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
Default element namespaces are incorrectly applied to attributes · case 01
Default element namespaces are incorrectly applied to attributes.
Default element namespaces are incorrectly applied to attributes · case 02
Default element namespaces are incorrectly applied to attributes.
Default element namespaces are incorrectly applied to attributes · case 03
Default element namespaces are incorrectly applied to attributes.
Default element namespaces are incorrectly applied to attributes · case 04
Default element namespaces are incorrectly applied to attributes.
Default element namespaces are incorrectly applied to attributes · case 05
Default element namespaces are incorrectly applied to attributes.
Element matching relies on a source prefix spelling · case 01
Element matching relies on a source prefix spelling.
Element matching relies on a source prefix spelling · case 02
Element matching relies on a source prefix spelling.
Element matching relies on a source prefix spelling · case 03
Element matching relies on a source prefix spelling.
Element matching relies on a source prefix spelling · case 04
Element matching relies on a source prefix spelling.
Element matching relies on a source prefix spelling · case 05
Element matching relies on a source prefix spelling.
Markdown escaping modifies alphanumeric text · case 01
Markdown escaping modifies alphanumeric text.
Markdown escaping modifies alphanumeric text · case 02
Markdown escaping modifies alphanumeric text.
Markdown escaping modifies alphanumeric text · case 03
Markdown escaping modifies alphanumeric text.
Markdown escaping modifies alphanumeric text · case 04
Markdown escaping modifies alphanumeric text.
Markdown escaping modifies alphanumeric text · case 05
Markdown escaping modifies alphanumeric text.
A quoted-all dialect leaves ordinary fields bare · case 01
A quoted-all dialect leaves ordinary fields bare.
A quoted-all dialect leaves ordinary fields bare · case 02
A quoted-all dialect leaves ordinary fields bare.
A quoted-all dialect leaves ordinary fields bare · case 03
A quoted-all dialect leaves ordinary fields bare.
A quoted-all dialect leaves ordinary fields bare · case 04
A quoted-all dialect leaves ordinary fields bare.
A quoted-all dialect leaves ordinary fields bare · case 05
A quoted-all dialect leaves ordinary fields bare.
A backslash-escaped delimiter is treated as a field boundary · case 01
A backslash-escaped delimiter is treated as a field boundary.
A backslash-escaped delimiter is treated as a field boundary · case 02
A backslash-escaped delimiter is treated as a field boundary.
A backslash-escaped delimiter is treated as a field boundary · case 03
A backslash-escaped delimiter is treated as a field boundary.
A backslash-escaped delimiter is treated as a field boundary · case 04
A backslash-escaped delimiter is treated as a field boundary.
A backslash-escaped delimiter is treated as a field boundary · case 05
A backslash-escaped delimiter is treated as a field boundary.
An empty query field is confused with an absent field · case 01
An empty query field is confused with an absent field.
An empty query field is confused with an absent field · case 02
An empty query field is confused with an absent field.
An empty query field is confused with an absent field · case 03
An empty query field is confused with an absent field.
An empty query field is confused with an absent field · case 04
An empty query field is confused with an absent field.
An empty query field is confused with an absent field · case 05
An empty query field is confused with an absent field.
A base64 token contains MIME line wrapping · case 01
A base64 token contains MIME line wrapping.
A base64 token contains MIME line wrapping · case 02
A base64 token contains MIME line wrapping.
A base64 token contains MIME line wrapping · case 03
A base64 token contains MIME line wrapping.
A base64 token contains MIME line wrapping · case 04
A base64 token contains MIME line wrapping.
A base64 token contains MIME line wrapping · case 05
A base64 token contains MIME line wrapping.
Hex formatting places a separator between nybbles · case 01
Hex formatting places a separator between nybbles.
Hex formatting places a separator between nybbles · case 02
Hex formatting places a separator between nybbles.
Hex formatting places a separator between nybbles · case 03
Hex formatting places a separator between nybbles.
Hex formatting places a separator between nybbles · case 04
Hex formatting places a separator between nybbles.
Hex formatting places a separator between nybbles · case 05
Hex formatting places a separator between nybbles.
HTML escaping double-escapes the entities it just generated · case 01
HTML escaping double-escapes the entities it just generated.
HTML escaping double-escapes the entities it just generated · case 02
HTML escaping double-escapes the entities it just generated.
HTML escaping double-escapes the entities it just generated · case 03
HTML escaping double-escapes the entities it just generated.
HTML escaping double-escapes the entities it just generated · case 04
HTML escaping double-escapes the entities it just generated.
HTML escaping double-escapes the entities it just generated · case 05
HTML escaping double-escapes the entities it just generated.
A postfix parser reverses noncommutative operands · case 01
A postfix parser reverses noncommutative operands.
A postfix parser reverses noncommutative operands · case 02
A postfix parser reverses noncommutative operands.
A postfix parser reverses noncommutative operands · case 03
A postfix parser reverses noncommutative operands.
A postfix parser reverses noncommutative operands · case 04
A postfix parser reverses noncommutative operands.
A postfix parser reverses noncommutative operands · case 05
A postfix parser reverses noncommutative operands.
A prefix AST silently ignores an unconsumed token · case 01
A prefix AST silently ignores an unconsumed token.
A prefix AST silently ignores an unconsumed token · case 02
A prefix AST silently ignores an unconsumed token.
A prefix AST silently ignores an unconsumed token · case 03
A prefix AST silently ignores an unconsumed token.
