Merge pull request #12 from vend/v5

Update dependencies, revise lint rules

.eslintrc.js

@@ -0,0 +1,342 @@
+const restrictedGlobals = require('confusing-browser-globals')
+const prettierConfig = require('./prettier.config')
+
+module.exports = {
+  env: {
+    browser: true,
+  },
+  plugins: ['@typescript-eslint', 'jsx-a11y', 'prettier', 'react-hooks'],
+  settings: {
+    react: {
+      version: 'detect',
+    },
+  },
+  extends: [
+    'standard',
+    'standard-react',
+    // These should go last since they disable all formatting-related lints.
+    'plugin:prettier/recommended',
+    'prettier/react',
+    'prettier/standard',
+  ],
+  rules: {
+    // Prefer foo.bar over foo['bar'].
+    'dot-notation': 'error',
+
+    // Disallow use of the console object, such as console.log.
+    'no-console': 'error',
+
+    // Disallow empty conditional and loop bodies.
+    'no-empty': 'error',
+
+    // Don't allow Object prototype built-ins.
+    // Standard turns this on but it doesn't seem very useful.
+    'no-prototype-builtins': 'off',
+
+    // Disallow browser globals with generic names like 'event' and 'name'.
+    'no-restricted-globals': ['error'].concat(restrictedGlobals),
+
+    // Disabled so we don't have to change chai assertions.
+    // See: https://github.com/standard/standard/issues/690
+    'no-unused-expressions': 'off',
+
+    // Don't allow unused labels.
+    'no-unused-labels': 'off',
+
+    // Disallow the 'var' keyword.
+    'no-var': 'error',
+
+    // Prefer ES6 shorthand notation in object literals.
+    'object-shorthand': 'error',
+
+    // Make variables const when possible.
+    'prefer-const': 'error',
+
+    // Require the radix argument to parseInt to avoid unintentionally allowing hex or octal.
+    radix: 'error',
+
+    // Naming conventions. The TypeScript rule is much more complete and configurable than ESLint's.
+    camelcase: 'off',
+    '@typescript-eslint/naming-convention': [
+      'error',
+      {
+        selector: 'default',
+        format: ['camelCase'],
+        leadingUnderscore: 'allow',
+        trailingUnderscore: 'allow',
+      },
+      {
+        selector: 'variable',
+        // Allow PascalCase for React components, UPPER_CASE for constants.
+        format: ['camelCase', 'PascalCase', 'UPPER_CASE'],
+        leadingUnderscore: 'allow',
+        trailingUnderscore: 'allow',
+      },
+      {
+        selector: 'function',
+        // Allow PascalCase for React components.
+        format: ['camelCase', 'PascalCase'],
+        leadingUnderscore: 'allow',
+        trailingUnderscore: 'allow',
+      },
+      // Don't require object properties to conform to any convention.
+      {
+        selector: 'property',
+        format: null,
+      },
+      // However, require class members to be camelCase.
+      {
+        selector: 'memberLike',
+        modifiers: ['private', 'protected', 'public'],
+        format: ['camelCase'],
+      },
+      // Types should be PascalCase.
+      {
+        selector: 'typeLike',
+        format: ['PascalCase'],
+      },
+      // But sometimes we use enums like consts, especially when converting from JS.
+      {
+        selector: 'enum',
+        format: ['PascalCase', 'UPPER_CASE'],
+      },
+      {
+        selector: 'enumMember',
+        format: ['camelCase', 'PascalCase', 'UPPER_CASE'],
+        leadingUnderscore: 'allow',
+        trailingUnderscore: 'allow',
+      },
+    ],
+
+    // Require imports to be first in the file, as they're hoisted.
+    'import/first': 'error',
+
+    // Don't allow default exports.
+    'import/no-default-export': 'error',
+
+    // Have a convention around import order.
+    'import/order': 'error',
+
+    // jsx-a11y rules copied from create-react-app.
+    'jsx-a11y/accessible-emoji': 'error',
+    'jsx-a11y/alt-text': 'error',
+    'jsx-a11y/anchor-has-content': 'error',
+    'jsx-a11y/anchor-is-valid': [
+      'error',
+      {
+        aspects: ['noHref', 'invalidHref'],
+      },
+    ],
+    'jsx-a11y/aria-activedescendant-has-tabindex': 'error',
+    'jsx-a11y/aria-props': 'error',
+    'jsx-a11y/aria-proptypes': 'error',
+    'jsx-a11y/aria-role': ['error', { ignoreNonDOM: true }],
+    'jsx-a11y/aria-unsupported-elements': 'error',
+    'jsx-a11y/heading-has-content': 'error',
+    'jsx-a11y/iframe-has-title': 'error',
+    'jsx-a11y/img-redundant-alt': 'error',
+    'jsx-a11y/no-access-key': 'error',
+    'jsx-a11y/no-distracting-elements': 'error',
+    'jsx-a11y/no-redundant-roles': 'error',
+    'jsx-a11y/role-has-required-aria-props': 'error',
+    'jsx-a11y/role-supports-aria-props': 'error',
+    'jsx-a11y/scope': 'error',
+
+    // Require that code be formatted according to Prettier rules.
+    'prettier/prettier': [
+      'error',
+      prettierConfig,
+      {
+        // Rule should not be affected by a Prettier configuration file.
+        usePrettierrc: false,
+      },
+    ],
+
+    // Don't require event handlers to be prefixed with "handle".
+    'react/jsx-handler-names': 'off',
+
+    // We use TypeScript so don't usually need PropTypes.
+    'react/prop-types': 'off',
+
+    // Prevent stale closures in useEffect, useCallback, etc.
+    'react-hooks/exhaustive-deps': 'error',
+
+    // Enforce the Rules of Hooks.
+    'react-hooks/rules-of-hooks': 'error',
+  },
+
+  overrides: [
+    // Relax certain rules for tests.
+    {
+      files: ['cypress/**', '**/*.po.*', '**/*.spec.*', '**/*.test.*'],
+      env: {
+        jest: true,
+        mocha: true,
+      },
+      globals: {
+        cy: 'readable',
+        Cypress: 'readable',
+      },
+
+      rules: {
+        'no-console': 'off',
+      },
+    },
+
+    // TypeScript-specific rules. Somewhat inspired by tslint:recommended.
+    {
