fix: carry inductor maxCurrentRating into source_component (#2837)

[DPS0340]

Closes #2837.

maxCurrentRating is declared on InductorProps and max_current_rating exists on the simple_inductor schema, but doInitialSourceRender() never wrote it — the value was dropped with no warning.

                                  before      after
L1  (no rating)                   undefined   undefined
L2  maxCurrentRating="2A"         undefined   2
L3  maxCurrentRating={0.5}        undefined   0.5
L4  maxCurrentRating="500mA"      undefined   0.5

The part that isn't obvious

My first attempt used parseFloat, copying Fuse's approach, and the checker caught it: parseFloat("500mA") returns 500 — a 1000× error that would have written a plainly wrong value into circuit JSON rather than leaving it absent.

The reason Fuse gets away with parseFloat is that its ratings are conventionally written without SI prefixes. maxCurrentRating has no zod transform either, unlike capacitor's maxVoltageRating:

capacitor: maxVoltageRating: z.ZodOptional<z.ZodEffects<..., number, string | number>>  ← converted for you
inductor:  maxCurrentRating: z.ZodOptional<z.ZodUnion<[z.ZodString, z.ZodNumber]>>       ← raw string arrives

I then tried parseSiUnit, which returns NaN for "2A" — it doesn't expect a unit suffix. parseAndConvertSiUnit(...).value is the one that handles both, which I verified directly before using it:

"2A" → 2    "500mA" → 0.5    "1.5A" → 1.5    "2" → 2    "abc" → NaN

NaN/null/undefined all resolve to undefined so a malformed rating leaves the field absent rather than poisoning it.

Verification

The test bites. Reverting only Inductor.ts:

expect(ratingByName.L2).toBe(2)
Received: undefined
(fail) <inductor /> carries maxCurrentRating into source_component

It covers all four cases in one board — omitted, string with unit, plain number, and prefixed unit — so the 1000× bug specifically is pinned by expect(ratingByName.L4).toBe(0.5).

Suite: 1260 pass / 0 fail, no snapshots changed (this only adds a source field). biome format and tsc --noEmit clean.

Other props from the same sweep

I cross-referenced every *Props interface against the props each component reads. Several others appear unread — Capacitor.bypassFor/bypassTo/schSize, Resistor.schSize/tolerance, Board.topSolderMaskColor/bottomSolderMaskColor, Chip.internalCircuit/pinCompatibleVariants. I deliberately didn't touch those: unlike this one they have no obvious destination field, so "fixing" them would mean inventing schema semantics. Listed in #2837 in case they're worth triaging.

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Project	Deployment	Actions	Updated (UTC)
tscircuit-core-benchmarks	Ready	Preview, Comment	Jul 25, 2026 5:11pm

[DPS0340]

Housekeeping — rebased onto current main (d99c99f), still 1260 pass / 0 fail. No behaviour change.

Since I have several PRs open here now, a note on how they interact so none of this lands on you:

Five of the seven are fully independent — they touch different files and merge in any order:

PR	file
#2838	Inductor.ts
#2844	Hole.ts, PlatedHole.ts
#2846	Group/Group.ts (group insert sites)
#2840	Group/Group.ts (pcb_trace segment insert)
#2842	NormalComponent.ts, Group/Group.ts, Group_doInitialPcbComponentAnchorAlignment.ts

Two pairs conflict, and both are trivial:

1. fix: omit the voltage half of the fuse label when voltageRating is absent (#2833) #2834 ↔ fix: honour schShowRatings={false} on fuse (#2835) #2836 — both edit Fuse._getSchematicSymbolDisplayValue(). Whichever merges first, the other needs the two guards stacked:

   if (this._parsedProps.schShowRatings === false) return undefined   // #2836
   if (voltage === undefined || Number.isNaN(voltage)) return currentDisplay  // #2834
   return `${currentDisplay} / ${formatSiUnit(voltage)}V`

   They're orthogonal (one suppresses the whole label, the other drops just the voltage half), so the combined behaviour is well-defined. Both test files also touch fuse.test.tsx, appending separate tests.

2. fix: carry net highlightColor into pcb_trace.highlight_color (#2839) #2840 ↔ fix: write display_offset_x/y as display strings (#2841) #2842 — both add a field to nearby inserts in Group.ts; the resolution is to keep both lines.

Happy to do the merge myself: say the word and I'll combine any subset into a single PR, or rebase the losers as soon as the first one lands. I'd rather you not spend time on conflict resolution for my changes.

I verified the above rather than assuming it — checked all 21 branch pairs for conflicts and confirmed each rebases cleanly onto d99c99f.