Use tailwindcss/plugin for plugin declaration (#12)

* Implement customization for spinner class name and tailwind theme key

* Add test for custom spinner class name and tailwind theme key

* Improve readme with class name and tailwind theme key configuration

* Add test (skipped) for passing direct plugin require() result into tailwind config

* Use tailwindcss/plugin to create plugin function

Co-authored-by: kacah <deniss.paltovs@gmail.com>

Author: KACAH

index.js

@@ -1,5 +1,6 @@
 const _ = require('lodash')
 const flatten = require('flat')
+const plugin = require('tailwindcss/plugin')
 
 
 const FLATTEN_CONFIG = { delimiter: '-', maxDepth: 2 }
@@ -16,7 +17,7 @@ const prefixNegativeModifiers = function(base, modifier) {
 }
 
 
-module.exports = function (spinnerConfig = {}) {
+function pluginFactory(spinnerConfig = {}) {
   return function ({
     addUtilities, addComponents, addBase, addVariant,
     e, prefix, theme, variants, config,
@@ -118,3 +119,5 @@ module.exports = function (spinnerConfig = {}) {
     })
   }
 }
+
+module.exports = plugin.withOptions(pluginFactory)

test.js

@@ -26,7 +26,7 @@ const generatePluginCss = (testConfig = {}, pluginOptions) => {
     .then(result => result.css)
 }
 
-test.skip('can not pass direct require() into tailwind plugin', () => {
+test('can pass direct require() into tailwind plugin', () => {
   const sandboxConfig = {
     theme: {
       screens: { 'sm': '640px' },