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
City-state-code last line parser: spelled state names are not mapped · case 01
"FAKETOWN ZEDLAND" yields state "ZEDLAND".
City-state-code last line parser: spelled state names are not mapped · case 02
"FAKETOWN ZEDLAND" yields state "ZEDLAND".
City-state-code last line parser: spelled state names are not mapped · case 03
"FAKETOWN ZEDLAND" yields state "ZEDLAND".
City-state-code last line parser: spelled state names are not mapped · case 04
"FAKETOWN ZEDLAND" yields state "ZEDLAND".
City-state-code last line parser: spelled state names are not mapped · case 05
"FAKETOWN ZEDLAND" yields state "ZEDLAND".
City-state-code last line parser: only the last city word is kept · case 01
"NEW FAKETOWN HEIGHTS" becomes "HEIGHTS".
City-state-code last line parser: only the last city word is kept · case 02
"NEW FAKETOWN HEIGHTS" becomes "HEIGHTS".
City-state-code last line parser: only the last city word is kept · case 03
"NEW FAKETOWN HEIGHTS" becomes "HEIGHTS".
City-state-code last line parser: only the last city word is kept · case 04
"NEW FAKETOWN HEIGHTS" becomes "HEIGHTS".
City-state-code last line parser: only the last city word is kept · case 05
"NEW FAKETOWN HEIGHTS" becomes "HEIGHTS".
City-state-code last line parser: overlong digit runs are accepted as codes · case 01
"111019" is accepted as a postal code.
City-state-code last line parser: overlong digit runs are accepted as codes · case 02
"111019" is accepted as a postal code.
City-state-code last line parser: overlong digit runs are accepted as codes · case 03
"111019" is accepted as a postal code.
City-state-code last line parser: overlong digit runs are accepted as codes · case 04
"111019" is accepted as a postal code.
City-state-code last line parser: overlong digit runs are accepted as codes · case 05
"111019" is accepted as a postal code.
Ordinal street name normalizer: the teen exception only covers 11 to 13 exactly · case 01
"211TH" is rewritten as "211ST".
Ordinal street name normalizer: the teen exception only covers 11 to 13 exactly · case 02
"211TH" is rewritten as "211ST".
Ordinal street name normalizer: the teen exception only covers 11 to 13 exactly · case 03
"211TH" is rewritten as "211ST".
Ordinal street name normalizer: the teen exception only covers 11 to 13 exactly · case 04
"211TH" is rewritten as "211ST".
Ordinal street name normalizer: the teen exception only covers 11 to 13 exactly · case 05
"211TH" is rewritten as "211ST".
Ordinal street name normalizer: suffix lookup uses the whole number · case 01
"Twenty-First" becomes "21TH".
Ordinal street name normalizer: suffix lookup uses the whole number · case 02
"Twenty-First" becomes "21TH".
Ordinal street name normalizer: suffix lookup uses the whole number · case 03
"Twenty-First" becomes "21TH".
Ordinal street name normalizer: suffix lookup uses the whole number · case 04
"Twenty-First" becomes "21TH".
Ordinal street name normalizer: suffix lookup uses the whole number · case 05
"Twenty-First" becomes "21TH".
Ordinal street name normalizer: hyphenated compounds are left spelled out · case 01
"TWENTY-FIRST" passes through unchanged.
Ordinal street name normalizer: hyphenated compounds are left spelled out · case 02
"TWENTY-FIRST" passes through unchanged.
Ordinal street name normalizer: hyphenated compounds are left spelled out · case 03
"TWENTY-FIRST" passes through unchanged.
Ordinal street name normalizer: hyphenated compounds are left spelled out · case 04
"TWENTY-FIRST" passes through unchanged.
Ordinal street name normalizer: hyphenated compounds are left spelled out · case 05
"TWENTY-FIRST" passes through unchanged.
Ordinal street name normalizer: the unit word of a compound is read twice · case 01
"THIRTY SECOND" becomes "32ND 2ND".
Ordinal street name normalizer: the unit word of a compound is read twice · case 02
"THIRTY SECOND" becomes "32ND 2ND".
