Don't commit your ugly code.

A guide for writing cleaner code.

Troy M. Connor / troy0820

@troy0820

I ~~play~~ work with robots while writing JavaScript stuff at Emerging Technology Advisors

Ugly Code?

"Everyone knows that debugging is twice as hard as writing a program in the first place. So if you're as clever as you can be when you write it, how will you ever debug it?"

~ Brian Kernighan

ESLINT

Text

http://github.com/eslint

ESLINT

What do you need?

npm install -g eslint

3 ways to configure

//terminal

eslint --init

3 ways to configure

//.eslintrc.json

{
    "extends": "eslint: recommended"
}

3 ways to configure

//package.json

eslintConfig: {
    "extends": "eslint:recommended"
}

Environments

{
    "env": {
        "browser": true,
        "node": true
    }
}

http://eslint.org/docs/user-guide/configuring#specifying-environments

Plugins

//.eslintrc.js

"plugins": ['react']

Shareable eslint configs

eslint-config-airbnb
eslint-config-eta
eslint-config-trails
eslint-config-standard

Okay, you're set up......, or so you think

How do I use it?

//terminal

eslint . --ext .js

//package.json

{
    "scripts": {
        "lint": "eslint . --ext .js"
    }
}

npm run lint

//gulpfile.js

var gulp = require('gulp'),
    eslint = require('gulp-eslint');

gulp.task('lint', function () {
   return gulp.src(['**/*.js','!node_modules/**'])
          .pipe(eslint())
          .pipe(eslint.format())
          .pipe(eslint.failAfterError());
});

gulp.task('default', ['lint'], function () {
});

How do I use it?

//terminal

eslint {fileName} --fix

.editorConfig

//.editorConfig

# EditorConfig helps developers define and maintain consistent
# coding styles between different editors and IDEs
# editorconfig.org

root = true

[*]
# Change these settings to your own preference
indent_style = space
indent_size = 2

# We recommend you to keep these unchanged
end_of_line = lf
charset = utf-8
trim_trailing_whitespace = true
insert_final_newline = true

http://editorconfig.org/

Going to eslint 2.0

//removed rules
no-arrow-condition is replaced by a combination of no-confusing-arrow and no-constant-condition. Turn on both of these rules to get the same functionality as no-arrow-condition.
no-empty-label is replaced by no-labels with {"allowLoop": true, "allowSwitch": true} option.
space-after-keywords is replaced by keyword-spacing.
space-before-keywords is replaced by keyword-spacing.
space-return-throw-case is replaced by keyword-spacing.

{
    parserOptions: {
        ecmaVersion: 6
    }
}

//new rules in recommended 

constructor-super
no-case-declarations
no-class-assign
no-const-assign
no-dupe-class-members
no-empty-pattern
no-new-symbol
no-self-assign
no-this-before-super
no-unexpected-multiline
no-unused-labels