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node_modules/svgo/plugins/sortDefsChildren.js

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+'use strict';
+
+exports.type = 'visitor';
+exports.name = 'sortDefsChildren';
+exports.active = true;
+exports.description = 'Sorts children of <defs> to improve compression';
+
+/**
+ * Sorts children of defs in order to improve compression.
+ * Sorted first by frequency then by element name length then by element name (to ensure grouping).
+ *
+ * @author David Leston
+ *
+ * @type {import('../lib/types').Plugin<void>}
+ */
+exports.fn = () => {
+  return {
+    element: {
+      enter: (node) => {
+        if (node.name === 'defs') {
+          /**
+           * @type {Map<string, number>}
+           */
+          const frequencies = new Map();
+          for (const child of node.children) {
+            if (child.type === 'element') {
+              const frequency = frequencies.get(child.name);
+              if (frequency == null) {
+                frequencies.set(child.name, 1);
+              } else {
+                frequencies.set(child.name, frequency + 1);
+              }
+            }
+          }
+          node.children.sort((a, b) => {
+            if (a.type !== 'element' || b.type !== 'element') {
+              return 0;
+            }
+            const aFrequency = frequencies.get(a.name);
+            const bFrequency = frequencies.get(b.name);
+            if (aFrequency != null && bFrequency != null) {
+              const frequencyComparison = bFrequency - aFrequency;
+              if (frequencyComparison !== 0) {
+                return frequencyComparison;
+              }
+            }
+            const lengthComparison = b.name.length - a.name.length;
+            if (lengthComparison !== 0) {
+              return lengthComparison;
+            }
+            if (a.name !== b.name) {
+              return a.name > b.name ? -1 : 1;
+            }
+            return 0;
+          });
+        }
+      },
+    },
+  };
+};