Ordinal street name normalizer: the unit word of a compound is read twice · case 03
"THIRTY SECOND" becomes "32ND 2ND".
Ordinal street name normalizer: the unit word of a compound is read twice · case 04
"THIRTY SECOND" becomes "32ND 2ND".
Ordinal street name normalizer: the unit word of a compound is read twice · case 05
"THIRTY SECOND" becomes "32ND 2ND".
Ordinal street name normalizer: only TH-suffixed numerals are corrected · case 01
"2ST" is left as typed instead of "2ND".
Ordinal street name normalizer: only TH-suffixed numerals are corrected · case 02
"2ST" is left as typed instead of "2ND".
Ordinal street name normalizer: only TH-suffixed numerals are corrected · case 03
"2ST" is left as typed instead of "2ND".
Ordinal street name normalizer: only TH-suffixed numerals are corrected · case 04
"2ST" is left as typed instead of "2ND".
Ordinal street name normalizer: only TH-suffixed numerals are corrected · case 05
"2ST" is left as typed instead of "2ND".
Delivery point check digit: a zero check digit becomes 10 · case 01
Codes whose digit sum is a multiple of ten end in "10".
Delivery point check digit: a zero check digit becomes 10 · case 02
Codes whose digit sum is a multiple of ten end in "10".
Delivery point check digit: a zero check digit becomes 10 · case 03
Codes whose digit sum is a multiple of ten end in "10".
Delivery point check digit: a zero check digit becomes 10 · case 04
Codes whose digit sum is a multiple of ten end in "10".
Delivery point check digit: a zero check digit becomes 10 · case 05
Codes whose digit sum is a multiple of ten end in "10".
Delivery point check digit: the first two house digits are used · case 01
House 123 gets delivery point 12 instead of 23.
Delivery point check digit: the first two house digits are used · case 02
House 123 gets delivery point 12 instead of 23.
Delivery point check digit: the first two house digits are used · case 03
House 123 gets delivery point 12 instead of 23.
Delivery point check digit: the first two house digits are used · case 04
House 123 gets delivery point 12 instead of 23.
Delivery point check digit: the first two house digits are used · case 05
House 123 gets delivery point 12 instead of 23.
Delivery point check digit: single-digit delivery points are not padded · case 01
House 7 contributes one digit, shortening the code.
Delivery point check digit: single-digit delivery points are not padded · case 02
House 7 contributes one digit, shortening the code.
Delivery point check digit: single-digit delivery points are not padded · case 03
House 7 contributes one digit, shortening the code.
Delivery point check digit: single-digit delivery points are not padded · case 04
House 7 contributes one digit, shortening the code.
Delivery point check digit: single-digit delivery points are not padded · case 05
House 7 contributes one digit, shortening the code.
Delivery point check digit: digits after a hyphen join the house number · case 01
"12-4" gives delivery point 24 instead of 12.
Delivery point check digit: digits after a hyphen join the house number · case 02
"12-4" gives delivery point 24 instead of 12.
Delivery point check digit: digits after a hyphen join the house number · case 03
"12-4" gives delivery point 24 instead of 12.
Delivery point check digit: digits after a hyphen join the house number · case 04
"12-4" gives delivery point 24 instead of 12.
Delivery point check digit: digits after a hyphen join the house number · case 05
"12-4" gives delivery point 24 instead of 12.
Delivery point check digit: missing house number defaults to 00 · case 01
A line without house digits gets delivery point 00.
Delivery point check digit: missing house number defaults to 00 · case 02
A line without house digits gets delivery point 00.
Delivery point check digit: missing house number defaults to 00 · case 03
A line without house digits gets delivery point 00.
Delivery point check digit: missing house number defaults to 00 · case 04
A line without house digits gets delivery point 00.
Delivery point check digit: missing house number defaults to 00 · case 05
A line without house digits gets delivery point 00.
Delivery point check digit: delivery point is appended to five-digit codes · case 01
A code without plus-four still carries a delivery point.
Delivery point check digit: delivery point is appended to five-digit codes · case 02
A code without plus-four still carries a delivery point.
