eslint-plugin-toml/README.md

This ESLint plugin provides linting rules for TOML.

# Introduction

[eslint-plugin-toml](https://www.npmjs.com/package/eslint-plugin-toml) is ESLint plugin provides linting rules for [TOML].

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## :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](https://vue-loader.vuejs.org/spec.html) 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](https://ota-meshi.github.io/eslint-plugin-toml/playground/).

<!--DOCS_IGNORE_START-->

## :book: Documentation

See [documents](https://ota-meshi.github.io/eslint-plugin-toml/).

## :cd: Installation

```bash
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

<!--DOCS_IGNORE_END-->

## :book: Usage

<!--USAGE_SECTION_START-->
<!--USAGE_GUIDE_START-->

### Configuration

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

Example **eslint.config.js**:

```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](https://ota-meshi.github.io/eslint-plugin-toml/rules/) 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:

```js
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](https://marketplace.visualstudio.com/items?itemName=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**:

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

<!--USAGE_GUIDE_END-->
<!--USAGE_SECTION_END-->

## :white_check_mark: Rules

<!--RULES_SECTION_START-->

The `--fix` option on the [command line](https://eslint.org/docs/user-guide/command-line-interface#fixing-problems) automatically fixes problems reported by rules which have a wrench :wrench: below.  
The rules with the following star :star: are included in the configs.

<!--RULES_TABLE_START-->

### TOML Rules

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

### Extension Rules

| Rule ID | Description | Fixable | RECOMMENDED | STANDARD |
|:--------|:------------|:-------:|:-----------:|:--------:|
| [toml/array-bracket-newline](https://ota-meshi.github.io/eslint-plugin-toml/rules/array-bracket-newline.html) | enforce linebreaks after opening and before closing array brackets | :wrench: |  | :star: |
| [toml/array-bracket-spacing](https://ota-meshi.github.io/eslint-plugin-toml/rules/array-bracket-spacing.html) | enforce consistent spacing inside array brackets | :wrench: |  | :star: |
| [toml/array-element-newline](https://ota-meshi.github.io/eslint-plugin-toml/rules/array-element-newline.html) | enforce line breaks between array elements | :wrench: |  | :star: |
| [toml/comma-style](https://ota-meshi.github.io/eslint-plugin-toml/rules/comma-style.html) | enforce consistent comma style in array | :wrench: |  | :star: |
| [toml/inline-table-curly-newline](https://ota-meshi.github.io/eslint-plugin-toml/rules/inline-table-curly-newline.html) | enforce linebreaks after opening and before closing braces | :wrench: |  | :star: |
| [toml/inline-table-curly-spacing](https://ota-meshi.github.io/eslint-plugin-toml/rules/inline-table-curly-spacing.html) | enforce consistent spacing inside braces | :wrench: |  | :star: |
| [toml/inline-table-key-value-newline](https://ota-meshi.github.io/eslint-plugin-toml/rules/inline-table-key-value-newline.html) | enforce placing inline table key-value pairs on separate lines | :wrench: |  | :star: |
| [toml/key-spacing](https://ota-meshi.github.io/eslint-plugin-toml/rules/key-spacing.html) | enforce consistent spacing between keys and values in key/value pairs | :wrench: |  | :star: |
| [toml/spaced-comment](https://ota-meshi.github.io/eslint-plugin-toml/rules/spaced-comment.html) | enforce consistent spacing after the `#` in a comment | :wrench: |  | :star: |
| [toml/table-bracket-spacing](https://ota-meshi.github.io/eslint-plugin-toml/rules/table-bracket-spacing.html) | 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](https://ota-meshi.github.io/eslint-plugin-toml/rules/space-eq-sign.html) | [toml/key-spacing](https://ota-meshi.github.io/eslint-plugin-toml/rules/key-spacing.html.md) |

<!--RULES_TABLE_END-->
<!--RULES_SECTION_END-->

<!--DOCS_IGNORE_START-->

## :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](https://github.com/ota-meshi/toml-eslint-parser) for the parser. Check [here](https://ota-meshi.github.io/toml-eslint-parser/) to find out about AST.

<!--DOCS_IGNORE_END-->

## :couple: Related Packages

- [eslint-plugin-jsonc](https://github.com/ota-meshi/eslint-plugin-jsonc) ... ESLint plugin for JSON, JSON with comments (JSONC) and JSON5.
- [eslint-plugin-yml](https://github.com/ota-meshi/eslint-plugin-yml) ... ESLint plugin for YAML.
- [eslint-plugin-json-schema-validator](https://github.com/ota-meshi/eslint-plugin-json-schema-validator) ... ESLint plugin that validates data using JSON Schema Validator.
- [jsonc-eslint-parser](https://github.com/ota-meshi/jsonc-eslint-parser) ... JSON, JSONC and JSON5 parser for use with ESLint plugins.
- [yaml-eslint-parser](https://github.com/ota-meshi/yaml-eslint-parser) ... YAML parser for use with ESLint plugins.
- [toml-eslint-parser](https://github.com/ota-meshi/toml-eslint-parser) ... TOML parser for use with ESLint plugins.

## :lock: License

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

[TOML]: https://toml.io/