flow like the river

BACK_BACK/node_modules/htmlnano/lib/modules/mergeStyles.js

@@ -0,0 +1,42 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = mergeStyles;
+
+var _helpers = require("../helpers");
+
+/* Merge multiple <style> into one */
+function mergeStyles(tree) {
+  const styleNodes = {};
+  tree.match({
+    tag: 'style'
+  }, node => {
+    const nodeAttrs = node.attrs || {}; // Skip <style scoped></style>
+    // https://developer.mozilla.org/en/docs/Web/HTML/Element/style
+
+    if (nodeAttrs.scoped !== undefined) {
+      return node;
+    }
+
+    if ((0, _helpers.isAmpBoilerplate)(node)) {
+      return node;
+    }
+
+    const styleType = nodeAttrs.type || 'text/css';
+    const styleMedia = nodeAttrs.media || 'all';
+    const styleKey = styleType + '_' + styleMedia;
+
+    if (styleNodes[styleKey]) {
+      const styleContent = (node.content || []).join(' ');
+      styleNodes[styleKey].content.push(' ' + styleContent);
+      return '';
+    }
+
+    node.content = node.content || [];
+    styleNodes[styleKey] = node;
+    return node;
+  });
+  return tree;
+}