prettier-eslint-gallery

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Gallery Demo

Gallery Demo

What's this?

• JavaScript code formatting tool that support popular eslint style guides with zero configuration
• Command line and node.js API
• Gallery of popular eslint configurations for JavaScript styles so I can see how they look like and make a choice
• Easy/Automatic gallery generation from user's custom JavaScript input files (so they can see how their files will look like and vote!)

Why?

• Because I want to see how my code will look like when formatted to popular styles
• Because there are current formatting tools don't do a perfect work and we want to see how well they work and if we can improve it
• Because when choosing a style is not only important to know the rules but also to see how our code will look like !
• Because I want an easy to use command line tool to format code to popular styles that work as perfect as possible

Is this safe - ready to use ?

Yes! This project is not touching the code - it delegates all formatting to the very mature tools: eslint and prettier

Install & using in command line

You can install the tool globally:

 $ npm install -g prettier-eslint-gallery
 $ prettier-eslint-gallery --style standard --mode default --input "./src/**/*.js" --output ./src-formatted

Or locally:

 $ npm install --save-dev prettier-eslint-gallery
 $ node node_modules/prettier-eslint-gallery/src --style standard --input "./src/**/*.js" --output ./src-formatted

IMPORTANT if you want to format input files don't pass any --output argument and input files will be re-written

Using custom eslintrc

If you want to use your own custom .eslintrc file you can pass its path in --eslint-path instead of --style argument. In this case the file name needs to be eslintrc and and you are responsible of installing its dependencies:

  prettier-eslint-gallery --eslint-path ./eslintrc.js --input "./src/**/*.js"

nodejs API

Format files

Format several files and put the formatted versions in a separate folder:

const formatter = require('prettier-eslint-gallery')
const config = {
  input: './src/**/*.js',
  output: './src-formatted',
  style: 'airbnb',
};
formatter(config);

IMPORTANT if you want to re-write input files just don't pass the output property

Format a JavaScript code string

  const formatter = require('prettier-eslint-gallery')
  let config = {
      source: `var arr = [1,2,3].map(function(a){return a+1})`,
      style: 'walmart',
  }
  let result = formatter(config)

Configuration properties

The following are configuration properties that works both for the node.js API and for the CLI. In the case of the command line make sure you --property-name instead of --propertyName:

Name	Description
input	path to file or glob of files to format.
output	output folder where to put formatted files. If ommited input files will be overrided
style	One of popular styles like airbnb, eslint, fbjs, google, standard, walmart, etc.
eslintPath	path to a custom eslintrc. style will be ignored and user is responsible of installing custom eslint config dependencies.
debug	if true it will print debug info in stdout
buildGallery	will build gallery from input instead of formatting.
mode	see Modes section

Modes

• default: if first run prettier (inferring prettier config from eslint config) and then eslint --fix
• default-es5: Same as default, but disabling all eslint ecma6 rules. This causes that if you pass an es5 file as input it won't be fixed to use es6 constructions even if eslint config say so. For example, if the eslint-config defines prefer-arrow-callback: 'error' the rule will be disabled so the es5 input source will keep being es5
• onlyEslintFix: not using prettier, just eslint --fix. It still have some issues but we want to compare with 'default' modes to see how well do the work.

Generate your own gallery

If you want to generate the gallery using your own project's files and input to see how they will look like, just choose some files from your project and put them in folder my/sample/folderWithJsFiles and running the following command will generate a working gallery in gallery-output-folder. You need to open the folder using a static server since the application perform ajax requests:

 $ prettier-eslint-gallery --build-gallery --input my/sample/folderWithJsFiles --output gallery-output-folder
 $ static-server gallery-output-folder
 $ firefox  http://localhost:9080/gallery/index.html

Editors extensions

• Visual Studio Code : https://github.com/cancerberoSgx/prettier-eslint-gallery-vscode-extension

Research

• Research how well current formatting tools so the job
• Research heuristics to do better job
• see how well eslint --fix do the job and report issues.

Useful commands

Run tests and regenerate all output files:

npm test

Generate output and gallery:

 $ npm test
 $ rm gallery/index.html
 $ node src/gallery-generator/index
 $ static-server .
 $ firefox http://localhost:9080/gallery/index.html

issues / TODO

• probably we will need to rename this project to something more generic if we decide to use other tools besides prettier

• Research: make a tool to check each of the styles if they really work - check above. count formatting errors before an after and report for all - so we have an idea of how well --fix works and observe how it evolves

• Research - if we detect issues the following could be the cause: we are installing all the eslint plugins in the same project - but i notice that standard and airbnb require particular versions of plugins and they could be incompatible... try to separate individual projects in

• https://github.com/felixge/node-style-guide/blob/master/.eslintrc

• https://github.com/WordPress-Coding-Standards/eslint-config-wordpress/blob/master/index.js

• https://github.com/jquery/eslint-config-jquery

• https://github.com/bodil/eslint-config-cleanjs

• https://github.com/walmartlabs/eslint-config-defaults

• https://github.com/FormidableLabs/eslint-config-formidable

• then there are other that has nothing to do with style but with performance , security - should investigate: https://www.npmjs.com/search?q=eslint-c&page=1&ranking=popularity - do they work with --fix ?