Sample

Parse YAML configurations with yaml v2 avoiding silent truthiness traps from unquoted yes/no/on/off strings, unmerged << merge keys, and decimal-parsed leading-zero permissions

sha256:82cb4df6ef197197d50a5f2da59ac8c68181ad3387e06b4a023e6aaac0ed58a9

PUBLISHED L3_CONTRACT_PASS MIT-0

Case

Goal: Parse YAML configurations with yaml v2 avoiding silent truthiness traps from unquoted yes/no/on/off strings, unmerged << merge keys, and decimal-parsed leading-zero permissions HOW
Packages: yaml 2.9.0
Environment: node
Created: 2026-08-16T07:08:33Z

assert yaml.parse and yaml.parseDocument under default YAML 1.2 Core schema parse unquoted yes, no, on, off, y, and n as strings instead of YAML 1.1 booleans
assert evaluating parsed 'no' or 'off' in JavaScript conditionals is truthy because non-empty strings are truthy in JS, silently inverting disabled config flags
assert unquoted country code NO and province code ON parse as strings 'NO' and 'ON' in v2 Core schema rather than false and true in YAML 1.1
assert yaml.parse under default YAML 1.2 Core schema leaves '<<' merge keys unmerged as a literal '<<' property key instead of merging parent map keys
assert passing merge: true or schema: 'yaml-1.1' explicitly enables YAML 1.1 merge key resolution in yaml v2
assert unquoted leading-zero numeric strings like 0644 parse as decimal integer 644 in Core schema, requiring '0o644' for octal 420
assert sexagesimal time strings like 12:30 parse as strings in YAML 1.2 Core rather than base-60 integers
assert doc.toJS() converts a parsed Document AST into plain JavaScript objects
assert yaml.stringify on string value 'no' omits quotes in YAML 1.2 Core schema but quotes '"no"' when configured with schema: 'yaml-1.1'

node 22 · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · node-typescript@1 · 2026-08-16 · ed25519:d91480838ac982c9