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backend/node_modules/svgo/plugins/mergeStyles.js

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+'use strict';
+
+/**
+ * @typedef {import('../lib/types').XastElement} XastElement
+ * @typedef {import('../lib/types').XastChild} XastChild
+ */
+
+const { visitSkip, detachNodeFromParent } = require('../lib/xast.js');
+
+exports.name = 'mergeStyles';
+exports.description = 'merge multiple style elements into one';
+
+/**
+ * Merge multiple style elements into one.
+ *
+ * @author strarsis <strarsis@gmail.com>
+ *
+ * @type {import('./plugins-types').Plugin<'mergeStyles'>}
+ */
+exports.fn = () => {
+  /**
+   * @type {?XastElement}
+   */
+  let firstStyleElement = null;
+  let collectedStyles = '';
+  /**
+   * @type {'text' | 'cdata'}
+   */
+  let styleContentType = 'text';
+
+  return {
+    element: {
+      enter: (node, parentNode) => {
+        // skip <foreignObject> content
+        if (node.name === 'foreignObject') {
+          return visitSkip;
+        }
+
+        // collect style elements
+        if (node.name !== 'style') {
+          return;
+        }
+
+        // skip <style> with invalid type attribute
+        if (
+          node.attributes.type != null &&
+          node.attributes.type !== '' &&
+          node.attributes.type !== 'text/css'
+        ) {
+          return;
+        }
+
+        // extract style element content
+        let css = '';
+        for (const child of node.children) {
+          if (child.type === 'text') {
+            css += child.value;
+          }
+          if (child.type === 'cdata') {
+            styleContentType = 'cdata';
+            css += child.value;
+          }
+        }
+
+        // remove empty style elements
+        if (css.trim().length === 0) {
+          detachNodeFromParent(node, parentNode);
+          return;
+        }
+
+        // collect css and wrap with media query if present in attribute
+        if (node.attributes.media == null) {
+          collectedStyles += css;
+        } else {
+          collectedStyles += `@media ${node.attributes.media}{${css}}`;
+          delete node.attributes.media;
+        }
+
+        // combine collected styles in the first style element
+        if (firstStyleElement == null) {
+          firstStyleElement = node;
+        } else {
+          detachNodeFromParent(node, parentNode);
+          /**
+           * @type {XastChild}
+           */
+          const child = { type: styleContentType, value: collectedStyles };
+          // TODO remove legacy parentNode in v4
+          Object.defineProperty(child, 'parentNode', {
+            writable: true,
+            value: firstStyleElement,
+          });
+          firstStyleElement.children = [child];
+        }
+      },
+    },
+  };
+};