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Compare two test262 result files to find exactly which tests changed status. Use after a test262 run shows unexpected pass count changes.
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Compile a source file to WAT and analyze the output for codegen inefficiencies. Use after a codegen change to verify the output is clean, when investigating performance issues, or when creating optimization issues from real compiler output.
Write an implementation spec for a hard issue. Read compiler source, identify exact functions/lines, design the fix, document edge cases.
Quickly find which commit introduced a test262 regression using git bisect with automated test.
Atomically claim an issue for a developer (human or agent) via the cross-developer lock ref, so two devs never pick up the same task. Syncs with origin first, refuses if already claimed or already done on main, and pushes the claim immediately without touching main or triggering CI.
Create a new issue file from a test262 failure pattern. Includes smoke test, sample extraction, and proper frontmatter.
Merge self-check for a green PR. Reads the PR's required-check status from the checks API (the committed ci-status feed is RETIRED), outputs MERGE (mark task completed, stand down — server-side auto-enqueue enqueues,
| name | analyze-regression |
| description | Compare two test262 result files to find exactly which tests changed status. Use after a test262 run shows unexpected pass count changes. |
Diffs two test262 JSONL result files to find exactly which tests flipped status.
ls -lt /workspace/benchmarks/results/test262-results*.jsonl | head -10
CURRENT="/workspace/benchmarks/results/test262-results.jsonl"
PREVIOUS="/workspace/benchmarks/results/test262-results-YYYYMMDD-HHMMSS.jsonl"
python3 -c "
import json
from collections import Counter
current, previous = {}, {}
with open('$CURRENT') as f:
for line in f:
r = json.loads(line)
current[r['file']] = r['status']
with open('$PREVIOUS') as f:
for line in f:
r = json.loads(line)
previous[r['file']] = r['status']
# Find flips
regressions = [] # was pass, now not
fixes = [] # was not pass, now pass
for test in set(current) | set(previous):
old = previous.get(test, 'missing')
new = current.get(test, 'missing')
if old == 'pass' and new != 'pass':
regressions.append((test, old, new))
elif old != 'pass' and new == 'pass':
fixes.append((test, old, new))
print(f'Regressions (pass→fail): {len(regressions)}')
for t, o, n in sorted(regressions)[:20]:
print(f' {n:15s} ← {o:15s} {t}')
if len(regressions) > 20:
print(f' ... and {len(regressions)-20} more')
print(f'\nFixes (fail→pass): {len(fixes)}')
for t, o, n in sorted(fixes)[:20]:
print(f' {n:15s} ← {o:15s} {t}')
if len(fixes) > 20:
print(f' ... and {len(fixes)-20} more')
# Categorize regressions by new status
regr_cats = Counter(n for _, _, n in regressions)
print(f'\nRegression breakdown: {dict(regr_cats)}')
"
Message with: "Regression analysis: +N fixes, -M regressions. Top pattern: [description]"