critical css

critical-css.js

@@ -0,0 +1,30 @@
+const path = require('path');
+const fs = require('fs');
+const tmpDir = require('os').tmpdir();
+const request = require('request');
+const criticalcss = require('criticalcss');
+
+const cssUrl =
+  'https://awesome-docker.netlify.com/16dc205b0ca3044a54bfb5fc8384de31.css';
+const cssPath = path.join(tmpDir, 'style.css');
+request(cssUrl)
+  .pipe(fs.createWriteStream(cssPath))
+  .on('close', () => {
+    criticalcss.getRules(cssPath, (err, output) => {
+      if (err) {
+        throw new Error(err);
+      } else {
+        criticalcss.findCritical(
+          'https://awesome-docker.netlify.com/',
+          { rules: JSON.parse(output) },
+          (err, output) => {
+            if (err) {
+              throw new Error(err);
+            } else {
+              console.log(output);
+            }
+          }
+        );
+      }
+    });
+  });