flow like the river

BACK_BACK/node_modules/htmlnano/lib/helpers.js

@@ -0,0 +1,41 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.isAmpBoilerplate = isAmpBoilerplate;
+exports.isComment = isComment;
+exports.isConditionalComment = isConditionalComment;
+exports.isStyleNode = isStyleNode;
+exports.extractCssFromStyleNode = extractCssFromStyleNode;
+const ampBoilerplateAttributes = ['amp-boilerplate', 'amp4ads-boilerplate', 'amp4email-boilerplate'];
+
+function isAmpBoilerplate(node) {
+  if (!node.attrs) {
+    return false;
+  }
+
+  for (const attr of ampBoilerplateAttributes) {
+    if (attr in node.attrs) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+function isComment(content) {
+  return (content || '').trim().startsWith('<!--');
+}
+
+function isConditionalComment(content) {
+  return (content || '').trim().startsWith('<!--[if');
+}
+
+function isStyleNode(node) {
+  return node.tag === 'style' && !isAmpBoilerplate(node) && 'content' in node && node.content.length > 0;
+}
+
+function extractCssFromStyleNode(node) {
+  return Array.isArray(node.content) ? node.content.join(' ') : node.content;
+}