doc test for copy_within

core/engine/src/object/builtins/jstypedarray.rs

@@ -137,7 +137,32 @@ impl JsTypedArray {
         BuiltinTypedArray::constructor(&self.inner.clone().into(), &[], context)
     }
 
+    /// Shallow copies part of this typed array to another location in the same typed 
+    /// array and returns this typed array without modifying its length.
+    /// 
     /// Returns `TypedArray.prototype.copyWithin()`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # use boa_engine::{JsResult, JsValue, object::{builtins::{JsUint8Array}}, Context};
+    /// # fn main() -> JsResult<()> {
+    ///
+    /// let context = &mut Context::default();
+    /// let array = JsUint8Array::from_iter(vec![1u8, 2u8, 3u8, 4u8, 5u8, 6u8, 7u8, 8u8], context)?;
+    /// array.copy_within(3, 1, Some(3), context)?;
+    /// assert_eq!(array.get(0, context)?, JsValue::new(1.0));
+    /// assert_eq!(array.get(1, context)?, JsValue::new(2.0));
+    /// assert_eq!(array.get(2, context)?, JsValue::new(3.0));
+    /// assert_eq!(array.get(3, context)?, JsValue::new(2.0));
+    /// assert_eq!(array.get(4, context)?, JsValue::new(3.0));
+    /// assert_eq!(array.get(5, context)?, JsValue::new(6.0));
+    /// assert_eq!(array.get(6, context)?, JsValue::new(7.0));
+    /// assert_eq!(array.get(7, context)?, JsValue::new(8.0));
+    ///
+    /// # Ok(())
+    /// # }
+    /// ```
     #[inline]
     pub fn copy_within<T>(
         &self,