Move arrayEquals to utils.js

src/observer.js

@@ -1,30 +1,5 @@
 import Events from './events.js';
-
-// The Observer implementation assumed this array equality function
-// was a member of Array prototype (called 'equals'). This has now
-// been moved here instead.
-const arrayEquals = (a, b) => {
-    if (!a || !b) {
-        return false;
-    }
-
-    const l = a.length;
-
-    if (l !== b.length) {
-        return false;
-    }
-
-    for (let i = 0; i < l; i++) {
-        if (a[i] instanceof Array && b[i] instanceof Array) {
-            if (!arrayEquals(a[i], b[i])) {
-                return false;
-            }
-        } else if (a[i] !== b[i]) {
-            return false;
-        }
-    }
-    return true;
-};
+import { arrayEquals } from './utils.js';
 
 /**
  * The Observer class is used to observe and manage changes to an object. It allows for tracking

src/utils.js

@@ -0,0 +1,41 @@
+/**
+ * Determines whether two arrays are deeply equal. Two arrays are considered equal if they have the
+ * same length and corresponding elements are equal. This function also supports nested arrays,
+ * comparing them recursively.
+ *
+ * @param {Array} a - The first array to compare.
+ * @param {Array} b - The second array to compare.
+ * @returns {boolean} - Returns `true` if the arrays are deeply equal, otherwise `false`.
+ *
+ * @example
+ * arrayEquals([1, 2, 3], [1, 2, 3]); // true
+ * arrayEquals([1, 2, 3], [3, 2, 1]); // false
+ * arrayEquals([1, [2, 3]], [1, [2, 3]]); // true
+ * arrayEquals([1, [2, 3]], [1, [3, 2]]); // false
+ * arrayEquals([1, 2, 3], null); // false
+ * arrayEquals(null, null); // false
+ */
+const arrayEquals = (a, b) => {
+    if (!a || !b) {
+        return false;
+    }
+
+    const l = a.length;
+
+    if (l !== b.length) {
+        return false;
+    }
+
+    for (let i = 0; i < l; i++) {
+        if (a[i] instanceof Array && b[i] instanceof Array) {
+            if (!arrayEquals(a[i], b[i])) {
+                return false;
+            }
+        } else if (a[i] !== b[i]) {
+            return false;
+        }
+    }
+    return true;
+};
+
+export { arrayEquals };