Files
kicad-mcp-server/tests/test_autoroute_score.py
NiNjA-CodE e2941631c1 feat(autoroute): add best-of-N support (attempts, targetNets, passSchedule) (#190)
The existing single-shot autoroute leaves 1-7 nets unrouted on dense
boards in my testing. Best-of-N drives that to 0 most of the time by
running Freerouting a few times with varied --max-passes and keeping
the SES with the best routing score.

New optional parameters (all backward-compatible):

  attempts:     int, default 1 (unchanged behaviour). When > 1, run
                Freerouting N times and pick the highest-scoring SES.
  targetNets:   list of critical net names. An attempt that routes all
                of them earns a 50,000-point scoring bonus.
  passSchedule: list of --max-passes values to cycle through across
                attempts. Default: [50, 60, 65, 70, 75, 80, 85, 90, 55,
                95] (wraps if attempts > len). Ignored when attempts=1
                (legacy maxPasses still used).

Scoring contract (pinned by tests):
  score = nets_routed * 1000 + segments
  if targetNets and all routed: score += 50_000

  - +1 net always beats any segment-count delta (1000 pt step).
  - Segments break ties at equal net count.
  - Target bonus dominates net-count gains from unrelated nets.

## Implementation notes

  - When attempts > 1, each attempt runs with `-mt 1` (single-thread
    optimisation). Freerouting 2.x's multi-threaded optimiser is
    documented to introduce clearance violations, so forcing
    single-thread during scoring keeps the comparison apples-to-apples.
  - One failed attempt does not abort the whole best-of-N run. The
    failure is recorded in the response under attempts[] with ok=False,
    and the remaining attempts compete for best. If every attempt fails
    the response surfaces a clear error.
  - The winning SES is preserved as <stem>_best.ses next to the
    canonical <stem>.ses so the caller can inspect it after the run.
  - Response shape:
      attempts == 1:  unchanged (no attempts/best_attempt fields)
      attempts > 1:   adds attempts[], best_attempt, best_score,
                      best_ses_path

## Attribution

Scoring approach and default pass schedule ported from
morningfire-pcb-automation
(https://github.com/NiNjA-CodE/morningfire-pcb-automation,
scripts/routing/freeroute_runner.py). Credited in the function
docstring, the TypeScript wrapper comment, the tool description (visible
to MCP clients), and the CHANGELOG entry.

The MCP version adds: cleaner per-attempt result reporting, automatic
single-thread optimisation, graceful degradation on partial failure,
and explicit validation that surfaces clean error payloads for invalid
attempts values.

## Tests

  tests/test_autoroute_score.py             8 cases, scoring contract
  tests/test_autoroute_best_of_n.py         6 cases, orchestration logic

All 14 passing. Tests are pure-Python: subprocess is mocked so the
suite runs in any environment (no Java / Freerouting / KiCad required).

  - Single-attempt response shape unchanged
  - Best-of-three picks the highest-scoring SES
  - One nonzero exit attempt doesn't abort the run
  - passSchedule wraps when attempts exceeds len
  - targetNets bonus wins over higher raw net count
  - attempts=0 rejected with clean error before DSN export
  - +1 net (1000 pts) dominates any segment delta
  - Segments tiebreak at equal net count
  - Quoted net names in SES are normalised vs unquoted targets

