Add purgecss to Next.js example

Author: adamwathan

examples/nextjs/components/Layout.jsx examples/nextjs/components/Layout.js

@@ -1,3 +1,7 @@
-@import "tailwindcss/base";
-@import "tailwindcss/components";
-@import "tailwindcss/utilities";
+/* purgecss start ignore */
+@import 'tailwindcss/base';
+/* purgecss end ignore */
+
+@import 'tailwindcss/components';
+
+@import 'tailwindcss/utilities';

examples/nextjs/css/tailwind.css

@@ -1,12 +1,13 @@
 const purgecss = require('@fullhuman/postcss-purgecss')({
-  content: ['./public/**/*.html'],
-  defaultExtractor: content => content.match(/[A-Za-z0-9-_:/]+/g) || []
+  content: ['./components/**/*.js', './pages/**/*.js'],
+  defaultExtractor: content => content.match(/[\w-/:]+(?<!:)/g) || [],
 })
 
 module.exports = {
   plugins: [
     require('postcss-import'),
     require('tailwindcss'),
     require('autoprefixer'),
-  ]
+    ...(process.env.NODE_ENV === 'production' ? [purgecss] : []),
+  ],
 }