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jsonparser
ProbeLabsviewing a historical runWhen ParseString receives a string literal containing a truncated escape sequence (e.g., a backslash at end of string, or a unicode escape like '\u00' with insufficient hex digits), the parser shall return MalformedValueError.
Specification
The requirement exactly as authored — its complete prose text and, where present, the formal FRETish sentence it compiles to.
When ParseString receives a string literal containing a truncated escape sequence (e.g., a backslash at end of string, or a unicode escape like '\u00' with insufficient hex digits), the parser shall return MalformedValueError.
the parser shall always satisfy !raw_string_has_truncated_escape_sequence | returns_error_for_truncated_escape_sequence
Rationale & tags
Why this requirement exists, and how it is categorised.
Rationale & tags
Why this requirement exists, and how it is categorised.
Truncated escape sequences exercise the unescapeToUTF8 and decodeUnicodeEscape boundary conditions where insufficient input length is checked.
Verification & provenance
How this requirement was checked: the review trail, edit history, and the machine-analysis status terms (each ⓘ explains what it means).
Review
- Status
- approved
- Reviewer
- Buger · lead_engineer
- Reviewed
- Aug 20, 2026, 13:11 UTC
History
- Created
- Apr 14, 2026, 18:00 UTC · Claude · AI agent
- Modified
- Aug 20, 2026, 13:11 UTC · Buger
Change history
Every recorded revision of this requirement's source file — newest first, each with its commit message and the diff for that change.
Review history
Human and AI-agent approvals of this requirement — the 'why was this approved' lineage, each with the reviewer's justification and the code it cites.
- Claude:spec Conformance · AI agentApprovedSpec conformanceAug 20, 2026 · last monthREVIEW-42
The formula requires a truncated escape sequence in ParseString to yield MalformedValueError, and the structure is sound: ParseString (parser.go:2148) returns MalformedValueError whenever Unescape errors, and decodeSingleUnicodeEscape is meant to reject short input before reading the four hex digits. However two tracked defects break this in the demo tree: KI-5 weakened the length guard at escape.go:88 from
len(in) < 6tolen(in) < 4, so a truncated\u00passes the guard and decodeSingleUnicodeEscape indexes in[4]/in[5] out of bounds, panicking instead of returning an error, and KI-9 widened the hex bound at escape.go:71 toc <= 71so byte 'G' decodes as 16. I confirmed the failure empirically:go test -run TestTruncatedEscapeSequencespanics with index-out-of-range at escape.go:93 via decodeSingleUnicodeEscape, exactly the KI-5 path. Both defects are honestly tracked as open KIs, so the requirement is approvable despite verification failing.Cited code (4)
Open known issues
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Obligations
What this requirement must witness to be considered satisfied — the required evidence, and the tests that discharge each one.
1 obligation · 1 discharged
Browse the catalogueParseString on a token like \u00 (truncated unicode escape) reads 4 hex digits past EOF in the hex-decode loop, panicking with index-out-of-range or producing a corrupt rune.
- nominalrequiredpresentCovered by 1 test
Formula evidence
The formal formula behind this requirement, the variables it is written over, and the tests that exercise it (each term is explained inline).
Formula evidence
The formal formula behind this requirement, the variables it is written over, and the tests that exercise it (each term is explained inline).
FRETish formula
the parser shall always satisfy !raw_string_has_truncated_escape_sequence | returns_error_for_truncated_escape_sequence
Variables
| Name | Type | Direction | Description |
|---|---|---|---|
| raw_string_has_truncated_escape_sequence | — | True when ParseString receives a string containing a truncated escape sequence such as a lone backslash or incomplete unicode escape like '\u00'. | |
| returns_error_for_truncated_escape_sequence | — | True when ParseString returns MalformedValueError for a truncated escape sequence. |
Witnesses· 3 scenarios total
- TestMCDC_SYS_REQ_060_Row1_TriggerFalseexercises 1 condition scenario
- TestMCDC_SYS_REQ_060_Row2_InvariantViolationexercises 1 condition scenario
- TestMCDC_SYS_REQ_060_Row3_TruncatedEscapeErrorexercises 1 condition scenario
MC/DC truth table· 3 rows
Each row assigns the formula's conditions (T/F) and shows the Result— the formula's value for that input row, not a test pass/fail. A row proves a condition when flipping only that condition flips the outcome. The test that covers each row is linked.
mcdc:ignoreNo-actionfalse-result row satisfied by designUncoveredneeds a covering test| # | raw_string_has_truncated_escape_sequence | returns_error_for_truncated_escape_sequence | Result | Proves | Covering test |
|---|---|---|---|---|---|
| 1 | F | F | T | raw_string_has_truncated_escape_sequence | |
| 2 | T | F | F | raw_string_has_truncated_escape_sequence | |
| 3 | T | T | T | returns_error_for_truncated_escape_sequence |
Its place
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Trace evidence
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Impact
Blast radius — authored trace links only (automatically derived links come from the audit index and aren't shown here).
Impact
Blast radius — authored trace links only (automatically derived links come from the audit index and aren't shown here).
If you change this
Files to re-check (1)
- parser.goparser.go
Tests to re-run (3)
- deep_spec_test.godeep_spec_test.go
- mcdc_spec_witnesses_test.gomcdc_spec_witnesses_test.go
- obligation_evidence_test.goobligation_evidence_test.go
What this rests on
Parent requirements (1)
Discussions
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