Introduction

eslint-plugin-toml is ESLint plugin provides linting rules for TOML.

:name_badge: Features

This ESLint plugin provides linting rules for TOML.

• You can use ESLint to lint TOML.
• You can find out the problem with your TOML files.
• You can apply consistent code styles to your TOML files.
• Supports Vue SFC custom blocks such as <custom-block lang="toml">.
  Requirements vue-eslint-parser v7.3.0 and above.
• Supports ESLint directives. e.g. # eslint-disable-next-line
• You can check your code in real-time using the ESLint editor integrations.

You can check on the Online DEMO.

:book: Documentation

See documents.

:cd: Installation

npm install --save-dev eslint eslint-plugin-toml

Requirements

• ESLint v9.38.0 and above
• Node.js v20.19.x, v22.13.x, v24.x and above

:book: Usage

Configuration

Use eslint.config.js file to configure rules. See also: https://eslint.org/docs/latest/use/configure/configuration-files.

Example eslint.config.js:

import eslintPluginToml from 'eslint-plugin-toml';
export default [
  // add more generic rule sets here, such as:
  // js.configs.recommended,
  ...eslintPluginToml.configs.recommended,
  {
    rules: {
      // override/add rules settings here, such as:
    // 'toml/rule-name': 'error'
    }
  }
];

This plugin provides configs:

• *.configs.base ... Configuration to enable correct TOML parsing.
• *.configs.recommended ... Above, plus rules to prevent errors or unintended behavior.
• *.configs.standard ... Above, plus rules to enforce the common stylistic conventions.
• *.configs.all ... Configuration to enable correct TOML parsing and all non-deprecated rules. This config is not recommended for production use because it may change with every minor release. Use at your own risk.

For backward compatibility, you can also use the flat/* namespace:

• *.configs['flat/all']
• *.configs['flat/base']
• *.configs['flat/recommended']
• *.configs['flat/standard']

See the rule list to get the rules that this plugin provides.

Languages

This plugin provides the following language identifiers for use in ESLint configurations:

• toml/toml ... TOML files

For example, to apply settings specifically to TOML files, you can use the language field in your ESLint configuration:

import eslintPluginToml from 'eslint-plugin-toml';
export default [
  {
    files: ["*.toml", "**/*.toml"],
    plugins: {
      toml: eslintPluginToml,
    },
    language: "toml/toml",
  }
]

The configuration above is included in the shareable configs provided by this plugin, so using configs is generally recommended.

See also https://eslint.org/docs/latest/use/configure/plugins#specify-a-language

:computer: Editor Integrations

Visual Studio Code

Use the dbaeumer.vscode-eslint extension that Microsoft provides officially.

You have to configure the eslint.validate option of the extension to check .toml files, because the extension targets only *.js or *.jsx files by default.

Example .vscode/settings.json:

{
    "eslint.validate": [
        "javascript",
        "javascriptreact",
        "toml"
    ]
}

:white_check_mark: Rules

The --fix option on the command line automatically fixes problems reported by rules which have a wrench :wrench: below.
The rules with the following star :star: are included in the configs.

TOML Rules

Rule ID	Description	Fixable	RECOMMENDED	STANDARD
toml/indent	enforce consistent indentation	:wrench:		:star:
toml/keys-order	disallow defining pair keys out-of-order	:wrench:		:star:
toml/no-mixed-type-in-array	disallow mixed data types in array
toml/no-non-decimal-integer	disallow hexadecimal, octal and binary integer	:wrench:
toml/no-space-dots	disallow spacing around infix operators	:wrench:		:star:
toml/no-unreadable-number-separator	disallow number separators that to not enhance readability.		:star:	:star:
toml/padding-line-between-pairs	require or disallow padding lines between pairs	:wrench:		:star:
toml/padding-line-between-tables	require or disallow padding lines between tables	:wrench:		:star:
toml/precision-of-fractional-seconds	disallow precision of fractional seconds greater than the specified value.		:star:	:star:
toml/precision-of-integer	disallow precision of integer greater than the specified value.		:star:	:star:
toml/quoted-keys	require or disallow quotes around keys	:wrench:		:star:
toml/tables-order	disallow defining tables out-of-order	:wrench:		:star:
toml/vue-custom-block/no-parsing-error	disallow parsing errors in Vue custom blocks		:star:	:star:

Extension Rules

Rule ID	Description	Fixable	RECOMMENDED	STANDARD
toml/array-bracket-newline	enforce linebreaks after opening and before closing array brackets	:wrench:		:star:
toml/array-bracket-spacing	enforce consistent spacing inside array brackets	:wrench:		:star:
toml/array-element-newline	enforce line breaks between array elements	:wrench:		:star:
toml/comma-style	enforce consistent comma style in array	:wrench:		:star:
toml/inline-table-curly-newline	enforce linebreaks after opening and before closing braces	:wrench:		:star:
toml/inline-table-curly-spacing	enforce consistent spacing inside braces	:wrench:		:star:
toml/inline-table-key-value-newline	enforce placing inline table key-value pairs on separate lines	:wrench:		:star:
toml/key-spacing	enforce consistent spacing between keys and values in key/value pairs	:wrench:		:star:
toml/spaced-comment	enforce consistent spacing after the # in a comment	:wrench:		:star:
toml/table-bracket-spacing	enforce consistent spacing inside table brackets	:wrench:		:star:

Deprecated

• :warning: We're going to remove deprecated rules in the next major release. Please migrate to successor/new rules.
• :innocent: We don't fix bugs which are in deprecated rules since we don't have enough resources.

Rule ID	Replaced by
toml/space-eq-sign	toml/key-spacing

:beers: Contributing

Welcome contributing!

Please use GitHub's Issues/PRs.

Development Tools

• npm test runs tests and measures coverage.
• npm run update runs in order to update readme and recommended configuration.

Working With Rules

This plugin uses toml-eslint-parser for the parser. Check here to find out about AST.

:couple: Related Packages

• eslint-plugin-jsonc ... ESLint plugin for JSON, JSON with comments (JSONC) and JSON5.
• eslint-plugin-yml ... ESLint plugin for YAML.
• eslint-plugin-json-schema-validator ... ESLint plugin that validates data using JSON Schema Validator.
• jsonc-eslint-parser ... JSON, JSONC and JSON5 parser for use with ESLint plugins.
• yaml-eslint-parser ... YAML parser for use with ESLint plugins.
• toml-eslint-parser ... TOML parser for use with ESLint plugins.

:lock: License

See the LICENSE file for license rights and limitations (MIT).