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fix: ERC handler fails on KiCad 9 schematics

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Two issues with run_erc on KiCad 9:

1. kicad-cli returns non-zero exit code when ERC violations exist.
   The handler treated this as a command failure and returned early
   with success=false, even though valid JSON output was produced.
   Fix: check for output file existence instead of exit code.

2. KiCad 9 nests violations under sheets[].violations instead of
   (or in addition to) the top-level violations[] array used by
   KiCad 8. The handler only read the top-level array, reporting
   0 violations on schematics with sub-sheets.
   Fix: iterate sheets[] and collect all nested violations.

Both fixes are backward-compatible with KiCad 8.

6 unit tests added covering non-zero exit codes, KiCad 8 top-level
violations, KiCad 9 sheets[] nesting, mixed structures, zero
violations, and missing output files.
This commit is contained in:
Leah Armstrong
2026-04-14 12:52:17 -04:00
parent eea43d18f1
commit 15d06e449a
2 changed files with 262 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

18
python/kicad_interface.py
View File

@@ -2664,11 +2664,14 @@ class KiCADInterface:
result = subprocess.run(cmd, capture_output=True, text=True, timeout=120)
if result.returncode != 0:
logger.error(f"ERC command failed: {result.stderr}")
# kicad-cli returns non-zero when ERC violations are found —
# this is normal, not an error. Only fail when no JSON was
# produced (genuine CLI failure).
if not os.path.exists(json_output) or os.path.getsize(json_output) == 0:
logger.error(f"ERC command produced no output: {result.stderr}")
return {
"success": False,
"message": "ERC command failed",
"message": "ERC command failed - no output produced",
"errorDetails": result.stderr,
}
@@ -2678,7 +2681,14 @@ class KiCADInterface:
violations = []
severity_counts = {"error": 0, "warning": 0, "info": 0}
for v in erc_data.get("violations", []):
# KiCad 9 nests violations under sheets[].violations
# instead of (or in addition to) the top-level violations
# array used by KiCad 8.
all_violations = erc_data.get("violations", [])
for sheet in erc_data.get("sheets", []):
all_violations.extend(sheet.get("violations", []))
for v in all_violations:
vseverity = v.get("severity", "error")
items = v.get("items", [])
loc = {}

