Node JS avoid laboriously adding "use strict" to all my files

Question

So I want to enable strict mode for my project, but I have a lot of files and adding "use strict"; to the top of all of them would be a pain. I discovered the --use_strict CLI option for node which is awesome, but enables it for every single file inside my project directory, including all the third-party modules and their modules and I really don't want to go through correcting everybody's files, just mine.

So my question is, is there a way I could automate adding "use strict" to only my files?

Answer 1

You could write a script that opens each file and adds "use strict"\n to the beginning of it and write it back to disk.

Very untested example:

var fs = require("fs"),
   files = fs.readDirSync('./'),
   i;

for (i = 0; i < files.length; i += 1) {
  var fileContent = fs.readFileSync(files[i]).toString();
  fileContent = "\"use strict\"\n" + fileContent;
  fs.appendFileSync(files[i], fileContent);
}

Test for file[i] being a directory and move to a function to make it recursive if you need.

Inspired by https://stackoverflow.com/a/11987281/85010 and https://stackoverflow.com/a/10559790/85010.

Answer 2

use-strict-cli is a Node.js command line tool for adding/removing "use strict" statements within files found in given directories.

Instructions can be found here:

https://github.com/philidem/use-strict-cli

Example usage to add missing "use strict" statements:

use-strict ./src

Example usage to remove missing "use strict" statements:

use-strict ./src --remove

Answer 3

I suggest you adopt jshint in your work cycle and let it do this for you, amongst a bunch of other useful checks that will guarantee good-quality code.

I maintain a .jshintrc at the root of my web project with options:

{
  "immed": true,
  "latedef": true,
  "newcap": true,
  "nonew": true,
  "trailing": true,
  "multistr": true,
  "devel": true
}

You see that strict: true is in fact missing. This is because jshint has it set to true by default :)

Then you can have jshint setup to run as a git pre-commit hook or even better install it as a plugin for your code editor and fix the errors in real time as you code (e.g. SublimeLinter package for Sublime text 3)