Use local eslint in syntastic

Syntastic is one of my favorite vim plugins. It helps me find code issues in my code before committing. I heavily use it with rubocop for Ruby and eslint for JavaScript code.

npm-which

But by default, it uses the globally installed eslint, and I want it to use the locally installed one. So I wrote a small script, called npm-which that returns the path of the specified binary. If it can be found in the underlying node_modules binaries, it will return this one, otherwise it will revert to the global one.

The code takes advantage of the fact that every locally installed binary can be found in ./node_modules/.bin.

#!/usr/bin/env zsh

local npm_bin=$(npm bin)
local bin_name=$1
local local_path="${npm_bin}/${bin_name}"

[[ -f $local_path ]] && echo $local_path && return

echo $(which $bin_name)

You can find the up-to-date version here.

Update the vim config

I then have to tell syntastic the explicit path to the binary using the b:syntastic_javascript_eslint_exec variable. I'll use a local eslint if one is installed, or revert to the global one otherwise. I put that in a after/ftplugins/javascript.vim file in my vim directory.

let b:syntastic_javascript_eslint_exec = StrTrim(system('npm-which eslint'))

StrTrim is a custom vim method that will trim any starting and trailing whitespace from a vim string, and in my case the system call was returning a trailing weird ^@ char.

function! StrTrim(txt)
  return substitute(a:txt, '^\n*\s*\(.\{-}\)\n*\s*$', '\1', '')
endfunction

I can now use different eslint versions and configurations, directly in vim, depending on the current project I'm working on.

Edit: Matthew Smith packed all this into one neat Syntastic plugin. Thanks Matthew!

Tags : #npm, #vim, #eslint

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