Understand the failure.
Verify the repair.
Small, reproducible software failures. The broken implementation, the fix that didn’t work, and the one that passed—preserved together.
Explore the cases ↓How results are verified ↗WHAT THE ARCHIVE CONTAINS
100840 executable cases. 20168 are open.
Every case records the implementation that fails, the fix that did not work, and the repair that passed its checks—with recorded outputs and source hashes. This release adds 100840 cases across 20168 failure mechanisms and 254 domains.
The open tier gives you the failure and the unsuccessful fix for one case in every mechanism. The remaining 80672 cases, 5 variants per mechanism, are member-only: the verified repair, its recorded checks, and the full fixture suite are held in the member archive. Read the methodology ↗
A RECORD OF WHAT WENT WRONG
Browse the archive / 100840
Multi-state wage allocation by work days: remainder ranking · case 01
Leftover cents go to the states with the most days instead of the largest fractional shares.
Multi-state wage allocation by work days: remainder ranking · case 02
Leftover cents go to the states with the most days instead of the largest fractional shares.
Multi-state wage allocation by work days: remainder ranking · case 03
Leftover cents go to the states with the most days instead of the largest fractional shares.
Multi-state wage allocation by work days: remainder ranking · case 04
Leftover cents go to the states with the most days instead of the largest fractional shares.
Multi-state wage allocation by work days: remainder ranking · case 05
Leftover cents go to the states with the most days instead of the largest fractional shares.
Multi-state wage allocation by work days: leftover distribution · case 01
All leftover cents land in a single state.
Multi-state wage allocation by work days: leftover distribution · case 02
All leftover cents land in a single state.
Multi-state wage allocation by work days: leftover distribution · case 03
All leftover cents land in a single state.
Multi-state wage allocation by work days: leftover distribution · case 04
All leftover cents land in a single state.
Multi-state wage allocation by work days: leftover distribution · case 05
All leftover cents land in a single state.
Multi-state wage allocation by work days: base order tie-break · case 01
Which state receives a tied leftover cent depends on dictionary insertion order.
Multi-state wage allocation by work days: base order tie-break · case 02
Which state receives a tied leftover cent depends on dictionary insertion order.
Multi-state wage allocation by work days: base order tie-break · case 03
Which state receives a tied leftover cent depends on dictionary insertion order.
Multi-state wage allocation by work days: base order tie-break · case 04
Which state receives a tied leftover cent depends on dictionary insertion order.
Multi-state wage allocation by work days: base order tie-break · case 05
Which state receives a tied leftover cent depends on dictionary insertion order.
Multi-state wage allocation by work days: zero allocation filter · case 01
Allocation results list states with zero cents allocated.
Multi-state wage allocation by work days: zero allocation filter · case 02
Allocation results list states with zero cents allocated.
Multi-state wage allocation by work days: zero allocation filter · case 03
Allocation results list states with zero cents allocated.
Multi-state wage allocation by work days: zero allocation filter · case 04
Allocation results list states with zero cents allocated.
Multi-state wage allocation by work days: zero allocation filter · case 05
Allocation results list states with zero cents allocated.
Pay dates in a calendar year: first pay date ceiling · case 01
The first pay date reported for a year falls in December of the prior year.
Pay dates in a calendar year: first pay date ceiling · case 02
The first pay date reported for a year falls in December of the prior year.
Pay dates in a calendar year: first pay date ceiling · case 03
The first pay date reported for a year falls in December of the prior year.
Pay dates in a calendar year: first pay date ceiling · case 04
The first pay date reported for a year falls in December of the prior year.
Pay dates in a calendar year: first pay date ceiling · case 05
The first pay date reported for a year falls in December of the prior year.
Pay dates in a calendar year: inclusive end count · case 01
Every year shows one pay date fewer than the payroll calendar.
Pay dates in a calendar year: inclusive end count · case 02
Every year shows one pay date fewer than the payroll calendar.
Pay dates in a calendar year: inclusive end count · case 03
Every year shows one pay date fewer than the payroll calendar.
Pay dates in a calendar year: inclusive end count · case 04
Every year shows one pay date fewer than the payroll calendar.
Pay dates in a calendar year: inclusive end count · case 05
Every year shows one pay date fewer than the payroll calendar.
