[DateTimePicker] Publish sistent's own props type instead of the optional peer's

[Valyrian-Code]

Notes for Reviewers

This PR fixes #1749

@mui/x-date-pickers is an optional peer, so a consumer is entitled to skip it, but the published declaration bundle named it and the reference then failed two ways: TS2307 under skipLibCheck: false, and a silent any under skipLibCheck: true.

Removing the re-export alone was not enough

The issue suggests dropping the barrel's export type { DateTimePickerProps }. I tried exactly that first and rebuilt — dist/index.d.ts still had:

import { DateTimePickerProps } from '@mui/x-date-pickers/DateTimePicker';

because the exported component was itself declared with that type:

declare const DateTimePicker: React.ForwardRefExoticComponent<
  DateTimePickerProps & React.RefAttributes<HTMLDivElement>
>;

so the import survived to serve that declaration. Two references, not one — it went 2 → 1, which means the @mui/x-date-pickers entry in OPTIONAL_PEERS_ON_THE_RECORD still could not be deleted (the guard asserts each exemption is still needed and fails on a stale one).

What this does instead

DateTimePicker now publishes sistent's own DateTimePickerProps interface rather than aliasing the peer's. Named props stay checked; a string index signature keeps every other picker prop accepted and forwarded, so this loosens rather than narrows the public surface. MUI's real type stays as a module-local import type used only in positions the declaration bundle erases, so the runtime React.lazy deferral is untouched.

One non-obvious detail, flagged because it is easy to "simplify" away in review: the forwardRef results are annotated explicitly with a DateTimePickerComponent alias. Left to inference, forwardRef<T, P> returns ForwardRefExoticComponent<PropsWithoutRef<P> & ...>, and PropsWithoutRef<P> resolves to Omit<P, 'ref'> when P has an index signature — whose keyof P is string | number, collapsing the interface to { [x: string]: unknown } and silently discarding every named prop's type. <DateTimePicker value="not a date" /> then compiles clean, which would be worse than the bug being fixed. The built output is declare const DateTimePicker: DateTimePickerComponent;, not the collapsed Omit<..., "ref"> form.

I also reworded a comment in DateTimePicker.tsx because my first draft quoted a literal import ... from '@mui/x-date-pickers/...' statement in prose, which optionalPeerDependencies.test.ts correctly flagged — that scanner deliberately does not strip comments. Reworded the prose rather than touching the guard.

Verification

Against a clean consumer built from npm pack, with both optional peers confirmed absent:

• Both dist/index.d.ts and dist/index.d.mts reference @mui/x-date-pickers zero times (specifier positions, comments stripped, same detector the guard uses).
• The probe from the issue no longer compiles, which is the fix — the type is real rather than any:

  probe.ts(4,14): error TS2322: Type 'true' is not assignable to type 'false'.
  

• require('@sistent/sistent') still loads with the peers absent, so the runtime half is unaffected.
• Under skipLibCheck: false the only remaining TS2307s come from @meshery/schemas referencing @reduxjs/toolkit — the pre-existing UNDECLARED_BY_DESIGN exemption, unrelated to this change.
• Consumer compatibility spot-checks: spreading a full MUI DateTimePickerProps value into the component still compiles, as do two-parameter onChange handlers, views / ampm / slotProps / sx / ref / data-testid, while value={'not a date'} and onChange={(n: number) => {}} still error.
• CI=1 jest: 466 passing, 26 suites. eslint . clean. prettier --check clean on the touched files.

Because the count is now zero, the @mui/x-date-pickers entry is deleted from OPTIONAL_PEERS_ON_THE_RECORD and the surrounding comment updated — react is the sole remaining entry and it is permanent rather than a deferred fix, which the old wording ("the fix is to stop naming them in the public type surface") no longer described. AGENTS.md gets the same correction plus a short note that dropping a type re-export does not on its own remove a peer an exported component is still typed with.

One known limitation

Assigning a MUI props value to sistent's DateTimePickerProps in a non-JSX position stops compiling:

const p: DateTimePickerProps = someMuiPropsValue; // index signature missing

An interface source gets no implicit index signature. JSX spread — the common case — works. This cannot be fixed without dropping the index signature, which would break the far more common spread and MUI-only-prop cases, so I took this trade deliberately.

Happy to switch to the smaller variant instead — dropping the public DateTimePickerProps export entirely and keeping the props interface non-exported — which matches the issue's literal wording, also reaches zero, and avoids the index-signature loosening. I raised both options on the issue; this is the one that keeps the existing public type working, but it is your call and the change is small either way.

Signed commits

• Yes, I signed my commits.

Summary by CodeRabbit

• Bug Fixes

  • Improved the published TypeScript declarations for DateTimePicker.
  • DateTimePicker consumers no longer need the optional date-picker package’s types exposed in the component’s public props.
  • Added clearer local prop typing while preserving existing DateTimePicker behavior and configuration options.

• Documentation

  • Clarified guidance for handling optional peer dependencies and public type exports.

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[coderabbitai]

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ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

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Run ID: caef4e51-7756-484a-9f63-0cd05c767b6d

📥 Commits

Reviewing files that changed from the base of the PR and between 846866a and f63d57c.

📒 Files selected for processing (4)

• AGENTS.md
• src/__testing__/publishedTypeSurfaceDependencies.test.ts
• src/base/DateTimePicker/DateTimePicker.tsx
• src/base/DateTimePicker/index.tsx

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📝 Walkthrough

Walkthrough

DateTimePicker now exports local props typings instead of exposing @mui/x-date-pickers types. Its lazy runtime rendering remains intact, while the published declaration dependency test removes the MUI picker exemption and documentation records the type-surface rule.

Changes

Optional peer type-surface cleanup

Layer / File(s)	Summary
Public DateTimePicker contract src/base/DateTimePicker/DateTimePicker.tsx, src/base/DateTimePicker/index.tsx	Exports local DateTimePickerProps, types the lazy and forwarded-ref components with it, and casts props only when rendering the MUI picker.
Dependency surface validation src/__testing__/publishedTypeSurfaceDependencies.test.ts, AGENTS.md	Removes @mui/x-date-pickers from the optional-peer exemption list and documents that peer-only type re-exports do not prevent declaration-level peer references.

Estimated code review effort: 2 (Simple) | ~15 minutes

Possibly related PRs

• layer5io/sistent#1732: Both modify the optional MUI picker handling in DateTimePicker.tsx.
• layer5io/sistent#1737: Both update the lazy-loaded optional MUI DateTimePicker wrapper.
• layer5io/sistent#1750: Both modify optional-peer handling in the published type-surface dependency test.

Suggested labels: area/ci

Suggested reviewers: copilot, codeahmedjamil

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title matches the main change: publishing Sistent’s own DateTimePicker props instead of the optional peer’s type.
Linked Issues check	✅ Passed	The PR removes the optional @mui/x-date-pickers type dependency from the public surface and updates the exemption guard as #1749 requested.
Out of Scope Changes check	✅ Passed	The added doc and test updates directly support the type-surface fix and do not introduce unrelated scope.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

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