Calc a hash from generated code

[tetsuharuohzeki]

By this change, this plugin can calc a hash correctly even if only a "node" css file gathered by postcss is changed.

Fix #2

[tetsuharuohzeki]

@dacodekid how do you think about this?

[keithamus]

Thanks for your work here @saneyuki! Sorry for the delay in merging.

[brycewray]

I still observe the same behavior noted in #2. Is it dependent on the order in which this plugin is loaded in postcss.config.js (example below)? I tried it as the first item and see this behavior. I tried it as the last item and glitchy builds result online, despite good local test results.

const path = require('path')

module.exports = {
  plugins: [
    require('postcss-hash')({
      // algorithm: "sha512", // default = "md5"
      trim: 20,
      manifest: './_data/manifest.json',
      name: ({dir, name, hash, ext}) => path.join(dir, name + '-' + hash + ext)
    }),
    require('postcss-import'),
    require('tailwindcss'),
    require('postcss-preset-env')({ stage: 1 }),
    require('postcss-clean'),
  ],
}