.eslintrc.yml

env:
  es6: true
  node: true
extends:
  - standard
  - plugin:flowtype/recommended
  - plugin:import/recommended
parser: babel-eslint
parserOptions:
  ecmaFeatures:
    impliedStrict: true
  ecmaVersion: 2017
  sourceType: module
plugins:
  - flowtype
  - import
rules:
  # JavaScript
  comma-dangle: [warn, only-multiline]
  generator-star-spacing: [error, after]
  indent: [error, 2, {
    SwitchCase: 1,
    VariableDeclarator: 1,
    outerIIFEBody: 1,
    MemberExpression: 1,
    # Changed parameters from 1 to off.
    FunctionDeclaration: { parameters: off, body: 1 },
    # Changed parameters from 1 to off.
    FunctionExpression: { parameters: off, body: 1 },
    # Changed arguments from 1 to off.
    CallExpression: { arguments: off },
    ArrayExpression: 1,
    ObjectExpression: 1,
    ImportDeclaration: 1,
    flatTernaryExpressions: false,
    ignoreComments: false,
  }]
  linebreak-style: [error, unix]
  no-multi-spaces: [error, {
    ignoreEOLComments: true,
  }]
  no-multiple-empty-lines: [warn, {
    max: 2,
    maxEOF: 1,
    maxBOF: 1,
  }]
  # Replaced by flowtype/no-unused-expressions.
  no-unused-expressions: [off]
  no-var: [error]
  operator-linebreak: [error, before]
  padded-blocks: [off]
  yield-star-spacing: [error, after]

  # Flow
  flowtype/array-style-complex-type: [error, verbose]
  flowtype/array-style-simple-type: [error, verbose]
  flowtype/delimiter-dangle: [warn, only-multiline]
  flowtype/no-dupe-keys: [error]
  flowtype/no-flow-fix-me-comments: [warn]
  flowtype/no-primitive-constructor-types: [error]
  flowtype/no-types-missing-file-annotation: [error]
  flowtype/no-unused-expressions: [error, {
    allowShortCircuit: true,
    allowTernary: true,
    allowTaggedTemplates: true,
  }]
  flowtype/no-weak-types: [warn]
  flowtype/object-type-delimiter: [error, comma]
  flowtype/require-parameter-type: [error, {
    excludeArrowFunctions: true,
    excludeParameterMatch: "^_",
  }]
  flowtype/require-types-at-top: [warn, always]
  flowtype/require-valid-file-annotation: [warn, always, {
    annotationStyle: line,
  }]
  flowtype/semi: [error, never]
  flowtype/type-id-match: [error, "^([A-Z][a-z0-9]*)+$"]

  # ES6 modules
  import/no-commonjs: [error]
  import/no-amd: [error]
  import/first: [warn]
  import/exports-last: [warn]
  import/newline-after-import: [warn]

overrides:
  - files:
      - "*.test.js"
      - "scripts/*"
    rules:
      comma-spacing: [off]
      flowtype/require-parameter-type: [off]
      flowtype/require-valid-file-annotation: [off]
      import/no-commonjs: [off]
      no-multi-spaces: [off]
      standard/array-bracket-even-spacing: [off]