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
Usage tiers after a prorated included allowance: covered usage short-circuit · case 01
Customers whose usage is fully covered by the allowance are billed a tier flat fee.
Usage tiers after a prorated included allowance: covered usage short-circuit · case 02
Customers whose usage is fully covered by the allowance are billed a tier flat fee.
Usage tiers after a prorated included allowance: covered usage short-circuit · case 03
Customers whose usage is fully covered by the allowance are billed a tier flat fee.
Usage tiers after a prorated included allowance: covered usage short-circuit · case 04
Customers whose usage is fully covered by the allowance are billed a tier flat fee.
Usage tiers after a prorated included allowance: covered usage short-circuit · case 05
Customers whose usage is fully covered by the allowance are billed a tier flat fee.
Prorated amounts in currency minor units: zero-exponent display · case 01
Chilean peso invoices print a decimal point and a stray digit.
Prorated amounts in currency minor units: zero-exponent display · case 02
Chilean peso invoices print a decimal point and a stray digit.
Prorated amounts in currency minor units: zero-exponent display · case 03
Chilean peso invoices print a decimal point and a stray digit.
Prorated amounts in currency minor units: zero-exponent display · case 04
Chilean peso invoices print a decimal point and a stray digit.
Prorated amounts in currency minor units: zero-exponent display · case 05
Chilean peso invoices print a decimal point and a stray digit.
Prorated amounts in currency minor units: fraction zero padding · case 01
Amounts like 12.05 display as 12.5.
Prorated amounts in currency minor units: fraction zero padding · case 02
Amounts like 12.05 display as 12.5.
Prorated amounts in currency minor units: fraction zero padding · case 03
Amounts like 12.05 display as 12.5.
Prorated amounts in currency minor units: fraction zero padding · case 04
Amounts like 12.05 display as 12.5.
Prorated amounts in currency minor units: fraction zero padding · case 05
Amounts like 12.05 display as 12.5.
Prorated amounts in currency minor units: credit rounding direction · case 01
Credit prorations of exactly half a minor unit round toward zero while debits round away.
Prorated amounts in currency minor units: credit rounding direction · case 02
Credit prorations of exactly half a minor unit round toward zero while debits round away.
Prorated amounts in currency minor units: credit rounding direction · case 03
Credit prorations of exactly half a minor unit round toward zero while debits round away.
Prorated amounts in currency minor units: credit rounding direction · case 04
Credit prorations of exactly half a minor unit round toward zero while debits round away.
Prorated amounts in currency minor units: credit rounding direction · case 05
Credit prorations of exactly half a minor unit round toward zero while debits round away.
Prorated amounts in currency minor units: negative display split · case 01
Negative prorations display garbled amounts such as --2.50.
Prorated amounts in currency minor units: negative display split · case 02
Negative prorations display garbled amounts such as --2.50.
Prorated amounts in currency minor units: negative display split · case 03
Negative prorations display garbled amounts such as --2.50.
Prorated amounts in currency minor units: negative display split · case 04
Negative prorations display garbled amounts such as --2.50.
Prorated amounts in currency minor units: negative display split · case 05
Negative prorations display garbled amounts such as --2.50.
Sales tax on proration credit and debit lines: credit line tax reversal · case 01
Downgrade invoices over-collect tax because unused-time credits carry no tax reversal.
Sales tax on proration credit and debit lines: credit line tax reversal · case 02
Downgrade invoices over-collect tax because unused-time credits carry no tax reversal.
Sales tax on proration credit and debit lines: credit line tax reversal · case 03
Downgrade invoices over-collect tax because unused-time credits carry no tax reversal.
Sales tax on proration credit and debit lines: credit line tax reversal · case 04
Downgrade invoices over-collect tax because unused-time credits carry no tax reversal.
Sales tax on proration credit and debit lines: credit line tax reversal · case 05
Downgrade invoices over-collect tax because unused-time credits carry no tax reversal.
Sales tax on proration credit and debit lines: per-line tax rounding · case 01
Invoice tax differs by a cent from the sum of the per-line tax amounts shown.