+      files: ['**/*.ts', '**/*.tsx'],
+      parser: '@typescript-eslint/parser',
+      parserOptions: {
+        ecmaVersion: 2018,
+        sourceType: 'module',
+        ecmaFeatures: {
+          jsx: true,
+        },
+      },
+
+      rules: {
+        // Checked by TypeScript and creates false positives with class method
+        // overloads.
+        'no-dupe-class-members': 'off',
+
+        // This rule has issues with the TypeScript parser, but tsc catches
+        // these sorts of errors anyway.
+        // See: https://github.com/typescript-eslint/typescript-eslint/issues/342
+        'no-undef': 'off',
+
+        'no-useless-constructor': 'off',
+        '@typescript-eslint/no-useless-constructor': 'error',
+
+        // Conflicts with TypeScript's noImplicitReturns option.
+        'no-useless-return': 'off',
+
+        // Require overloads to be grouped together
+        '@typescript-eslint/adjacent-overload-signatures': 'error',
+
+        // Use T[] over Array<T> for simple types
+        '@typescript-eslint/array-type': ['error', { default: 'array-simple' }],
+
+        // Prevent use of certain types that are almost always mistakes or have better alternatives.
+        // This configuration is based on the default, but excludes '{}' and 'object'.
+        '@typescript-eslint/ban-types': [
+          'error',
+          {
+            types: {
+              String: {
+                message: 'Use string instead',
+                fixWith: 'string',
+              },
+              Boolean: {
+                message: 'Use boolean instead',
+                fixWith: 'boolean',
+              },
+              Number: {
+                message: 'Use number instead',
+                fixWith: 'number',
+              },
+              Symbol: {
+                message: 'Use symbol instead',
+                fixWith: 'symbol',
+              },
+
+              Function: {
+                message: [
+                  'The `Function` type accepts any function-like value.',
+                  'It provides no type safety when calling the function, which can be a common source of bugs.',
+                  'It also accepts things like class declarations, which will throw at runtime as they will not be called with `new`.',
+                  'If you are expecting the function to accept certain arguments, you should explicitly define the function shape.',
+                ].join('\n'),
+              },
+
+              // object typing
+              Object: {
+                message: [
+                  'The `Object` type actually means "any non-nullish value", so it is marginally better than `unknown`.',
+                  '- If you want a type meaning "any object", you probably want `Record<string, unknown>` instead.',
+                  '- If you want a type meaning "any value", you probably want `unknown` instead.',
+                ].join('\n'),
+              },
+            },
+            extendDefaults: false,
+          },
+        ],
+
+        // Require 'as' type assertions.
+        '@typescript-eslint/consistent-type-assertions': [
+          'error',
+          { assertionStyle: 'as' },
+        ],
+
+        // Prefer interfaces over type literals (type T = { ... }).
+        '@typescript-eslint/consistent-type-definitions': [
+          'error',
+          'interface',
+        ],
+
+        // Require fields and methods to be explicitly labeled public, private, or protected.
+        // Exclude public constructors.
+        '@typescript-eslint/explicit-member-accessibility': [
+          'error',
+          { overrides: { constructors: 'no-public' } },
+        ],
+
+        // Require consistent ordering of fields, methods, and constructors.
+        '@typescript-eslint/member-ordering': [
+          'error',
+          {
+            default: [
+              'public-static-field',
+              'public-static-method',
+              'protected-static-field',
+              'protected-static-method',
+              'private-static-field',
+              'private-static-method',
+              'instance-field',
+              'constructor',
+              'instance-method',
+            ],
+          },
+        ],
+
+        // Prefer array literals over the array constructor.
+        'no-array-constructor': 'off',
+        '@typescript-eslint/no-array-constructor': 'error',
+
+        // Don't allow extra semi-colons.
+        'no-extra-semi': 'off',
+        '@typescript-eslint/no-extra-semi': 'error',
+
+        // Disallow empty interfaces, which are not useful.
+        '@typescript-eslint/no-empty-interface': 'error',
+
+        // Disallow invalid declarations of constructors on interfaces and 'new' methods on classes.
+        '@typescript-eslint/no-misused-new': 'error',
+
+        // TypeScript-aware unused variable rule.
+        'no-unused-vars': 'off',
+        '@typescript-eslint/no-unused-vars': [
+          'error',
+          {
+            // Allow unused function arguments
+            args: 'none',
+            // Allow destructuring like { a, ...b } = obj even if a is unused, to allow omitting fields.
+            ignoreRestSiblings: true,
+          },
+        ],
+
+        // Prefer ES6-style imports over 'require'.
+        '@typescript-eslint/no-var-requires': 'error',
+
+        // Prefer function types over callable interface types with no other members.
+        '@typescript-eslint/prefer-function-type': 'error',
+
+        // Prefer import instead of triple-slash reference comments.
+        '@typescript-eslint/triple-slash-reference': 'error',
+
+        // Warn when two overloads could be combined into one.
+        '@typescript-eslint/unified-signatures': 'error',
+      },
+    },
+  ],
+}