buffer: add Buffer.copyBytesFrom(...)

Fixes: https://github.com/nodejs/node/issues/43862
PR-URL: https://github.com/nodejs/node/pull/46500
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>

lib/buffer.js

@@ -43,9 +43,13 @@ const {
   StringPrototypeTrim,
   SymbolSpecies,
   SymbolToPrimitive,
+  TypedArrayPrototypeGetBuffer,
   TypedArrayPrototypeGetByteLength,
+  TypedArrayPrototypeGetByteOffset,
   TypedArrayPrototypeFill,
+  TypedArrayPrototypeGetLength,
   TypedArrayPrototypeSet,
+  TypedArrayPrototypeSlice,
   Uint8Array,
   Uint8ArrayPrototype,
 } = primordials;
@@ -330,6 +334,48 @@ Buffer.from = function from(value, encodingOrOffset, length) {
   );
 };
 
+/**
+ * Creates the Buffer as a copy of the underlying ArrayBuffer of the view
+ * rather than the contents of the view.
+ * @param {TypedArray} view
+ * @param {number} [offset]
+ * @param {number} [length]
+ * @returns {Buffer}
+ */
+Buffer.copyBytesFrom = function copyBytesFrom(view, offset, length) {
+  if (!isTypedArray(view)) {
+    throw new ERR_INVALID_ARG_TYPE('view', [ 'TypedArray' ], view);
+  }
+
+  const viewLength = TypedArrayPrototypeGetLength(view);
+  if (viewLength === 0) {
+    return Buffer.alloc(0);
+  }
+
+  if (offset !== undefined || length !== undefined) {
+    if (offset !== undefined) {
+      validateInteger(offset, 'offset', 0);
+      if (offset >= viewLength) return Buffer.alloc(0);
+    } else {
+      offset = 0;
+    }
+    let end;
+    if (length !== undefined) {
+      validateInteger(length, 'length', 0);
+      end = offset + length;
+    } else {
+      end = viewLength;
+    }
+
+    view = TypedArrayPrototypeSlice(view, offset, end);
+  }
+
+  return fromArrayLike(new Uint8Array(
+    TypedArrayPrototypeGetBuffer(view),
+    TypedArrayPrototypeGetByteOffset(view),
+    TypedArrayPrototypeGetByteLength(view)));
+};
+
 // Identical to the built-in %TypedArray%.of(), but avoids using the deprecated
 // Buffer() constructor. Must use arrow function syntax to avoid automatically
 // adding a `prototype` property and making the function a constructor.