Sales tax on proration credit and debit lines: per-line tax rounding · case 02
Invoice tax differs by a cent from the sum of the per-line tax amounts shown.
Sales tax on proration credit and debit lines: per-line tax rounding · case 03
Invoice tax differs by a cent from the sum of the per-line tax amounts shown.
Sales tax on proration credit and debit lines: per-line tax rounding · case 04
Invoice tax differs by a cent from the sum of the per-line tax amounts shown.
Sales tax on proration credit and debit lines: per-line tax rounding · case 05
Invoice tax differs by a cent from the sum of the per-line tax amounts shown.
Sales tax on proration credit and debit lines: subtotal composition · case 01
Non-taxable lines disappear from the invoice subtotal.
Sales tax on proration credit and debit lines: subtotal composition · case 02
Non-taxable lines disappear from the invoice subtotal.
Sales tax on proration credit and debit lines: subtotal composition · case 03
Non-taxable lines disappear from the invoice subtotal.
Sales tax on proration credit and debit lines: subtotal composition · case 04
Non-taxable lines disappear from the invoice subtotal.
Sales tax on proration credit and debit lines: subtotal composition · case 05
Non-taxable lines disappear from the invoice subtotal.
Annual-to-monthly switch credit: partial month counted as used · case 01
Customers switching mid-month are credited for the month they are already using.
Annual-to-monthly switch credit: partial month counted as used · case 02
Customers switching mid-month are credited for the month they are already using.
Annual-to-monthly switch credit: partial month counted as used · case 03
Customers switching mid-month are credited for the month they are already using.
Annual-to-monthly switch credit: partial month counted as used · case 04
Customers switching mid-month are credited for the month they are already using.
Annual-to-monthly switch credit: partial month counted as used · case 05
Customers switching mid-month are credited for the month they are already using.
Annual-to-monthly switch credit: started month cap · case 01
Customers switching after the annual term produce a negative credit.
Annual-to-monthly switch credit: started month cap · case 02
Customers switching after the annual term produce a negative credit.
Annual-to-monthly switch credit: started month cap · case 03
Customers switching after the annual term produce a negative credit.
Annual-to-monthly switch credit: started month cap · case 04
Customers switching after the annual term produce a negative credit.
Annual-to-monthly switch credit: started month cap · case 05
Customers switching after the annual term produce a negative credit.
Annual-to-monthly switch credit: credit division order · case 01
Credits for annual prices not divisible by twelve lose cents per month.
Annual-to-monthly switch credit: credit division order · case 02
Credits for annual prices not divisible by twelve lose cents per month.
Annual-to-monthly switch credit: credit division order · case 03
Credits for annual prices not divisible by twelve lose cents per month.
Annual-to-monthly switch credit: credit division order · case 04
Credits for annual prices not divisible by twelve lose cents per month.
Annual-to-monthly switch credit: credit division order · case 05
Credits for annual prices not divisible by twelve lose cents per month.
Annual-to-monthly switch credit: fully covered invoice count · case 01
A partially funded monthly invoice is reported as covered and the leftover balance goes negative.
Annual-to-monthly switch credit: fully covered invoice count · case 02
A partially funded monthly invoice is reported as covered and the leftover balance goes negative.
Annual-to-monthly switch credit: fully covered invoice count · case 03
A partially funded monthly invoice is reported as covered and the leftover balance goes negative.
Annual-to-monthly switch credit: fully covered invoice count · case 04
A partially funded monthly invoice is reported as covered and the leftover balance goes negative.
Annual-to-monthly switch credit: fully covered invoice count · case 05
A partially funded monthly invoice is reported as covered and the leftover balance goes negative.
Credit notes and customer balance on an invoice: excess credit note to balance · case 01
Credit notes larger than the invoice lose their excess value.
Credit notes and customer balance on an invoice: excess credit note to balance · case 02
Credit notes larger than the invoice lose their excess value.
Credit notes and customer balance on an invoice: excess credit note to balance · case 03
Credit notes larger than the invoice lose their excess value.
Credit notes and customer balance on an invoice: excess credit note to balance · case 04
Credit notes larger than the invoice lose their excess value.
Credit notes and customer balance on an invoice: excess credit note to balance · case 05
Credit notes larger than the invoice lose their excess value.