Pay dates in a calendar year: year end date · case 01
In leap years a December 31 pay date is left out of the count.
Pay dates in a calendar year: year end date · case 02
In leap years a December 31 pay date is left out of the count.
Pay dates in a calendar year: year end date · case 03
In leap years a December 31 pay date is left out of the count.
Pay dates in a calendar year: year end date · case 04
In leap years a December 31 pay date is left out of the count.
Pay dates in a calendar year: year end date · case 05
In leap years a December 31 pay date is left out of the count.
Pay dates in a calendar year: extra period flag · case 01
Normal years are flagged as having an extra pay period.
Pay dates in a calendar year: extra period flag · case 02
Normal years are flagged as having an extra pay period.
Pay dates in a calendar year: extra period flag · case 03
Normal years are flagged as having an extra pay period.
Pay dates in a calendar year: extra period flag · case 04
Normal years are flagged as having an extra pay period.
Pay dates in a calendar year: extra period flag · case 05
Normal years are flagged as having an extra pay period.
Wage levy exempt amount: post-levy deductions excluded · case 01
Employees who enroll in new deductions after a levy shrink the levy payment.
Wage levy exempt amount: post-levy deductions excluded · case 02
Employees who enroll in new deductions after a levy shrink the levy payment.
Wage levy exempt amount: post-levy deductions excluded · case 03
Employees who enroll in new deductions after a levy shrink the levy payment.
Wage levy exempt amount: post-levy deductions excluded · case 04
Employees who enroll in new deductions after a levy shrink the levy payment.
Wage levy exempt amount: post-levy deductions excluded · case 05
Employees who enroll in new deductions after a levy shrink the levy payment.
Wage levy exempt amount: dependent count · case 01
Every levied employee receives one extra dependent exemption.
Wage levy exempt amount: dependent count · case 02
Every levied employee receives one extra dependent exemption.
Wage levy exempt amount: dependent count · case 03
Every levied employee receives one extra dependent exemption.
Wage levy exempt amount: dependent count · case 04
Every levied employee receives one extra dependent exemption.
Wage levy exempt amount: dependent count · case 05
Every levied employee receives one extra dependent exemption.
Wage levy exempt amount: exempt de-annualization · case 01
Semimonthly and monthly employees receive a smaller exempt amount than their annual figure implies.
Wage levy exempt amount: exempt de-annualization · case 02
Semimonthly and monthly employees receive a smaller exempt amount than their annual figure implies.
Wage levy exempt amount: exempt de-annualization · case 03
Semimonthly and monthly employees receive a smaller exempt amount than their annual figure implies.
Wage levy exempt amount: exempt de-annualization · case 04
Semimonthly and monthly employees receive a smaller exempt amount than their annual figure implies.
Wage levy exempt amount: exempt de-annualization · case 05
Semimonthly and monthly employees receive a smaller exempt amount than their annual figure implies.
Daily, weekly and seventh-day overtime split: seventh-day trigger · case 01
Anyone working the last day of the week gets seventh-day premium pay.
Daily, weekly and seventh-day overtime split: seventh-day trigger · case 02
Anyone working the last day of the week gets seventh-day premium pay.
Daily, weekly and seventh-day overtime split: seventh-day trigger · case 03
Anyone working the last day of the week gets seventh-day premium pay.
Daily, weekly and seventh-day overtime split: seventh-day trigger · case 04
Anyone working the last day of the week gets seventh-day premium pay.
Daily, weekly and seventh-day overtime split: seventh-day trigger · case 05
Anyone working the last day of the week gets seventh-day premium pay.
Daily, weekly and seventh-day overtime split: daily overtime window · case 01
Very long days count hours past twelve as both overtime and double time.
Daily, weekly and seventh-day overtime split: daily overtime window · case 02
Very long days count hours past twelve as both overtime and double time.
Daily, weekly and seventh-day overtime split: daily overtime window · case 03
Very long days count hours past twelve as both overtime and double time.
Daily, weekly and seventh-day overtime split: daily overtime window · case 04
Very long days count hours past twelve as both overtime and double time.
Daily, weekly and seventh-day overtime split: daily overtime window · case 05
Very long days count hours past twelve as both overtime and double time.
Daily, weekly and seventh-day overtime split: weekly regular-hour room · case 01
Employees with daily overtime early in the week hit weekly overtime too soon.
