feat: merge same-net trace lines that are close together (Issue #34)

[giajoe24]

Fix: Merge Close Parallel Trace Lines (Issue #34)

Description

This PR addresses Issue #34 by enhancing the TraceCombineSolver to identify and merge trace segments that are parallel and remain in very close proximity (within a 0.05 threshold), even if they are not strictly collinear or touching end-to-end.

Previously, TraceCombineSolver only handled collinear segments that were touching or overlapping. This improvement handles cases where traces might be slightly offset (e.g. due to floating point differences or grid alignment), consolidating them into a single clean trace aligned to their average center.

Changes

• Core Logic: Added tryCombineParallelTraces method to TraceCombineSolver.
  • Detects parallel traces (Horizontal/Vertical).
  • Checks for proximity (threshold: 0.05).
  • Merges them into a single trace aligned to the average coordinate of the two.
• Integration: Updated combineTracesForNet logic to attempt parallel merging if end-to-end connection fails.
• Tests: Added tests/reproduction_issue_34.test.ts to verify that close parallel traces are correctly merged into one.

Verification

• New Test: Verified that tests/reproduction_issue_34.test.ts passes (merges 2 close parallel traces into 1).
• Regressions: Verified that existing tests (including Issue New Phase To combine same-net trace segments that are close together #29 tests) still pass with no regressions.

Related Issue

Closes #34
/claim #34

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Project	Deployment	Review	Updated (UTC)
schematic-trace-solver	Ready	Preview, Comment	Jan 18, 2026 3:28am

[rushabhcodes]

You need to recreate an example of the problem, then show that you fixed the problem in a snapshot

[giajoe24]

@rushabhcodes
I have created a reproduction case and verified the fix.

Here is the visual proof:

Before (TraceCombineSolver input):
Two close parallel traces on the same net.

After (TraceCombineSolver output):
The traces are correctly merged into a single path.

I also verified this with a reproduction test tests/reproduction_issue_34.test.ts which now passes.