1 files changed, 65 insertions, 0 deletions
diff --git a/src/bun.js/builtins/js/JSBufferConstructor.js b/src/bun.js/builtins/js/JSBufferConstructor.js
new file mode 100644
index 000000000..9a3f0e1b7
--- /dev/null
+++ b/src/bun.js/builtins/js/JSBufferConstructor.js
@@ -0,0 +1,65 @@
+/*
+ * Copyright 2022 Codeblog Corp. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+// ^ that comment is required or the builtins generator will have a fit.
+
+
+function from(items) {
+  "use strict";
+
+  if (!@isConstructor(this))
+        @throwTypeError("Buffer.from requires |this| to be a constructor");
+
+
+    // TODO: figure out why private symbol not found
+    if (typeof items === 'string' || (typeof items === 'object' && items && (items instanceof ArrayBuffer || items instanceof SharedArrayBuffer))) {
+        switch (@argumentCount()) {
+            case 1: {
+                return new this(items);
+            }
+            case 2: {
+                return new this(items, @argument(1));
+            }
+            default: {
+                return new this(items, @argument(1), @argument(2));
+            }
+        }
+    }
+
+
+    var arrayLike = @toObject(items, "Buffer.from requires an array-like object - not null or undefined");
+
+    // Buffer-specific fast path: 
+    // - uninitialized memory
+    // - use .set
+    if (@isTypedArrayView(arrayLike)) {
+        var length = @typedArrayLength(arrayLike);
+        var result = this.allocUnsafe(length);
+        result.set(arrayLike);
+        return result;
+    } 
+
+    return @tailCallForwardArguments(@Uint8Array.from, this);
+}