[upstream #4916] feat(dashboard): Send only changed fields on detail page updates

[ayim]

Mirrored from vendurehq#4916 for the Overwatch review demo.

Original author: @grolmus

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Summary

The dashboard detail-page form engine now submits only the fields the user actually changed on update, instead of resending the entire form payload. This closes a silent data-loss vector: previously, a field left untouched by admin A would be resubmitted at its stale page-load value and could overwrite a concurrent change made by admin B (or an API integration) — no error, success toast.

Design was signed off by @michaelbromley on OSS-567 (targeting minor). This is Tier 1 of his framing (don't send untouched fields); Tier 2 (touched replace-set element conflicts, beyond the merged stock fix) and Tier 3 (optimistic concurrency) remain separate.

Root cause

useGeneratedForm mapped the whole entity into the form and called onSubmit with the entire payload on every save; useDetailPage forwarded it to the update mutation. For replace-semantics fields (facetValueIds, assetIds, scalar stock config, channelIds, prices, promotion conditions/actions, …) the stale value replaced whatever was there.

Change

• form-engine/utils.ts — deepEqual (primitives incl. NaN, Date, arrays, plain objects) and getChangedTopLevelFields(submitted, baseline, fields): the top-level keys that differ from the baseline, plus any input field that is non-nullable (FieldInfo.nullable === false, e.g. id, UpdateShippingMethodInput.translations) which is always sent.
• useGeneratedForm — computes changedFields by deep-comparing the raw submitted values against the form baseline (the values memo) and passes it via a new, backward-compatible 2nd meta arg to onSubmit. RHF dirtyFields is deliberately not used (array-item removal reads as clean → would drop the user's own deletion; assetIds/featuredAssetId are written via setValue with no Controller).
• useDetailPage — on the update path only, prunes the payload to changedFields before transformUpdateInput. Create path is unchanged. Adds a sendAllFieldsOnUpdate?: boolean opt-out. Composes with the existing getChangedStockLevels transform (fix(dashboard): only send edited stock levels on variant update vendurehq/vendure#4834).
• No change to transformUpdateInput's signature (avoids the generic-inference hazard from the OSS-554 fix).

Whole-key granularity: a changed top-level key is sent in full (the entire translations array, facetValueIds, customFields object), preserving the "full translation objects per language" invariant.

Behaviour change / extensions

Update mutations move from full-snapshot to patch-of-changed-fields for all detail pages, including third-party dashboard extensions built on useDetailPage. Core update inputs are patch-style by design, so this is safe for core. Extensions whose custom update mutation relies on receiving unchanged fields can set sendAllFieldsOnUpdate: true.

Test plan

Unit (form-engine/utils.spec.ts, 48 pass): deepEqual (NaN, Date, nested arrays/objects); getChangedTopLevelFields — changed scalar kept, untouched pruned, array add/remove, key deletion, nested translation/customFields, non-nullable always kept, undefined-baseline↔value transitions, missing non-nullable field doesn't throw.

E2E (payload assertions, the strongest proof):

• catalog/product-variants.spec.ts — edit only the SKU → update input is exactly { id, sku } (facetValueIds/assetIds/trackInventory/translations/price omitted). 11/11.
• catalog/products.spec.ts — edit only the name → update input is exactly { id, translations }. 16/16.

Typecheck clean; existing catalog suites green (no regression).

Relates to OSS-567.

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Summary by CodeRabbit

• Tests

  • Added comprehensive end-to-end tests for collections, products, and product variants to verify that update requests include only the fields modified by the user.

• Chores

  • Enhanced the form engine to optimize update payloads by sending only changed fields (with an option to revert to sending all fields if needed).