CodeStyle

Code style for services

Requirements

• ESLint 10 is bundled; Node.js ^20.19.0 || ^22.13.0 || >=24.

• TypeScript 6 (peerDependencies.typescript: ^6.0) installed in the project, as typed linting uses it. typescript-eslint does not support TypeScript 7, which has no compiler API; to type-check with TypeScript 7, keep TypeScript 6 under the typescript name:

  {
  	"devDependencies": {
  		"@typescript/native": "npm:typescript@^7.0.2",
  		"typescript": "npm:@typescript/typescript6@^6.0.2"
  	}
  }

Prettier

Markdown tables in docs/**/*.md are printed compact (| a | b |) instead of padded to the column width, because padding wide tables in long documents more than doubles their size. Set the markdownTables option to aligned or compact in a project's prettier overrides to change it.

Rules

sos/changelog

Lints CHANGELOG.md files to enforce the Keep a Changelog format. It is enabled for **/CHANGELOG.md files using the custom sos/changelog language and is auto-fixable where possible (it intentionally does not fix anything where meaning is ambiguous).

It checks:

• Preamble – the file must start with the standard Keep a Changelog / Semantic Versioning header (auto-fixed).
• Versions – each released version heading must be [<semver>] - <date>, with a valid semver version and a valid date (or unknown). The [Unreleased] heading is recognized as a special version.
• Sections – section headings must be one of Added, Fixed, Changed, Removed, Deprecated, Security. Headings can't be indented.
• Entries – entries in released versions must start with - (auto-fixed for wrong prefixes where possible); entries under [Unreleased] must start with + instead. Optional tab indentation is allowed for nesting. Top-level entries must also start with one of the configured entry prefixes, e.g. (public)/(internal).
• Whitespace – flags irregular (double) whitespace, and requires a trailing empty line after the last entry in a section (auto-fixed).

Options

• allowedSections (string[]) – override the list of permitted section names. Defaults to ['Added', 'Fixed', 'Changed', 'Removed', 'Deprecated', 'Security'].
• entryPrefixes (string[]) – override the list of allowed entry prefixes. Defaults to ['(public)', '(internal)']. Pass [] to disable the check.

{
	files: ['**/CHANGELOG.md'],
	language: 'sos/changelog',
	plugins: {
		sos: eslintPluginSos,
	},
	rules: {
		'prettier/prettier': 'off',
		'sos/changelog': ['error', { allowedSections: ['Added', 'Fixed', 'Changed'] }],
	},
}

sos/changelog-fragment

Lints changelog/<feature>.md fragment files — the per-branch files a fragment workflow writes entries to instead of editing CHANGELOG.md directly, later spliced into a version by @signageos/changelog's appendSections. It is enabled for **/changelog/*.md files using the custom sos/changelog-fragment language and checks the same rules as sos/changelog, minus the ones that only apply to a whole CHANGELOG.md (preamble, version headings, version order):

• Sections – section headings must be one of Added, Fixed, Changed, Removed, Deprecated, Security. Headings can't be indented.
• Entries – entries must start with - (auto-fixed for wrong prefixes where possible) and one of the configured entry prefixes, e.g. (public)/(internal). Optional tab indentation is allowed for nesting.
• Whitespace – flags irregular (double) whitespace, and requires a trailing empty line after the last entry in a section (auto-fixed).

Options

• allowedSections (string[]) – override the list of permitted section names. Defaults to ['Added', 'Fixed', 'Changed', 'Removed', 'Deprecated', 'Security'].
• entryPrefixes (string[]) – override the list of allowed entry prefixes. Defaults to ['(public)', '(internal)']. Pass [] to disable the check.

{
	files: ['**/changelog/*.md'],
	language: 'sos/changelog-fragment',
	plugins: {
		sos: eslintPluginSos,
	},
	rules: {
		'prettier/prettier': 'off',
		'sos/changelog-fragment': 'error',
	},
}