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ProbeLabs23 findings · 123 requirements

The fastest JSON parser for Go — formally verified with ReqProof (real library, master).

All requirements
RequirementSYS-REQ-060SystemReview

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.

This requirement changed after its last recorded review, so approval is stale. Automated checks pass and 1/1 obligations are satisfied.
PriorityshallTypeguaranteeCategoryfunctionalComponentparserAssuranceEFindingsnone open

Specification

The requirement exactly as authored — its complete prose text and, where present, the formal FRETish sentence it compiles to.

Description

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.

FRETish formula
the parser shall always satisfy !raw_string_has_truncated_escape_sequence | returns_error_for_truncated_escape_sequence
View full formal model

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.

parsestringescapetruncation

Verification & provenance

How this requirement was checked: the review trail, edit history, and the machine-analysis status terms (each ⓘ explains what it means).

Assurance levelE
Formalizationvalid
Realizabilityrealizable
Vacuitychecked_ok
Strategyfretish

Review

Status
approved
Reviewer
Leonidbugaev
Reviewed
Apr 23, 2026, 00:00 UTC

History

Created
Apr 14, 2026, 18:00 UTC · Claude · AI agent
Modified
Jul 26, 2026, 14:54 UTC · Created via CLI

Change history

Every recorded revision of this requirement's source file — newest first, each with its commit message and the diff for that change.

Every recorded revision of this object's source — newest first, each with the commit message and its file-level diff.

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 catalogue
Discharged
If it were violatedCritical

ParseString 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.

Discharging evidence1/1 required witnessed
  • nominalrequiredpresent
    Covered 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).

FRETish formula

the parser shall always satisfy !raw_string_has_truncated_escape_sequence | returns_error_for_truncated_escape_sequence

Variables

NameTypeDirectionDescription
raw_string_has_truncated_escape_sequenceTrue 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_sequenceTrue when ParseString returns MalformedValueError for a truncated escape sequence.

Witnesses· 3 scenarios total

  • TestMCDC_SYS_REQ_060_Row1_TriggerFalse
    exercises 1 condition scenario
  • TestMCDC_SYS_REQ_060_Row2_InvariantViolation
    exercises 1 condition scenario
  • TestMCDC_SYS_REQ_060_Row3_TruncatedEscapeError
    exercises 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.

Covereda test exercises this rowExempteda reviewed mcdc:ignoreNo-actionfalse-result row satisfied by designUncoveredneeds a covering test
#raw_string_has_truncated_escape_sequencereturns_error_for_truncated_escape_sequenceResultProvesCovering test
1FFTraw_string_has_truncated_escape_sequence
2TFFraw_string_has_truncated_escape_sequence
3TTTreturns_error_for_truncated_escape_sequence

Its place

This requirement shown inside its trace neighbourhood — the parents it satisfies, the code and tests attached to it, and its findings.

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Trace evidence

The concrete artifacts linked to this requirement — implementing code, verifying tests, documents, and the findings raised against it.

Impact

Blast radius — if you change this requirement, what else may need re-checking, and what it in turn depends on.

If you change this

Requirements
0
Files
1
Tests
3
At-risk contracts
0

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

Discussions

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