add eslint (#350)

.eslintignore

@@ -0,0 +1,9 @@
+lib/
+es/
+es6/
+*.d.ts
+src/**/*.js
+test/**/*.js
+.eslintrc.js
+jest.config.js
+coverage

.eslintrc.js

@@ -0,0 +1,123 @@
+module.exports = {
+  root: true,
+  parser: '@typescript-eslint/parser',
+  parserOptions: {
+    project: './tsconfig.json',
+    sourceType: 'module',
+    warnOnUnsupportedTypeScriptVersion: false,
+  },
+  extends: [
+    'airbnb-typescript/base',
+    'plugin:@typescript-eslint/recommended',
+  ],
+  env: {
+    node: true,
+  },
+  rules: {
+    'arrow-parens': ['error', 'as-needed', {
+      requireForBlockBody: false,
+    }],
+    'class-methods-use-this': 'off',
+    'constructor-super': 'error',
+    'handle-callback-err': 'error',
+    'no-await-in-loop': 'off',
+    'no-class-assign': 'error',
+    'no-continue': 'off',
+    'import/no-cycle': 'off',
+    'no-mixed-operators': ['error', {
+      allowSamePrecedence: true,
+    }],
+    'no-mixed-requires': 'error',
+    'no-new-require': 'error',
+    'no-path-concat': 'error',
+    'no-restricted-syntax': ['error',
+      'ForInStatement',
+      'LabeledStatement',
+      'WithStatement',
+    ],
+    'no-this-before-super': 'error',
+    'no-underscore-dangle': 'off',
+    'prefer-destructuring': ['error', {
+      'VariableDeclarator': {
+        array: false,
+        object: true,
+      },
+      'AssignmentExpression': {
+        array: false,
+        object: true,
+      }
+    }, {
+        enforceForRenamedProperties: false,
+      }],
+    'strict': ['error', 'global'],
+    'template-curly-spacing': ['error', 'always'],
+
+    'import/named': 'error',
+    'import/prefer-default-export': 'off',
+
+    '@typescript-eslint/array-type': ['error', {
+      default: 'generic',
+    }],
+    '@typescript-eslint/await-thenable': 'error',
+    '@typescript-eslint/explicit-function-return-type': ['error', {
+      allowExpressions: true,
+    }],
+    '@typescript-eslint/explicit-member-accessibility': ['error', {
+      'overrides': {
+        constructors: 'no-public',
+      }
+    }],
+    '@typescript-eslint/explicit-module-boundary-types': ['error', {
+      allowArgumentsExplicitlyTypedAsAny: true,
+    }],
+    '@typescript-eslint/indent': ['error', 4, {
+      SwitchCase: 1,
+      VariableDeclarator: 1,
+      outerIIFEBody: 1,
+      MemberExpression: 0,
+      FunctionDeclaration: {
+        parameters: 1,
+        body: 1,
+      },
+      FunctionExpression: {
+        parameters: 1,
+        body: 1,
+      },
+      CallExpression: {
+        arguments: 1,
+      },
+      ArrayExpression: 1,
+      ObjectExpression: 1,
+      ImportDeclaration: 1,
+      flatTernaryExpressions: false,
+      ignoredNodes: [
+        'JSXExpressionContainer > ConditionalExpression'
+      ],
+      ignoreComments: false,
+    }],
+    '@typescript-eslint/lines-between-class-members': ['error', 'always', {
+      exceptAfterSingleLine: true,
+    }],
+    '@typescript-eslint/naming-convention': [
+      "error",
+      {
+        selector: ['enum'],
+        format: ['UPPER_CASE'],
+      }
+    ],
+    '@typescript-eslint/no-explicit-any': 'off',
+    '@typescript-eslint/no-parameter-properties': 'off',
+    '@typescript-eslint/no-this-alias': 'error',
+    '@typescript-eslint/no-unnecessary-type-assertion': 'error',
+    '@typescript-eslint/no-unused-vars': ['error', {
+      vars: 'all',
+      args: 'after-used',
+      ignoreRestSiblings: true,
+    }],
+    '@typescript-eslint/no-use-before-define': ['error', 'nofunc'],
+    '@typescript-eslint/object-curly-spacing': ['error', 'never'],
+    '@typescript-eslint/prefer-function-type': 'error',
+    '@typescript-eslint/restrict-plus-operands': 'error',
+    '@typescript-eslint/unbound-method': 'error',
+  },
+};