A prefix AST silently ignores an unconsumed token · case 04
A prefix AST silently ignores an unconsumed token.
A prefix AST silently ignores an unconsumed token · case 05
A prefix AST silently ignores an unconsumed token.
A subtraction chain builds a right-associated tree · case 01
A subtraction chain builds a right-associated tree.
A subtraction chain builds a right-associated tree · case 02
A subtraction chain builds a right-associated tree.
A subtraction chain builds a right-associated tree · case 03
A subtraction chain builds a right-associated tree.
A subtraction chain builds a right-associated tree · case 04
A subtraction chain builds a right-associated tree.
A subtraction chain builds a right-associated tree · case 05
A subtraction chain builds a right-associated tree.
An exponentiation chain builds a left-associated tree · case 01
An exponentiation chain builds a left-associated tree.
An exponentiation chain builds a left-associated tree · case 02
An exponentiation chain builds a left-associated tree.
An exponentiation chain builds a left-associated tree · case 03
An exponentiation chain builds a left-associated tree.
An exponentiation chain builds a left-associated tree · case 04
An exponentiation chain builds a left-associated tree.
An exponentiation chain builds a left-associated tree · case 05
An exponentiation chain builds a left-associated tree.
A multiplication operator binds no tighter than addition · case 01
A multiplication operator binds no tighter than addition.
A multiplication operator binds no tighter than addition · case 02
A multiplication operator binds no tighter than addition.
A multiplication operator binds no tighter than addition · case 03
A multiplication operator binds no tighter than addition.
A multiplication operator binds no tighter than addition · case 04
A multiplication operator binds no tighter than addition.
A multiplication operator binds no tighter than addition · case 05
A multiplication operator binds no tighter than addition.
Front-coded strings ignore the previous decoded prefix · case 01
Front-coded strings ignore the previous decoded prefix.
Front-coded strings ignore the previous decoded prefix · case 02
Front-coded strings ignore the previous decoded prefix.
Front-coded strings ignore the previous decoded prefix · case 03
Front-coded strings ignore the previous decoded prefix.
Front-coded strings ignore the previous decoded prefix · case 04
Front-coded strings ignore the previous decoded prefix.
Front-coded strings ignore the previous decoded prefix · case 05
Front-coded strings ignore the previous decoded prefix.
COBS decoding inserts a zero after the final block · case 01
COBS decoding inserts a zero after the final block.
COBS decoding inserts a zero after the final block · case 02
COBS decoding inserts a zero after the final block.
COBS decoding inserts a zero after the final block · case 03
COBS decoding inserts a zero after the final block.
COBS decoding inserts a zero after the final block · case 04
COBS decoding inserts a zero after the final block.
COBS decoding inserts a zero after the final block · case 05
COBS decoding inserts a zero after the final block.
Reverse retains multiplicity · case 01
The operation returns a result or retained state that violates this contract: Reverse the complete list, retaining every occurrence.
Reverse retains multiplicity · case 02
The operation returns a result or retained state that violates this contract: Reverse the complete list, retaining every occurrence.
Reverse retains multiplicity · case 03
The operation returns a result or retained state that violates this contract: Reverse the complete list, retaining every occurrence.
Reverse retains multiplicity · case 04
The operation returns a result or retained state that violates this contract: Reverse the complete list, retaining every occurrence.
Reverse retains multiplicity · case 05
The operation returns a result or retained state that violates this contract: Reverse the complete list, retaining every occurrence.
Stable first occurrence uniqueness · case 01
The operation returns a result or retained state that violates this contract: Keep each value once in first-appearance order.
Stable first occurrence uniqueness · case 02
The operation returns a result or retained state that violates this contract: Keep each value once in first-appearance order.
Stable first occurrence uniqueness · case 03
The operation returns a result or retained state that violates this contract: Keep each value once in first-appearance order.
Stable first occurrence uniqueness · case 04
The operation returns a result or retained state that violates this contract: Keep each value once in first-appearance order.
Stable first occurrence uniqueness · case 05
The operation returns a result or retained state that violates this contract: Keep each value once in first-appearance order.
Stable last occurrence uniqueness · case 01
The operation returns a result or retained state that violates this contract: Keep only last occurrences, ordered by their original positions.
Stable last occurrence uniqueness · case 02
The operation returns a result or retained state that violates this contract: Keep only last occurrences, ordered by their original positions.
Stable last occurrence uniqueness · case 03
The operation returns a result or retained state that violates this contract: Keep only last occurrences, ordered by their original positions.
Stable last occurrence uniqueness · case 04
The operation returns a result or retained state that violates this contract: Keep only last occurrences, ordered by their original positions.
Stable last occurrence uniqueness · case 05
The operation returns a result or retained state that violates this contract: Keep only last occurrences, ordered by their original positions.
Adjacent run collapse · case 01
The operation returns a result or retained state that violates this contract: Collapse adjacent equal values only; separated repetitions remain.
Adjacent run collapse · case 02
The operation returns a result or retained state that violates this contract: Collapse adjacent equal values only; separated repetitions remain.
Adjacent run collapse · case 03
The operation returns a result or retained state that violates this contract: Collapse adjacent equal values only; separated repetitions remain.
Adjacent run collapse · case 04
The operation returns a result or retained state that violates this contract: Collapse adjacent equal values only; separated repetitions remain.
Adjacent run collapse · case 05
The operation returns a result or retained state that violates this contract: Collapse adjacent equal values only; separated repetitions remain.
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 ↗