changes

Fixes #1438. createServerValidate exposed form-value types instead of decoded form data.

Fix: Return decoded decode-formdata value types from the public adapter API, and keep form-shaped casts only for validator and ServerFormState internals.

Test: Added Next.js and Remix adapter type regression coverage.

✅ Checklist

I have followed the steps in the Contributing guide.
I have tested this code locally with pnpm test:pr.

🚀 Release Impact

This change affects published code, and I have generated a changeset.
This change is docs/CI/dev-only (no release).

coderabbitai · 2026-08-13T12:32:26Z

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

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Run ID: e639946a-e6ab-4ff0-af79-709c1d737243

📥 Commits

Reviewing files that changed from the base of the PR and between 7b8fc1d and 7e8652e.

📒 Files selected for processing (5)

.changeset/quiet-lamps-warn.md
packages/react-form-nextjs/src/createServerValidate.ts
packages/react-form-nextjs/tests/createServerValidate.test-d.ts
packages/react-form-remix/src/createServerValidate.ts
packages/react-form-remix/tests/createServerValidate.test-d.ts

📝 Walkthrough

Walkthrough

createServerValidate now separates decoded form data from cast validation values in the Next.js and Remix adapters. Type tests verify that returned fields are typed as unknown, and a patch Changeset documents the correction.

Changes

Server validation type correction

Layer / File(s)	Summary
Separate decoded and validation values `packages/react-form-nextjs/src/createServerValidate.ts`, `packages/react-form-remix/src/createServerValidate.ts`, `.changeset/quiet-lamps-warn.md`	Both adapters pass cast values to server validation while preserving decoded values for successful returns. Server error state stores the cast validation values. The Changeset marks patch releases.
Verify decoded return types `packages/react-form-nextjs/tests/createServerValidate.test-d.ts`, `packages/react-form-remix/tests/createServerValidate.test-d.ts`	Type tests assert that awaited results use `Record<string, unknown>` and that fields such as `age` are typed as `unknown`.

Estimated code review effort: 2 (Simple) | ~10 minutes

Mergeability Score: ⚪ Minimal · up to 7e865

This localized change corrects the public types returned by the Next.js and Remix server-validation adapters while preserving existing runtime behavior; no actionable merge-blocking risk remains after normal checks and review.

Possibly related PRs

TanStack/form#2308: Both PRs update createServerValidate documentation or behavior for the Next.js and Remix adapters.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	The changes address issue `#1438` by preserving decoded types in public returns and adding regression tests for both adapters.
Out of Scope Changes check	✅ Passed	All changes are directly related to correcting createServerValidate type inference and documenting the published fix.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Title check	✅ Passed	The title clearly identifies the fix to decoded value types returned by server validation.
Description check	✅ Passed	The description explains the change, motivation, tests, checklist completion, and changeset release impact.

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Copilot

Pull request overview

Fixes inaccurate type inference for createServerValidate in the Next.js and Remix adapters so the successful return value is typed as the decoded FormData output (instead of the inferred form/defaultValues type), matching runtime behavior described in #1438.

Changes:

Stop casting decoded values to TFormData at the point of decoding; only cast where required for validation and ServerFormState.
Add type regression tests in both adapters asserting serverValidate returns decoded-formdata-shaped values (Record<string, unknown>).
Add a changeset bumping both adapter packages with a patch release.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
packages/react-form-nextjs/src/createServerValidate.ts	Returns decoded `FormData` values without forcing `TFormData` typing; keeps cast only for validator + `ServerFormState` error payload.
packages/react-form-remix/src/createServerValidate.ts	Same typing adjustment as Next.js adapter for decoded values vs validation-cast values.
packages/react-form-nextjs/tests/createServerValidate.test-d.ts	Adds type regression test asserting decoded-values return type for `serverValidate`.
packages/react-form-remix/tests/createServerValidate.test-d.ts	Adds equivalent type regression test for Remix adapter.
.changeset/quiet-lamps-warn.md	Declares patch releases for both adapters describing the return-type fix.

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nx-cloud · 2026-08-13T12:56:53Z

View your CI Pipeline Execution ↗ for commit 7e8652e

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☁️ Nx Cloud last updated this comment at 2026-08-13 13:05:10 UTC

pkg-pr-new · 2026-08-13T12:58:12Z

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commit: 7e8652e

codecov-commenter · 2026-08-13T13:05:27Z

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Codecov Report

❌ Patch coverage is 0% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 0.00%. Comparing base (6892ed0) to head (7e8652e).
⚠️ Report is 273 commits behind head on main.

Files with missing lines	Patch %	Lines
...ages/react-form-nextjs/src/createServerValidate.ts	0.00%	1 Missing and 1 partial ⚠️
...kages/react-form-remix/src/createServerValidate.ts	0.00%	1 Missing and 1 partial ⚠️
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Additional details and impacted files

@@            Coverage Diff             @@
##             main   #2332       +/-   ##
==========================================
- Coverage   90.35%   0.00%   -90.36%     
==========================================
  Files          38       6       -32     
  Lines        1752      48     -1704     
  Branches      444      14      -430     
==========================================
- Hits         1583       0     -1583     
+ Misses        149      40      -109     
+ Partials       20       8       -12

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MILLERMARRU

I read through createServerValidate.ts in both react-form-nextjs and react-form-remix and the change is identical in each, which is good since they're meant to stay in sync. The split between values (untyped decoded data) and validationValues (cast for the validator call) is the right fix, the validator legitimately needs TFormData shape to type-check against the user's validation function, but claiming the same type for what callers get back from serverValidate() or catch in ServerValidateError.formState.values was misleading since decode() doesn't actually enforce that shape at runtime. The new .test-d.ts files cover exactly this distinction with expectTypeOf.

fix(*): type serverValidate decoded values

7e8652e

kkkhs marked this pull request as ready for review August 13, 2026 12:39

Copilot AI lite review requested due to automatic review settings August 13, 2026 12:39

Copilot started reviewing on behalf of kkkhs August 13, 2026 12:40 View session

Copilot AI reviewed Aug 13, 2026

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MILLERMARRU reviewed Aug 16, 2026

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fix: type serverValidate decoded values - #2332

fix: type serverValidate decoded values#2332
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kkkhs:agent/fix-servervalidate-type-inference

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