eslint-config

Preferring ES6, readability and low ambiguities. Extends the recommended ruleset with some useful additions.

Setup Guide

Follow the below steps to setup ESLint using this custom configuration

JavaScript

• npm install eslint --save-dev
• npm install @thomaschaplin/eslint-config --save-dev
• touch .eslintrc
• Add the below snippet into your .eslintrc file
• Add the below script snippet into your package.json file

.eslintrc snippet

{
    "extends": ["@thomaschaplin"]
}

package.json snippet

"scripts": {
    "lint:js": "./node_modules/eslint/bin/eslint.js 'src/**/*.js'",
    "lintFull": "npm run lint:js -- --fix"
}

TypeScript

Follow all of the steps for the JavaScript setup

• npm install typescript --save-dev
• npm install @typescript-eslint/eslint-plugin --save-dev
• npm install @typescript-eslint/parser --save-dev
• Add the below snippet into your .eslintrc file
• Add the below script snippet into your package.json file

.eslintrc snippet

{
    "extends": ["@thomaschaplin"],
    "plugins": ["@typescript-eslint"],
    "parser": "@typescript-eslint/parser",
    "parserOptions": {
        "ecmaVersion": 6,
        "sourceType": "module",
        "ecmaFeatures": {
            "modules": true
        }
    }
}

package.json snippet

"scripts": {
    "lint:ts": "./node_modules/eslint/bin/eslint.js 'src/**/*.ts'",
    "lintFull": "npm run lint:ts -- --fix"
}

Rules in detail

Environments: node, es6, browser

Unless noted, all rules are errors.

| Rule | Description | | ------------------------------------------------------------------------------------------------------------------ | -------------------------------------------------------------------------------------- | | arrow-parens | Always wrap function arguments in brackets. | | brace-style | Curly brackets start after the keyword, not underneath. | | comma-dangle | Dangling commas in multiline objects, functions, arrays. | | complexity | Maximum cyclomatic complexity of 3 to enforce highly maintaineable code (warning). | | curly | Curly brackets after if statements to avoid ambiguity when line breaks occur. | | eol-last | Empty line at the end of the file. | | func-call-spacing | Brackets () to invoke a function have to stand right next to the function name. | | global-require | require() statements should be at the top of the file (warning). | | linebreak-style | UNIX linebreaks. | | no-await-in-loop | Disallow await in loops (should use Promise.all() instead). | | no-default-export | Only allow named exports for increased consistency and clarity when importing modules. | | no-floating-decimal | Numbers have to be clear, i.e. 0.4 instead of .4. | | no-implicit-coercion | Converting types from one to another have to be explicit. | | no-lone-blocks | No curly brackets unless necessary. | | no-lonely-if | Use else if instead of a lonely if wrapped inside an else. | | no-loop-func | Functions cannot be declared inside loops, they should be declared outside. | | no-template-curly-in-string | Avoid confusion whether a string is templated or not. | | no-throw-literal | Throw errors explicitly, not just strings or values. | | no-var | Use ES6 block-scopedconst and let, never var. | | one-var | Don't declare multiple variables in one line. | | prefer-const | let should only be used where reassignment is necessary. | | prefer-promise-reject-errors | Promises should be rejected with a clear error, not a simple value. | | prefer-spread | Use ES6 spread operator instead of difficult to understand ES5 .apply(). | | prefer-template | Use template strings instead of string concatenation (warning). | | quotes | Use unescaped double quotes. | | require-await | async functions should perform an await, otherwise async keyword is unnecessary. | | semi | Don't use semicolons. | | yoda | Don't use unintuitive conditions. |