sourcemap-updater

A tool help to modify css and update sourcemap automatically.

Assume that you have a css (maybe generated via sass/postcss) and a corresponding sourcemap. If you want to modify the css (such as delete one declaration, change a prop value), you could modify directly, but the sourcemap would be inaccurate.

This lib will help you modify css (more convenient/powerful), and update sourcemap automatically. This means you no longer need to care about sourcemap when you modify css.

Installation and Usage

npm i --save sourcemap-updater

And then

const update = require('sourcemap-updater')
 
const res = update([
    readFileSync(`${__dirname}/res/concated.css`),
    readFileSync(`${__dirname}/res/concated.css.map`)
], {
    updater (str, node, type) {
        // for `prop-value`s, remove all newline of value.
        if (!type && node && node.prop) {
            node.value = node.value.replace(/\s*\n\s*/g, '')
            return node.toString() + ';'
        }
        return false
    }
})
 
writeFileSync(`${__dirname}/res/concated.css`, res.css)
writeFileSync(`${__dirname}/res/concated.css.map`, res.map)

API

update(data[, options])

• data is Array, data[0] is css content (String/Buffer), and data[1] is original sourcemap (String/Buffer/Object).

• options is Object. And options.updater is Function, options.file is String

  options.updater is like function(str, node, type){}, is the same as postcss/builder. You can use it to change css. For the return value of the func:

    1. If you return `false`, this part string would keep the same.
    2. If you return `String`, this `string` will be used (as the replacement).
    3. Otherwise, this part string will be deleted.
  

  options.file is String, the relative file path of the css content. It will be used when original sourcemap is invalid.

License

MIT