Daily, weekly and seventh-day overtime split: weekly regular-hour room · case 02
Employees with daily overtime early in the week hit weekly overtime too soon.
Daily, weekly and seventh-day overtime split: weekly regular-hour room · case 03
Employees with daily overtime early in the week hit weekly overtime too soon.
Daily, weekly and seventh-day overtime split: weekly regular-hour room · case 04
Employees with daily overtime early in the week hit weekly overtime too soon.
Daily, weekly and seventh-day overtime split: weekly regular-hour room · case 05
Employees with daily overtime early in the week hit weekly overtime too soon.
Employment tax deposit due date: next-day threshold · case 01
Employers accumulating exactly 100,000 miss the next-day deposit.
Employment tax deposit due date: next-day threshold · case 02
Employers accumulating exactly 100,000 miss the next-day deposit.
Employment tax deposit due date: next-day threshold · case 03
Employers accumulating exactly 100,000 miss the next-day deposit.
Employment tax deposit due date: next-day threshold · case 04
Employers accumulating exactly 100,000 miss the next-day deposit.
Employment tax deposit due date: next-day threshold · case 05
Employers accumulating exactly 100,000 miss the next-day deposit.
Employment tax deposit due date: next weekday skip · case 01
Friday payday next-day deposits come due on Saturday.
Employment tax deposit due date: next weekday skip · case 02
Friday payday next-day deposits come due on Saturday.
Employment tax deposit due date: next weekday skip · case 03
Friday payday next-day deposits come due on Saturday.
Employment tax deposit due date: next weekday skip · case 04
Friday payday next-day deposits come due on Saturday.
Employment tax deposit due date: next weekday skip · case 05
Friday payday next-day deposits come due on Saturday.
Employment tax deposit due date: monthly lookback boundary · case 01
Employers with exactly 50,000 of lookback liability are put on the semiweekly schedule.
Employment tax deposit due date: monthly lookback boundary · case 02
Employers with exactly 50,000 of lookback liability are put on the semiweekly schedule.
Employment tax deposit due date: monthly lookback boundary · case 03
Employers with exactly 50,000 of lookback liability are put on the semiweekly schedule.
Employment tax deposit due date: monthly lookback boundary · case 04
Employers with exactly 50,000 of lookback liability are put on the semiweekly schedule.
Employment tax deposit due date: monthly lookback boundary · case 05
Employers with exactly 50,000 of lookback liability are put on the semiweekly schedule.
Employment tax deposit due date: December rollover · case 01
December monthly deposits are dated January of the same year.
Employment tax deposit due date: December rollover · case 02
December monthly deposits are dated January of the same year.
Employment tax deposit due date: December rollover · case 03
December monthly deposits are dated January of the same year.
Employment tax deposit due date: December rollover · case 04
December monthly deposits are dated January of the same year.
Employment tax deposit due date: December rollover · case 05
December monthly deposits are dated January of the same year.
Employment tax deposit due date: semiweekly Wednesday group · case 01
Wednesday paydays show the deposit due the same day.
Employment tax deposit due date: semiweekly Wednesday group · case 02
Wednesday paydays show the deposit due the same day.
Employment tax deposit due date: semiweekly Wednesday group · case 03
Wednesday paydays show the deposit due the same day.
Employment tax deposit due date: semiweekly Wednesday group · case 04
Wednesday paydays show the deposit due the same day.
Employment tax deposit due date: semiweekly Wednesday group · case 05
Wednesday paydays show the deposit due the same day.
Tip shortfall allocation by hours: proportional allocation · case 01
Allocated tips add up to more than the establishment shortfall.
Tip shortfall allocation by hours: proportional allocation · case 02
Allocated tips add up to more than the establishment shortfall.
Tip shortfall allocation by hours: proportional allocation · case 03
Allocated tips add up to more than the establishment shortfall.
Tip shortfall allocation by hours: proportional allocation · case 04
Allocated tips add up to more than the establishment shortfall.
Tip shortfall allocation by hours: proportional allocation · case 05
Allocated tips add up to more than the establishment shortfall.
INSPECTABLE BY DESIGN
Every result has a runnable source.
Runnable implementations with recorded outputs, source hashes, and explicit contracts. Related variants share a failure mechanism and belong together in evaluation splits.
Read the methodology ↗