Added ArrayBuffer support (#36)

* Added ArrayBuffer support

Added support for loading ArrayBuffer type

* Define arrayBuf outside of the conditional for scoping

---------

Co-authored-by: Jordan Matelsky <j6k4m8@users.noreply.github.com>

index.js

@@ -103,8 +103,16 @@ class npyjs {
         Loads an array from a stream of bytes.
         */
         fetchArgs = fetchArgs || {};
-        const resp = await fetch(filename, { ...fetchArgs });
-        const arrayBuf = await resp.arrayBuffer();
+        let arrayBuf;
+        // If filename is ArrayBuffer
+        if (filename instanceof ArrayBuffer) {
+            arrayBuf = filename;
+        }
+        // If filename is a file path
+        else {
+            const resp = await fetch(filename, { ...fetchArgs });
+            arrayBuf = await resp.arrayBuffer();
+        }
         const result = this.parse(arrayBuf);
         if (callback) {
             return callback(result);