Update Zod from v3 to v4 and refactor validation schemas

[SvenVw]

Summary by CodeRabbit

• Chores

  • Updated Zod validation library from v3 to v4.

• Refactor

  • Unified validation error handling across forms to the new Zod v4 style (dynamic error callbacks / "error" payloads).
  • Improved date/number preprocessing and default initialization to reduce spurious errors and better handle string input.
  • Preserved existing validation rules and user-facing message texts while changing how validation errors are reported.

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Closes #432

[changeset-bot]

🦋 Changeset detected

Latest commit: 7161c86

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

This PR includes changesets to release 1 package

Name	Type
@svenvw/fdm-app	Patch

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[coderabbitai]

Walkthrough

Migrates fdm-app to Zod v4 and updates many Zod schemas to use the v4 error API (replacing required_error/invalid_type_error/message with error callbacks), converts some z.coerce usages to z.preprocess, and changes some .default() to .prefault(); package.json zod dependency bumped.

Changes

Cohort / File(s)	Summary
Release Management ​.changeset/many-sails-hang.md	Added changeset documenting a patch bump for the migration.
Dependency Update fdm-app/package.json	Bumped zod from ^3.25.76 to ^4.3.6.
Fertilizer Schemas fdm-app/app/components/blocks/fertilizer/formschema.tsx, fdm-app/app/components/blocks/fertilizer-applications/formschema.tsx	Replaced per-constraint required_error/invalid_type_error/message with error callbacks; switched some coercions to preprocess + z.number()/z.date(); moved some default → prefault; refinement error payloads now use error with paths.
Cultivation / Rotation / Harvest fdm-app/app/components/blocks/cultivation/schema.ts, fdm-app/app/components/blocks/rotation/schema.ts, fdm-app/app/components/blocks/harvest/schema.tsx	Date fields now use z.preprocess for string→Date and conditional error callbacks; .default(null) → .prefault(null) for end-date(s); refinements return error entries with paths.
Field & Organic Certification fdm-app/app/components/blocks/field/schema.tsx, fdm-app/app/components/blocks/organic-certification/schema.ts	Replaced required_error/message with conditional error handlers; date fields use preprocess and error callbacks.
Soil Schemas & Uploads fdm-app/app/components/blocks/soil/formschema.tsx, fdm-app/app/components/blocks/soil/form-upload.tsx, fdm-app/app/components/blocks/mijnpercelen/form-upload.tsx	Switched numeric/date validators to error callback pattern and preprocess; file refine validators now return error instead of message.
Route / Page Schemas fdm-app/app/routes/... (farm.*, organization.*, farm.create._index.tsx, signin._index.tsx, welcome.tsx)	Systematically migrated validators to error callbacks, converted some z.coerce usages to preprocess + z.number()/z.date(), and changed some .default() → .prefault().
Integration Logging fdm-app/app/integrations/nmi.ts	Zod error logging changed from .format() to z.treeifyError() for validation failures.

Sequence Diagram(s)

(omitted)

Estimated code review effort

🎯 4 (Complex) | ⏱️ ~45 minutes

Possibly related PRs

• Release/2025-10 #320 — Large Zod v4 migration and schema/error-key changes in fdm-app (strong overlap with these validation edits).
• Add start and end date validation for the cultivation harvest bulk action #414 — Modifies cultivation/harvest date validation logic (touches same files and refinements altered here).
• Hotfix/20250612 custom fertilizer #165 — Changes fertilizer form validation (overlaps with numeric/coercion and error handling updates).

Suggested reviewers

• gerardhros

Poem

🐰 I hopped from v3 into v4 tonight,
Errors now whisper only when input's light,
Prefault seeds and preprocess leaves,
Schemas trimmed like winter eaves,
A rabbit cheers the migration — soft and bright.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 50.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main change: updating Zod from v3 to v4 and refactoring validation schemas to align with v4 requirements.
Linked Issues check	✅ Passed	The PR successfully addresses issue #432 by updating zod from ^3.25.76 to ^4.3.6 and systematically refactoring validation schemas across all affected files to use v4 patterns (error callbacks, preprocess, prefault).
Out of Scope Changes check	✅ Passed	All changes are directly related to the Zod v3 to v4 migration. Minor formatting adjustments in some files and import cleanup are incidental to the migration effort.

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✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch FDM432

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[coderabbitai]

Actionable comments posted: 3

🤖 Fix all issues with AI agents

In `@fdm-app/app/components/blocks/harvest/schema.tsx`:
- Around line 25-163: The numeric harvest/yield fields (b_lu_yield,
b_lu_yield_fresh, b_lu_yield_bruto, b_lu_dm, b_lu_tarra, b_lu_uww, b_lu_moist
and b_lu_cp) currently use z.int() which fails on string inputs from FormData;
update each schema block to use z.coerce.number().int() (keeping the existing
z.preprocess((val)=> val===""? undefined: val) and the same chained validators
like .positive(), .max(), .min(), .finite(), .optional()) so strings are coerced
to numbers before integer validation—follow the pattern used by
b_lu_n_harvestable for guidance.

In `@fdm-app/app/routes/welcome.tsx`:
- Around line 49-65: The firstname and surname schema entries in FormSchema use
z.coerce.string(), which coerces undefined to "undefined" and bypasses your
undefined checks; change both to use z.string() instead (preserve the existing
custom error callbacks and .min(1) validators) so the undefined-checking error
functions for firstname and surname run correctly and values like "undefined"
are not accepted.

In `@fdm-app/package.json`:
- Line 90: You added "zod": "^4.3.6" in package.json; validate and adapt code
for Zod v4 compatibility: run the zod-v3-to-v4 codemod across the repo, update
any schema usages that rely on deprecated options (e.g.,
message/required_error), adjust places handling ZodError formatted output,
verify .default() semantics and string validators (e.g., z.ip() → z.ipv4()), and
confirm TypeScript types with `@hookform/resolvers` (ensure you’re on v5.2.2 and
fix any type mismatches in form schemas and error handling like useForm resolver
integrations). After changes, run full typecheck and form-related tests/manual
flows to confirm validation and inference remain correct.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 88.07%. Comparing base (f154ed0) to head (7161c86).
⚠️ Report is 6 commits behind head on development.

Additional details and impacted files

@@             Coverage Diff              @@
##           development     #433   +/-   ##
============================================
  Coverage        88.07%   88.07%           
============================================
  Files               91       91           
  Lines             4621     4621           
  Branches          1492     1492           
============================================
  Hits              4070     4070           
  Misses             551      551           

Flag	Coverage Δ
fdm-calculator	88.76% <ø> (ø)
fdm-core	86.77% <ø> (ø)
fdm-data	92.12% <ø> (ø)

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[BoraIneviNMI]

It looks good. I see all the necessary required_error and invalid_type_error keys in the Zod 3 code are taken care of. I have one small suggestion.