Scope trace length checks to exact routed endpoints

[seveibar]

Summary

• when a two-port source trace has a PCB trace that explicitly references both mapped PCB endpoints, measure only that exact-endpoint trace
• ignore unrelated MST branches that merely inherit the same source trace ID
• preserve current behavior for one-port-to-net traces, authoritative trace_length values, through-pad or metadata-poor routes, and other cases without an exact endpoint match

Regression coverage

• suppresses the three smart-watch-style explicit two-port MST false positives
• retains a real violation on the direct endpoint trace
• retains the C9-style one-port-to-net warning
• falls back to current attribution when exact endpoint metadata is unavailable

Validation

• bun test tests/lib/check-pcb-trace-lengths.test.ts (6 passed)
• bun test (212 passed)
• bunx tsc --noEmit
• bun run build
• bunx biome format lib/check-pcb-trace-lengths.ts tests/lib/check-pcb-trace-lengths.test.ts
• winning smart-watch circuit JSON: warnings reduced from 4 to the one genuine C9 GND drop (5.062790 mm > 5 mm)

The repository-wide format command still reports the existing Biome 1 MiB limit on three unchanged JSON fixtures; both changed files pass the formatter directly.

[graphite-app]

A *.test.ts file may have AT MOST one test(...) call, but this file now contains at least 4 test(...) calls (at lines 129, 177, 215, and 245). The new tests added in this diff should be split into separate, numbered test files. For example: check-pcb-trace-lengths1.test.ts, check-pcb-trace-lengths2.test.ts, check-pcb-trace-lengths3.test.ts, check-pcb-trace-lengths4.test.ts, etc. Each file should contain exactly one test(...) call.

Suggested change

	test("ignores unrelated long MST branches when exact two-port traces are short", () => {
	const cases = [
	{ id: "charger_ground", maximum: 5, exact: 3.94, branch: 10.71 },
	{ id: "vdd1_decoupling", maximum: 3, exact: 1.16, branch: 6.47 },
	{ id: "regulator_output", maximum: 6, exact: 1.57, branch: 17.37 },
	]
	const multidropCircuitJson = cases.flatMap(
	({ id, maximum, exact, branch }): AnyCircuitElement[] => {
	const sourceTraceId = `source_trace_${id}`
	const startSourcePortId = `source_port_${id}_start`
	const endSourcePortId = `source_port_${id}_end`
	const branchSourcePortId = `source_port_${id}_branch`
	const startPcbPortId = `pcb_port_${id}_start`
	const endPcbPortId = `pcb_port_${id}_end`
	const branchPcbPortId = `pcb_port_${id}_branch`
	return [
	{
	type: "source_trace",
	source_trace_id: sourceTraceId,
	connected_source_port_ids: [startSourcePortId, endSourcePortId],
	connected_source_net_ids: [],
	max_length: maximum,
	},
	makePcbPort(startPcbPortId, startSourcePortId),
	makePcbPort(endPcbPortId, endSourcePortId),
	makePcbPort(branchPcbPortId, branchSourcePortId),
	makeStraightPcbTrace({
	pcbTraceId: `pcb_trace_${id}_exact`,
	sourceTraceId,
	startPcbPortId,
	endPcbPortId,
	length: exact,
	}),
	makeStraightPcbTrace({
	pcbTraceId: `pcb_trace_${id}_unrelated_branch`,
	sourceTraceId,
	startPcbPortId,
	endPcbPortId: branchPcbPortId,
	length: branch,
	}),
	]
	},
	)
	expect(checkPcbTraceLengths(multidropCircuitJson)).toEqual([])
	})
	test("retains a violation on the exact two-port PCB trace", () => {
	const exactViolationCircuitJson = [
	{
	type: "source_trace",
	source_trace_id: "source_trace_exact_violation",
	connected_source_port_ids: ["source_port_a", "source_port_b"],
	connected_source_net_ids: [],
	max_length: 5,
	},
	makePcbPort("pcb_port_a", "source_port_a"),
	makePcbPort("pcb_port_b", "source_port_b"),
	makePcbPort("pcb_port_branch", "source_port_branch"),
	makeStraightPcbTrace({
	pcbTraceId: "pcb_trace_exact_violation",
	sourceTraceId: "source_trace_exact_violation",
	startPcbPortId: "pcb_port_a",
	endPcbPortId: "pcb_port_b",
	length: 7,
	}),
	makeStraightPcbTrace({
	pcbTraceId: "pcb_trace_unrelated_long_branch",
	sourceTraceId: "source_trace_exact_violation",
	startPcbPortId: "pcb_port_a",
	endPcbPortId: "pcb_port_branch",
	length: 12,
	}),
	] as AnyCircuitElement[]
	expect(checkPcbTraceLengths(exactViolationCircuitJson)).toEqual([
	expect.objectContaining({
	pcb_trace_id: "pcb_trace_exact_violation",
	source_trace_id: "source_trace_exact_violation",
	actual_trace_length: 7,
	maximum_trace_length: 5,
	}),
	])
	})
	test("retains one-port-to-net trace length warnings", () => {
	const portToNetCircuitJson = [
	{
	type: "source_trace",
	source_trace_id: "source_trace_ground_drop",
	connected_source_port_ids: ["source_port_c9_ground"],
	connected_source_net_ids: ["source_net_ground"],
	max_length: 5,
	},
	makePcbPort("pcb_port_c9_ground", "source_port_c9_ground"),
	makePcbPort("pcb_port_c3_ground", "source_port_c3_ground"),
	makeStraightPcbTrace({
	pcbTraceId: "pcb_trace_c9_to_ground",
	sourceTraceId: "source_trace_ground_drop",
	startPcbPortId: "pcb_port_c9_ground",
	endPcbPortId: "pcb_port_c3_ground",
	length: 5.062790456754819,
	}),
	] as AnyCircuitElement[]
	expect(checkPcbTraceLengths(portToNetCircuitJson)).toEqual([
	expect.objectContaining({
	pcb_trace_id: "pcb_trace_c9_to_ground",
	source_trace_id: "source_trace_ground_drop",
	actual_trace_length: 5.062790456754819,
	maximum_trace_length: 5,
	}),
	])
	})
	test("keeps existing attribution when no exact endpoint route is exposed", () => {
	const routeWithoutEndpointMetadata = [
	{
	type: "source_trace",
	source_trace_id: "source_trace_without_endpoint_metadata",
	connected_source_port_ids: ["source_port_a", "source_port_b"],
	connected_source_net_ids: [],
	max_length: 5,
	},
	makePcbPort("pcb_port_a", "source_port_a"),
	makePcbPort("pcb_port_b", "source_port_b"),
	{
	type: "pcb_trace",
	pcb_trace_id: "pcb_trace_without_endpoint_metadata",
	source_trace_id: "source_trace_without_endpoint_metadata",
	trace_length: 7,
	route: [],
	},
	] as AnyCircuitElement[]
	expect(checkPcbTraceLengths(routeWithoutEndpointMetadata)).toEqual([
	expect.objectContaining({
	pcb_trace_id: "pcb_trace_without_endpoint_metadata",
	source_trace_id: "source_trace_without_endpoint_metadata",
	actual_trace_length: 7,
	maximum_trace_length: 5,
	}),
	])
	})

Spotted by Graphite (based on custom rule: Custom rule)



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[tscircuitbot]

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