TypeScript builds clean.
2026-05-18 23:03:38 -04:00

123 lines
4.5 KiB
Python

"""Tests for the best-of-N scoring in autoroute (`_score_ses`).
Best-of-N support is ported from morningfire-pcb-automation
(https://github.com/NiNjA-CodE/morningfire-pcb-automation,
scripts/routing/freeroute_runner.py::score_ses). These tests pin the
scoring contract so future changes don't silently shift the ranking.
"""
import sys
from pathlib import Path
import pytest
PYTHON_DIR = Path(__file__).parent.parent / "python"
sys.path.insert(0, str(PYTHON_DIR))
from commands.freerouting import _score_ses # noqa: E402
def _ses(nets, segments, vias=0):
"""Build a minimal SES text with the given (net, segment_count) shape.
The parser only looks at `(net NAME\n (wire` occurrences and `(wire`
/ `(via ` substrings, so a synthetic fixture is enough.
"""
chunks = []
for net, seg_count in nets:
chunks.append(f'(net "{net}"\n')
for _ in range(seg_count):
chunks.append(" (wire (path F.Cu 200 0 0 1 1))\n")
chunks.append(")\n")
# Tack on extra wires not tied to a (net ...) header — counted as
# segments but not as nets.
for _ in range(segments - sum(s for _, s in nets)):
chunks.append(" (wire (path F.Cu 200 0 0 1 1))\n")
for _ in range(vias):
chunks.append(' (via "Via[0-1]_600:300_um" 100 200)\n')
return "".join(chunks)
@pytest.mark.unit
def test_empty_ses_scores_zero():
r = _score_ses("", [])
assert r["score"] == 0
assert r["nets"] == 0
assert r["segments"] == 0
@pytest.mark.unit
def test_more_nets_always_beats_more_segments():
"""A single extra net (1000 pts) must beat any reasonable seg count delta."""
a = _score_ses(_ses([("N1", 50), ("N2", 50), ("N3", 50)], segments=150), [])
b = _score_ses(_ses([("N1", 50), ("N2", 50)], segments=999), [])
assert a["nets"] == 3 and b["nets"] == 2
assert a["score"] > b["score"], "+1 net (1000 pts) must dominate segment delta"
@pytest.mark.unit
def test_segments_break_ties_when_net_counts_equal():
a = _score_ses(_ses([("N1", 10), ("N2", 10)], segments=20), [])
b = _score_ses(_ses([("N1", 30), ("N2", 30)], segments=60), [])
assert a["nets"] == b["nets"] == 2
assert b["score"] > a["score"], "more segments breaks tie when net counts equal"
@pytest.mark.unit
def test_target_bonus_dominates_when_all_targets_routed():
"""The 50,000-point bonus must outweigh marginal nets/segments differences."""
# `with_targets` has the targets but fewer overall nets.
with_targets = _score_ses(
_ses([("CRITICAL_A", 10), ("CRITICAL_B", 10)], segments=20),
target_nets=["CRITICAL_A", "CRITICAL_B"],
)
# `without_targets` has more nets but is missing one target.
without_targets = _score_ses(
_ses([
("CRITICAL_A", 10),
("OTHER1", 10), ("OTHER2", 10), ("OTHER3", 10),
("OTHER4", 10), ("OTHER5", 10), ("OTHER6", 10),
], segments=70),
target_nets=["CRITICAL_A", "CRITICAL_B"],
)
assert without_targets["targets_missing"] == ["CRITICAL_B"]
assert with_targets["targets_missing"] == []
assert with_targets["score"] > without_targets["score"], (
"all-targets bonus must beat marginal net-count gain"
)
@pytest.mark.unit
def test_target_bonus_inactive_when_targets_unspecified():
"""No targets configured -> score == nets*1000 + segments (no bonus)."""
r = _score_ses(_ses([("X", 5)], segments=5), [])
assert r["score"] == 1000 + 5
assert r["targets_found"] == [] and r["targets_missing"] == []
@pytest.mark.unit
def test_quoted_net_names_in_ses_are_normalised():
"""Freerouting writes nets as `(net "X"` — surrounding quotes must be stripped."""
text = '(net "MY_NET"\n (wire (path F.Cu 200 0 0 1 1))\n)\n'
r = _score_ses(text, target_nets=["MY_NET"])
assert r["targets_missing"] == [], "quoted net name should match unquoted target"
assert r["targets_found"] == ["MY_NET"]
@pytest.mark.unit
def test_targets_missing_and_found_are_sorted_for_stable_output():
text = _ses(
[("Z_NET", 1), ("A_NET", 1), ("M_NET", 1)],
segments=3,
)
r = _score_ses(text, target_nets=["Z_NET", "A_NET", "MISSING_X", "MISSING_A"])
assert r["targets_found"] == ["A_NET", "Z_NET"]
assert r["targets_missing"] == ["MISSING_A", "MISSING_X"]
@pytest.mark.unit
def test_via_count_is_reported_independently_of_score():
r = _score_ses(_ses([("X", 2)], segments=2, vias=7), [])
assert r["vias"] == 7
# Score formula does NOT include vias by design.
assert r["score"] == 1 * 1000 + 2