Fix: preserve nested enclosing connection cycles

[Abse2001]

Prerequisite

• Simplify TIDA-01389 enclosing-cycle repro #986 — minimal six-component repro (merged)

TI reference

This routing case is reduced from TIDA-01389 — Small-Footprint Sunroof Motor Module Reference Design, a TI 15-A automotive motor-control module for sunroof and window-lift applications. The design uses a DRV8703-Q1 H-bridge gate driver with two dual-package automotive MOSFETs.

The minimal repro isolates the H-bridge power-stage topology from the official TIDA-01389 schematic (TIDRQE4): Q1A, Q1B, Q2A, and Q2B form the outer bridge loop, while C17 and C18 form the nested branch. All control, sensing, protection, and unrelated power components were removed from the repro.

Original TI H-bridge schematic

This excerpt shows only the original H-bridge power stage, including the outer Q1/Q2 bridge and the nested C17/C18 branch used by the repro.

Summary

• add a dedicated post-MSP pipeline stage for nested enclosing connection cycles
• detect a four-component perimeter using connectivity, distinct corner pins, polygon enclosure, and an inner two-net branch tied to perimeter nets
• restore the authored acyclic connection tree only for affected perimeter nets while retaining normal MSP fallback pairs for every other net
• leave the general MSP and trace-routing algorithms unchanged; non-matching layouts are an exact no-op
• restore both outer side rails in the minimal repro while keeping the C17/C18 inner rectangle connected

This PR contains only the solver fix, its stage tests, and the expected result changes for the merged minimal repro. The earlier snapshot-converter and full 18-component fixture changes are not included.

Snapshots

Before — merged minimal repro

The two outer side rails are dropped and replaced by routes through the nested branch.

After — this PR

The outer rectangle is preserved while the C17/C18 inner rectangle remains connected.

Regression coverage

• the minimal repro verifies all four outer edges and both inner capacitor-net edges survive pairing
• final-route assertions verify the left and right rails stay on their outer columns
• a deliberately skewed enclosure verifies detection is independent of rectangle alignment and pin direction
• an enclosure without the nested two-net topology verifies geometry alone does not trigger the stage
• an ordinary non-enclosing case verifies MSP pairs and visualization remain unchanged

Verification

• bun test tests/repros/repro-tida-01389-hbridge.test.ts tests/solvers/EnclosingCycleConnectionPairSolver/EnclosingCycleConnectionPairSolver.test.ts
• bunx tsc --noEmit
• bun run format:check
• bun test — 291 passed, 4 skipped, 0 failed

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
schematic-trace-solver	Ready	Preview	Aug 30, 2026 11:19pm

[seveibar]

Can you fix the circuit json display before this? Not sure what I’m looking at

[Abse2001]

Addressed in 79276a9. The Circuit JSON panel now uses semantic refdes/net metadata and native MOSFET, resistor, and capacitor symbols, so the H-bridge topology is readable without exposing opaque solver IDs. Component coordinates, connectivity, and solver routing input are unchanged. I also added a focused check that explicit multi-pin symbols are only rendered when every pin maps consistently. Verified with the focused tests, typecheck, formatter, and the full suite (291 pass, 4 skip).

[Abse2001]

Split and cleaned as requested. The standalone six-component failing repro is now #986. This PR is stacked on that branch and now contains only the post-MSP solver stage, focused stage coverage, and the minimal fixed snapshot/assertions. The previous snapshot-converter commit and full 18-component fixture changes were removed.

[Abse2001]

Rebased onto main after #986 merged. The PR is again a single fix commit and its diff remains limited to the solver stage, pipeline insertion, focused stage/repro assertions, and fixed minimal snapshot. Local focused tests, typecheck, formatting, and full suite all pass.