YAML Indentation Variants
The indentation styles that all parse identically and that formatters fight over: sequences flush with their key versus indented under it, two-space against four-space maps, and deliberately irregular but legal nesting. For testing formatters and idempotency.
# Indentation variants. All of these are valid YAML; linters and formatters disagree about which
# to enforce, and a rewriter that normalises them changes bytes without changing meaning — which
# matters when the file is under review or checksum.
sequence_flush_with_key:
- one
- two
sequence_indented_under_key:
- one
- two
map_two_space:
a: 1
b: 2
map_four_space:
a: 1
b: 2
irregular_but_legal:
deeply:
nested: value
sequence_of_maps_flush:
- name: build
needs: []
- name: test
needs:
- build
sequence_of_maps_indented:
- name: build
needs: []
- name: test
needs:
- build
Specifications
- Sequence Indent Styles
- 2
- Map Indent Widths
- 3
- Irregular But Legal Nesting
- 1
- Edge Case
- all variants are valid; formatters disagree about which to enforce
Testing contract
Expected to pass- Scenario
- Confirm that differently indented YAML loads to identical data before reformatting it
- Expected result
- sequence_flush_with_key and sequence_indented_under_key load to equal lists, and reformatting the file twice produces byte-identical output the second time
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 Indentation Variants” is a deterministic Novus Examples 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 · 640 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("indentation-variants.yaml") as f:
data = yaml.safe_load(f)
print(data)Related files
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- yamlYAML Bounded Anchor ReuseNested anchor reuse kept deliberately small: two anchors, six references, thirty-one expanded nodes. It is here to test alias resolution and expansion accounting on a safe input, and is explicitly not a billion-laughs expansion bomb.

- yamlYAML Directives and CommentsA two-document stream where each document declares its own %YAML directive and the second adds a %TAG handle used by a local tag. Comments appear in every position they are legal, and every one of them is lost by a non-round-tripping loader.

- yamlYAML Duplicate KeysDuplicate keys at three nesting levels, including a duplicated top-level sequence. The spec forbids them; most loaders keep the last silently, a few keep the first, and strict linters reject the document. The file publishes the last-wins answer.

- yamlYAML Explicit and Local TagsExplicit tags across the standard set — !!str, !!float, !!int, !!bool, !!null, !!binary, !!timestamp, !!omap, !!set — alongside two application-local ! tags. CI dialects use local tags in the wild, so a pipeline parser has to decide whether to reject, ignore, or resolve them.

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