README.md

eslint-plugin-flowtype

Flow type linting rules for ESLint.

{"gitdown": "contents"}

Installation

1. Install ESLint.
2. Install babel-eslint parser (ESLint parser does not support type annotations).
3. Install eslint-plugin-flowtype plugin.

npm install eslint --save-dev
npm install babel-eslint --save-dev
npm install eslint-plugin-flowtype --save-dev

# Or all at once:
npm install eslint babel-eslint eslint-plugin-flowtype --save-dev

Configuration

1. Set parser property to babel-eslint.
2. Add plugins section and specify eslint-plugin-flowtype as a plugin.
3. Enable rules.

{
  "parser": "babel-eslint",
  "plugins": [
    "flowtype"
  ],
  "rules": {
    "flowtype/boolean-style": [
      2,
      "boolean"
    ],
    "flowtype/define-flow-type": 1,
    "flowtype/delimiter-dangle": [
      2,
      "never"
    ],
    "flowtype/generic-spacing": [
      2,
      "never"
    ],
    "flowtype/interface-id-match": [
      2,
      "^([A-Z][a-z0-9]+)+Type$"
    ],
    "flowtype/no-mixed": 2,
    "flowtype/no-primitive-constructor-types": 2,
    "flowtype/no-types-missing-file-annotation": 2,
    "flowtype/no-weak-types": 2,
    "flowtype/object-type-delimiter": [
      2,
      "comma"
    ],
    "flowtype/require-parameter-type": 2,
    "flowtype/require-readonly-react-props": 0,
    "flowtype/require-return-type": [
      2,
      "always",
      {
        "annotateUndefined": "never"
      }
    ],
    "flowtype/require-valid-file-annotation": 2,
    "flowtype/semi": [
      2,
      "always"
    ],
    "flowtype/space-after-type-colon": [
      2,
      "always"
    ],
    "flowtype/space-before-generic-bracket": [
      2,
      "never"
    ],
    "flowtype/space-before-type-colon": [
      2,
      "never"
    ],
    "flowtype/type-id-match": [
      2,
      "^([A-Z][a-z0-9]+)+Type$"
    ],
    "flowtype/union-intersection-spacing": [
      2,
      "always"
    ],
    "flowtype/use-flow-type": 1,
    "flowtype/valid-syntax": 1
  },
  "settings": {
    "flowtype": {
      "onlyFilesWithFlowAnnotation": false
    }
  }
}

Shareable configurations

Recommended

This plugin exports a recommended configuration that enforces Flow type good practices.

To enable this configuration use the extends property in your .eslintrc config file:

{
  "extends": [
    "plugin:flowtype/recommended"
  ],
  "plugins": [
    "flowtype"
  ]
}

See ESLint documentation for more information about extending configuration files.

Community maintained configurations

The following are third-party submitted/ maintained configurations of eslint-plugin-flowtype:

• https://github.com/wemake-services/eslint-config-flowtype-essential

Settings

onlyFilesWithFlowAnnotation

When true, only checks files with a @flow annotation in the first comment.

{
  "settings": {
    "flowtype": {
      "onlyFilesWithFlowAnnotation": true
    }
  }
}

Rules

{"gitdown": "include", "file": "./rules/array-style-complex-type.md"} {"gitdown": "include", "file": "./rules/array-style-simple-type.md"} {"gitdown": "include", "file": "./rules/arrow-parens.md"} {"gitdown": "include", "file": "./rules/boolean-style.md"} {"gitdown": "include", "file": "./rules/define-flow-type.md"} {"gitdown": "include", "file": "./rules/delimiter-dangle.md"} {"gitdown": "include", "file": "./rules/enforce-line-break.md"} {"gitdown": "include", "file": "./rules/generic-spacing.md"} {"gitdown": "include", "file": "./rules/interface-id-match.md"} {"gitdown": "include", "file": "./rules/newline-after-flow-annotation.md"} {"gitdown": "include", "file": "./rules/no-dupe-keys.md"} {"gitdown": "include", "file": "./rules/no-duplicate-type-union-intersection-members.md"} {"gitdown": "include", "file": "./rules/no-existential-type.md"} {"gitdown": "include", "file": "./rules/no-flow-fix-me-comments.md"} {"gitdown": "include", "file": "./rules/no-internal-flow-type.md"} {"gitdown": "include", "file": "./rules/no-mixed.md"} {"gitdown": "include", "file": "./rules/no-mutable-array.md"} {"gitdown": "include", "file": "./rules/no-primitive-constructor-types.md"} {"gitdown": "include", "file": "./rules/no-types-missing-file-annotation.md"} {"gitdown": "include", "file": "./rules/no-unused-expressions.md"} {"gitdown": "include", "file": "./rules/no-weak-types.md"} {"gitdown": "include", "file": "./rules/object-type-curly-spacing.md"} {"gitdown": "include", "file": "./rules/object-type-delimiter.md"} {"gitdown": "include", "file": "./rules/quotes.md"} {"gitdown": "include", "file": "./rules/require-compound-type-alias.md"} {"gitdown": "include", "file": "./rules/require-exact-type.md"} {"gitdown": "include", "file": "./rules/require-indexer-name.md"} {"gitdown": "include", "file": "./rules/require-inexact-type.md"} {"gitdown": "include", "file": "./rules/require-parameter-type.md"} {"gitdown": "include", "file": "./rules/require-readonly-react-props.md"} {"gitdown": "include", "file": "./rules/require-return-type.md"} {"gitdown": "include", "file": "./rules/require-types-at-top.md"} {"gitdown": "include", "file": "./rules/require-valid-file-annotation.md"} {"gitdown": "include", "file": "./rules/require-variable-type.md"} {"gitdown": "include", "file": "./rules/semi.md"} {"gitdown": "include", "file": "./rules/sort-keys.md"} {"gitdown": "include", "file": "./rules/sort-type-union-intersection-members.md"} {"gitdown": "include", "file": "./rules/space-after-type-colon.md"} {"gitdown": "include", "file": "./rules/space-before-generic-bracket.md"} {"gitdown": "include", "file": "./rules/space-before-type-colon.md"} {"gitdown": "include", "file": "./rules/spread-exact-type.md"} {"gitdown": "include", "file": "./rules/type-id-match.md"} {"gitdown": "include", "file": "./rules/type-import-style.md"} {"gitdown": "include", "file": "./rules/union-intersection-spacing.md"} {"gitdown": "include", "file": "./rules/use-flow-type.md"} {"gitdown": "include", "file": "./rules/use-read-only-spread.md"} {"gitdown": "include", "file": "./rules/valid-syntax.md"}