yaml1 KB

YAML Implicit Typing Traps

Twenty-two unquoted values whose type depends entirely on the resolver. The worst is the leading zero: 0755 is 493 under YAML 1.1 and 755 under YAML 1.2, so both resolvers return a number and they return different ones. Also covers base-60 times, a version that loses its trailing zero, an integer past IEEE-754 precision, dates, and .inf / .nan.

Config parsing Encoding detection Editor testing

Preview, first 35 linesyaml

# Implicit typing. Nothing here is quoted, so every value is whatever the resolver decides it
# is — and the resolvers disagree. Each key names the trap it carries.
version_trailing_zero: 1.10
version_quoted: "1.10"

sexagesimal_time: 22:22
sexagesimal_duration: 1:30:00
time_quoted: "22:22"

# A leading zero is the nastiest of these, because BOTH resolvers return a number and they
# return DIFFERENT numbers: YAML 1.1 reads 0755 as octal (493), YAML 1.2's core schema reads
# it as plain decimal (755). Neither gives you back the text you wrote.
octal_yaml_1_1: 0755
octal_yaml_1_2: 0o755
leading_zero_identifier: 012345
# 9 is not an octal digit, so YAML 1.1 leaves this a string while YAML 1.2 makes it 900.
build_number_leading_zero: 0900
hexadecimal: 0x1F
binary_yaml_1_1: 0b1011

big_integer: 9007199254740993
float_precision: 0.1
exponent: 1e3
plus_signed: +42

date_only: 2026-01-15
date_time: 2026-01-15T09:30:00Z
date_quoted: "2026-01-15"

infinity: .inf
negative_infinity: -.inf
not_a_number: .nan

version_string_looks_numeric: 2.0

Specifications

Traps: 22
Sexagesimal Values: 2
Leading Zero Forms: 4
Precision Loss Value: 9007199254740992
Version Trailing Zero Loss: 1.10 -> 1.1
Leading Zero Disagreement: 0755 is 493 under YAML 1.1 and 755 under YAML 1.2 core

Testing contract

Expected to recover

Scenario: Round-trip unquoted YAML scalars whose type the resolver infers
Expected result: version_trailing_zero loads as the float 1.1 and dumps as "1.1", losing the original text, and octal_yaml_1_1 loads as 493 or 755 depending on the resolver version rather than staying "0755"

What is a .yaml file?

YAML (YAML Ain't Markup Language) is a human-readable data-serialization format using indentation, key-value pairs, and lists, and is a superset of JSON. It supports comments, anchors, and multiple documents per file, favoring readability for configuration. Its indentation sensitivity makes it error-prone to hand-edit.

How to use this file

Use an example YAML file to test config parsers, indentation and anchor handling, multi-document streams, and safe-loading to avoid arbitrary object construction.

How to use this file for testing

“YAML Implicit Typing Traps” is a deterministic Testaroo fixture for Config parsing, Encoding detection, Editor testing. TOML and INI configuration files with nested sections and typed values, for testing config parsers and loaders.

Documented properties for this file: YAML · 1,048 bytes. Compare results against paired or grouped companions on this page when present (clean↔damaged, searchable↔scanned, or format twins) so scores stay reproducible across runs.

Download the file once, keep the path stable in CI or local scripts, and treat the spec table as the contract: dimensions, seeds, field lists, and roles are intentional. Corrupt or invalid samples are labelled as such, expect parsers to fail loudly rather than silently accept them.

Pipeline and infrastructure fixtures are inert configuration: steps reference fictional images and scripts, and nothing here executes. Run your linter, schema validator, migrator, or policy engine against them, and expect the deprecated-syntax and intentionally invalid variants to be rejected.

Point your config loader at the file and assert it reads the documented sections and typed values, including any deliberately-tricky nesting or comments.

Code examples

import yaml  # pip install pyyaml

with open("implicit-typing.yaml") as f:
    data = yaml.safe_load(f)
print(data)

Generated by generation/pipelines.py. Free for any use, no attribution required, license.