# 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
```json
{
    "extends": ["@thomaschaplin"]
}
```

#### package.json snippet
```json
"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](#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
```json
{
    "extends": ["@thomaschaplin"],
    "plugins": ["@typescript-eslint"],
    "parser": "@typescript-eslint/parser",
    "parserOptions": {
        "ecmaVersion": 6,
        "sourceType": "module",
        "ecmaFeatures": {
            "modules": true
        }
    }
}
```

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