fix: correctly exclude net-label-only nets from MSP pair queue (issue #79)

[AXGZ21]

Closes #79

/claim #79

Problem

When pins are connected only via netConnections (net labels), the MspConnectionPairSolver was incorrectly creating MSP pairs and drawing traces between them. Net labels are meant to represent virtual connections — they should not produce routed traces.

Root Cause

The previous fix used directConnMap.getNetConnectedToId(pinId) which performs a net-level lookup and produces false negatives for nets that mix direct connections and net labels. This caused 7 previously-passing tests to regress.

Correct Fix

Build a flat Set of all pinIds that appear in at least one directConnections entry, then exclude any globalNet whose pins are entirely absent from that set:

const directlyConnectedPins = new Set<string>()
for (const dc of inputProblem.directConnections) {
  for (const pid of dc.pinIds) {
    directlyConnectedPins.add(pid)
  }
}
this.queuedDcNetIds = Object.keys(netConnMap.netMap).filter((netId) => {
  const allIds = netConnMap.getIdsConnectedToNet(netId) as string[]
  return allIds.some((id) => directlyConnectedPins.has(id))
})

This precisely identifies "net-label-only" nets without affecting mixed nets.

Results

Metric	Before	After
Tests passing	42/55	50/55
Tests failing	8	0
Format check	✓	✓
Type check	✓	✓

The 5 skipped tests were already skipped on main. Snapshots updated to reflect correct output.

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Project	Deployment	Actions	Updated (UTC)
schematic-trace-solver	Ready	Preview, Comment	Mar 24, 2026 3:21pm

[AXGZ21]

🎬 Demo: Before / After — Issue #79 (PR #140)

Recorded with — runs the solver live on both branches, captures each stage as frames, encodes 648 frames (27s) to WebM + GIF via ffmpeg.

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What this shows

	BEFORE (main)	AFTER (fix/issue-79)
	4 pairs queued — GND (net-label-only) incorrectly included	2 pairs — VCC + EN (direct-wire nets only)
Full pipeline traces	Spurious traces drawn between net-label-only pins	Clean — net labels annotated, no extra traces
bun test v1.3.11 (af24e281)	42 pass / 8 fail	50 pass / 0 fail

▶ Download full WebM (https://github.com/AXGZ21/schematic-trace-solver/blob/fix/issue-79/demo/pr140-demo.webm)

Fix