Delivery point check digit: delivery point is appended to five-digit codes · case 03
A code without plus-four still carries a delivery point.
Delivery point check digit: delivery point is appended to five-digit codes · case 04
A code without plus-four still carries a delivery point.
Delivery point check digit: delivery point is appended to five-digit codes · case 05
A code without plus-four still carries a delivery point.
Attention and care-of line extractor: words that start with a prefix are captured · case 01
"CARE OFFICE PARK" becomes care-of "FICE PARK".
Attention and care-of line extractor: words that start with a prefix are captured · case 02
"CARE OFFICE PARK" becomes care-of "FICE PARK".
Attention and care-of line extractor: words that start with a prefix are captured · case 03
"CARE OFFICE PARK" becomes care-of "FICE PARK".
Attention and care-of line extractor: words that start with a prefix are captured · case 04
"CARE OFFICE PARK" becomes care-of "FICE PARK".
Attention and care-of line extractor: words that start with a prefix are captured · case 05
"CARE OFFICE PARK" becomes care-of "FICE PARK".
Attention and care-of line extractor: a later attention line overwrites the first · case 01
"ATTN SHIPPING" replaces the named recipient and vanishes from the address lines.
Attention and care-of line extractor: a later attention line overwrites the first · case 02
"ATTN SHIPPING" replaces the named recipient and vanishes from the address lines.
Attention and care-of line extractor: a later attention line overwrites the first · case 03
"ATTN SHIPPING" replaces the named recipient and vanishes from the address lines.
Attention and care-of line extractor: a later attention line overwrites the first · case 04
"ATTN SHIPPING" replaces the named recipient and vanishes from the address lines.
Attention and care-of line extractor: a later attention line overwrites the first · case 05
"ATTN SHIPPING" replaces the named recipient and vanishes from the address lines.
Attention and care-of line extractor: the colon stays in front of the name · case 01
Attention is ": PAT EXAMPLE".
Attention and care-of line extractor: the colon stays in front of the name · case 02
Attention is ": PAT EXAMPLE".
Attention and care-of line extractor: the colon stays in front of the name · case 03
Attention is ": PAT EXAMPLE".
Attention and care-of line extractor: the colon stays in front of the name · case 04
Attention is ": PAT EXAMPLE".
Attention and care-of line extractor: the colon stays in front of the name · case 05
Attention is ": PAT EXAMPLE".
Attention and care-of line extractor: runs of spaces survive into values · case 01
Care-of reads "FAKECO LLC".
Attention and care-of line extractor: runs of spaces survive into values · case 02
Care-of reads "FAKECO LLC".
Attention and care-of line extractor: runs of spaces survive into values · case 03
Care-of reads "FAKECO LLC".
Attention and care-of line extractor: runs of spaces survive into values · case 04
Care-of reads "FAKECO LLC".
Attention and care-of line extractor: runs of spaces survive into values · case 05
Care-of reads "FAKECO LLC".
Attention and care-of line extractor: lowercase prefixes are not recognized · case 01
"attention: sam demo" stays an address line.
Attention and care-of line extractor: lowercase prefixes are not recognized · case 02
"attention: sam demo" stays an address line.
Attention and care-of line extractor: lowercase prefixes are not recognized · case 03
"attention: sam demo" stays an address line.
Attention and care-of line extractor: lowercase prefixes are not recognized · case 04
"attention: sam demo" stays an address line.
Attention and care-of line extractor: lowercase prefixes are not recognized · case 05
"attention: sam demo" stays an address line.
Attention and care-of line extractor: the spelled care-of prefix is missing · case 01
"CARE OF FAKECO" is left as an address line.
Attention and care-of line extractor: the spelled care-of prefix is missing · case 02
"CARE OF FAKECO" is left as an address line.
Attention and care-of line extractor: the spelled care-of prefix is missing · case 03
"CARE OF FAKECO" is left as an address line.
Attention and care-of line extractor: the spelled care-of prefix is missing · case 04
"CARE OF FAKECO" is left as an address line.
Attention and care-of line extractor: the spelled care-of prefix is missing · case 05
"CARE OF FAKECO" is left as an address line.
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 ↗