Credit notes and customer balance on an invoice: balance application cap · case 01
Customers with large balances see negative amounts due and a drained balance.
Credit notes and customer balance on an invoice: balance application cap · case 02
Customers with large balances see negative amounts due and a drained balance.
Credit notes and customer balance on an invoice: balance application cap · case 03
Customers with large balances see negative amounts due and a drained balance.
Credit notes and customer balance on an invoice: balance application cap · case 04
Customers with large balances see negative amounts due and a drained balance.
Credit notes and customer balance on an invoice: balance application cap · case 05
Customers with large balances see negative amounts due and a drained balance.
Credit notes and customer balance on an invoice: minimum payment deferral · case 01
Amounts exactly equal to the minimum payment are deferred.
Credit notes and customer balance on an invoice: minimum payment deferral · case 02
Amounts exactly equal to the minimum payment are deferred.
Credit notes and customer balance on an invoice: minimum payment deferral · case 03
Amounts exactly equal to the minimum payment are deferred.
Credit notes and customer balance on an invoice: minimum payment deferral · case 04
Amounts exactly equal to the minimum payment are deferred.
Credit notes and customer balance on an invoice: minimum payment deferral · case 05
Amounts exactly equal to the minimum payment are deferred.
Credit notes and customer balance on an invoice: remaining balance update · case 01
Customer balances after invoicing are wrong whenever credit notes were applied.
Credit notes and customer balance on an invoice: remaining balance update · case 02
Customer balances after invoicing are wrong whenever credit notes were applied.
Credit notes and customer balance on an invoice: remaining balance update · case 03
Customer balances after invoicing are wrong whenever credit notes were applied.
Credit notes and customer balance on an invoice: remaining balance update · case 04
Customer balances after invoicing are wrong whenever credit notes were applied.
Credit notes and customer balance on an invoice: remaining balance update · case 05
Customer balances after invoicing are wrong whenever credit notes were applied.
Dunning retry schedule and status: retry exhaustion · case 01
Subscriptions are canceled before the last scheduled retry runs.
Dunning retry schedule and status: retry exhaustion · case 02
Subscriptions are canceled before the last scheduled retry runs.
Dunning retry schedule and status: retry exhaustion · case 03
Subscriptions are canceled before the last scheduled retry runs.
Dunning retry schedule and status: retry exhaustion · case 04
Subscriptions are canceled before the last scheduled retry runs.
Dunning retry schedule and status: retry exhaustion · case 05
Subscriptions are canceled before the last scheduled retry runs.
Dunning retry schedule and status: retry offset base · case 01
Retries drift later with every failure.
Dunning retry schedule and status: retry offset base · case 02
Retries drift later with every failure.
Dunning retry schedule and status: retry offset base · case 03
Retries drift later with every failure.
Dunning retry schedule and status: retry offset base · case 04
Retries drift later with every failure.
Dunning retry schedule and status: retry offset base · case 05
Retries drift later with every failure.
Dunning retry schedule and status: future event cutoff · case 01
Status ignores a payment or failure that happened today.
Dunning retry schedule and status: future event cutoff · case 02
Status ignores a payment or failure that happened today.
Dunning retry schedule and status: future event cutoff · case 03
Status ignores a payment or failure that happened today.
Dunning retry schedule and status: future event cutoff · case 04
Status ignores a payment or failure that happened today.
Dunning retry schedule and status: future event cutoff · case 05
Status ignores a payment or failure that happened today.
Dunning retry schedule and status: payment settles invoice · case 01
Failures logged after a successful payment put a paid subscription back into dunning.
Dunning retry schedule and status: payment settles invoice · case 02
Failures logged after a successful payment put a paid subscription back into dunning.
Dunning retry schedule and status: payment settles invoice · case 03
Failures logged after a successful payment put a paid subscription back into dunning.
Dunning retry schedule and status: payment settles invoice · case 04
Failures logged after a successful payment put a paid subscription back into dunning.
Dunning retry schedule and status: payment settles invoice · case 05
Failures logged after a successful payment put a paid subscription back into dunning.
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 ↗