finding(fields): clearing a `GeolocationField` coordinate emits `undefined`, where the other three `type="number"` widgets emit `null`

[os-sales]

Found while re-deriving the divergence table for #6793. Not fixed there — that card is test-only and touches no widget source.

What was measured

Chromium 141.0.7390.37 (Playwright 1.62.1) was driven key by key on a real input type="number", and the resulting .value sequence was then driven through each widget in happy-dom. Typing 1e into an empty box is the reachable "clear" route: the browser moves .value from '' to '1' to '', and the widget is told the box is now empty.

widget	emission when the box goes empty
CurrencyField	null
PercentField	null
NumberField	null
GeolocationField	{ latitude: undefined }

Same for plain deletion — any route that leaves the box empty. Pinned as current product behaviour in packages/fields/src/__tests__/NumberInputWidgets.browserDeliverable.test.tsx (PR for #6793).

Why it is not cosmetic

GeolocationField builds an object instead of emitting a scalar:

onChange({ ...location, [fieldName]: fieldValue ? Number(fieldValue) : undefined });

undefined and null part company at the persistence boundary. JSON.stringify drops an undefined key entirely, so a cleared latitude can reach the server as an ABSENT key rather than an explicit null. On a PATCH-shaped update an absent key conventionally means "leave it alone" — so the user clears a coordinate, sees an empty box, and the old coordinate survives the save. The other three widgets of this class send an explicit null and do not have that ambiguity.

Not measured here: whether any data adapter in this repo actually round-trips a geolocation clear that way. That is the first thing to check before choosing a fix — the emission asymmetry is measured, the downstream consequence is reasoned.

Context, not a second finding

The class also carries two different parsers — parseFloat in CurrencyField / PercentField, Number in NumberField / GeolocationField. On every string a real browser can deliver they were measured to agree on all rows, so this is latent rather than live; it is worth knowing only because it is the same "one class, two spellings" shape.

Related

#6793 (the test-oracle card this came out of) · #6780 / PR #6801 (the badInput announcement across the same four widgets) · #6765

[claude]

Context from the domain:ui execution seat (PM session session_01CRJge11jso9TpXRWFt1Z49), filed by the implementer of #6793 / PR #6850. ⛔ Grading and domain:* are the triage seat's.

What was measured, and what was not — the card draws the line itself

Measured: clearing a GeolocationField coordinate emits undefined, where CurrencyField, PercentField and NumberField all emit null on the same action. Reachable by any user emptying the box.

Reasoned, ⛔ not measured (and the card says so, which is why it is safe to act on): undefined keys vanish from JSON.stringify, so a cleared coordinate can reach the server as an absent key — conventionally "leave this field alone" — rather than as an explicit null meaning "clear it". ⇒ the user's clear may not persist.

⚠️ Whoever grades this should treat the persistence half as the open question, not as an established consequence. The right first step is to measure what the write path actually does with an absent key versus a null one, before choosing a fix. If absent and null are treated identically downstream, this is a consistency nit; if they are not, it is a data-loss defect on a published widget. The two gradings are far apart and the measurement is cheap.

Related, recorded rather than filed

The four widgets carry two parsers — parseFloat in Currency/Percent, Number in Number/Geolocation. On every string a real browser can deliver they were measured to agree on all rows, so it is latent rather than live. Worth knowing only as the same "one class, two spellings" shape the lane has been tracking; ⛔ not a defect today and ⛔ not a reason to widen this card.

Provenance

Surfaced by #6793's browser-deliverable measurement (Chromium 141 via Playwright, real type="number" input driven key by key with .value and validity.badInput read after each keystroke). PR #6850 carries that table with its provenance — ⛔ do not re-measure it for this card.

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