248
tests/test_erc_handler.py Normal file
View File

@@ -0,0 +1,248 @@
"""
Tests for run_erc handler.
Covers:
- Non-zero exit code acceptance (kicad-cli returns non-zero when violations exist)
- KiCad 9 sheets[].violations JSON structure parsing
- KiCad 8 top-level violations[] JSON structure (backward compat)
- Missing/empty output file handling
"""
import json
import sys
from pathlib import Path
from typing import Any
from unittest.mock import MagicMock, patch
import pytest
sys.path.insert(0, str(Path(__file__).parent.parent / "python"))
# ---------------------------------------------------------------------------
# Shared fixture: KiCADInterface instance (no __init__, avoids pcbnew/IPC)
# ---------------------------------------------------------------------------
def _make_iface() -> Any:
with patch("kicad_interface.USE_IPC_BACKEND", False):
from kicad_interface import KiCADInterface
iface = KiCADInterface.__new__(KiCADInterface)
return iface
@pytest.fixture()
def iface():
return _make_iface()
# ---------------------------------------------------------------------------
# Sample ERC JSON outputs
# ---------------------------------------------------------------------------
# KiCad 8 style: violations at top level
_ERC_KICAD8_JSON = {
"violations": [
{
"type": "pin_not_connected",
"severity": "error",
"description": "Pin not connected",
"items": [{"pos": {"x": 100.0, "y": 50.0}}],
},
{
"type": "wire_dangling",
"severity": "warning",
"description": "Wire end not connected",
"items": [{"pos": {"x": 200.0, "y": 75.0}}],
},
]
}
# KiCad 9 style: violations nested under sheets[]
_ERC_KICAD9_JSON = {
"violations": [],
"sheets": [
{
"path": "/",
"violations": [
{
"type": "pin_not_connected",
"severity": "error",
"description": "Pin not connected",
"items": [{"pos": {"x": 10.0, "y": 20.0}}],
},
],
},
{
"path": "/sub-sheet-1",
"violations": [
{
"type": "label_dangling",
"severity": "error",
"description": "Label not connected to anything",
"items": [{"pos": {"x": 30.0, "y": 40.0}}],
},
{
"type": "wire_dangling",
"severity": "warning",
"description": "Wire end not connected",
"items": [{"pos": {"x": 50.0, "y": 60.0}}],
},
],
},
],
}
# KiCad 9 with violations in both top-level and sheets (edge case)
_ERC_MIXED_JSON = {
"violations": [
{
"type": "power_pin_not_driven",
"severity": "error",
"description": "Power pin not driven",
"items": [{"pos": {"x": 1.0, "y": 2.0}}],
},
],
"sheets": [
{
"path": "/sub",
"violations": [
{
"type": "pin_not_connected",
"severity": "error",
"description": "Pin not connected",
"items": [{"pos": {"x": 3.0, "y": 4.0}}],
},
],
},
],
}
def _mock_erc_run(erc_json: dict, returncode: int = 1):
"""Create a mock subprocess.run that writes ERC JSON to the output file."""
def _side_effect(cmd, **kwargs):
# Find the output path from the command args (--output <path>)
output_idx = cmd.index("--output") + 1
output_path = cmd[output_idx]
with open(output_path, "w") as f:
json.dump(erc_json, f)
result = MagicMock()
result.returncode = returncode
result.stderr = ""
return result
return _side_effect
def _mock_erc_no_output(returncode: int = 2):
"""Create a mock subprocess.run that produces no output file."""
def _side_effect(cmd, **kwargs):
result = MagicMock()
result.returncode = returncode
result.stderr = "kicad-cli: error: schematic not found"
return result
return _side_effect
# ===========================================================================
# Tests
# ===========================================================================
@pytest.mark.unit
class TestERCNonZeroExitCode:
"""kicad-cli returns non-zero when violations exist — this is not an error."""
def test_nonzero_returncode_with_valid_json_succeeds(self, iface, tmp_path):
sch = tmp_path / "test.kicad_sch"
sch.write_text("(kicad_sch)")
iface.design_rule_commands = MagicMock()
iface.design_rule_commands._find_kicad_cli.return_value = "/usr/bin/kicad-cli"
with patch("subprocess.run", side_effect=_mock_erc_run(_ERC_KICAD8_JSON, returncode=1)):
result = iface._handle_run_erc({"schematicPath": str(sch)})
assert result["success"] is True
assert "2 violation" in result["message"]
def test_zero_returncode_no_violations(self, iface, tmp_path):
sch = tmp_path / "test.kicad_sch"
sch.write_text("(kicad_sch)")
iface.design_rule_commands = MagicMock()
iface.design_rule_commands._find_kicad_cli.return_value = "/usr/bin/kicad-cli"
with patch("subprocess.run", side_effect=_mock_erc_run({"violations": []}, returncode=0)):
result = iface._handle_run_erc({"schematicPath": str(sch)})
assert result["success"] is True
assert "0 violation" in result["message"]
def test_no_output_file_fails(self, iface, tmp_path):
sch = tmp_path / "test.kicad_sch"
sch.write_text("(kicad_sch)")
iface.design_rule_commands = MagicMock()
iface.design_rule_commands._find_kicad_cli.return_value = "/usr/bin/kicad-cli"
with patch("subprocess.run", side_effect=_mock_erc_no_output()):
result = iface._handle_run_erc({"schematicPath": str(sch)})
assert result["success"] is False
assert "no output" in result["message"].lower()
@pytest.mark.unit
class TestERCKicad9SheetsViolations:
"""KiCad 9 nests violations under sheets[].violations."""
def test_kicad9_sheets_violations_collected(self, iface, tmp_path):
sch = tmp_path / "test.kicad_sch"
sch.write_text("(kicad_sch)")
iface.design_rule_commands = MagicMock()
iface.design_rule_commands._find_kicad_cli.return_value = "/usr/bin/kicad-cli"
with patch("subprocess.run", side_effect=_mock_erc_run(_ERC_KICAD9_JSON)):
result = iface._handle_run_erc({"schematicPath": str(sch)})
assert result["success"] is True
assert "3 violation" in result["message"]
assert result["summary"]["by_severity"]["error"] == 2
assert result["summary"]["by_severity"]["warning"] == 1
def test_kicad8_top_level_violations_still_work(self, iface, tmp_path):
sch = tmp_path / "test.kicad_sch"
sch.write_text("(kicad_sch)")
iface.design_rule_commands = MagicMock()
iface.design_rule_commands._find_kicad_cli.return_value = "/usr/bin/kicad-cli"
with patch("subprocess.run", side_effect=_mock_erc_run(_ERC_KICAD8_JSON)):
result = iface._handle_run_erc({"schematicPath": str(sch)})
assert result["success"] is True
assert "2 violation" in result["message"]
assert result["summary"]["by_severity"]["error"] == 1
assert result["summary"]["by_severity"]["warning"] == 1
def test_mixed_top_level_and_sheets_violations(self, iface, tmp_path):
sch = tmp_path / "test.kicad_sch"
sch.write_text("(kicad_sch)")
iface.design_rule_commands = MagicMock()
iface.design_rule_commands._find_kicad_cli.return_value = "/usr/bin/kicad-cli"
with patch("subprocess.run", side_effect=_mock_erc_run(_ERC_MIXED_JSON)):
result = iface._handle_run_erc({"schematicPath": str(sch)})
assert result["success"] is True
# 1 top-level + 1 from sheets = 2 total
assert "2 violation" in result["message"]
assert result["summary"]["by_severity"]["error"] == 2