Change order of parameters of provision().

dist/dfu.js

@@ -162,11 +162,11 @@
         return view;
     }
 
-    function provision(device, arrayBuffer, imageType, crc) {
+    function provision(device, arrayBuffer, crc, imageType) {
         return new Promise(function(resolve, reject) {
             var versionChar = null;
-            imageType = imageType || ImageType.Application;
             initPacket.crc = crc || 0xFFFF; // Not used in mbed/ older bootloader revisions.
+            imageType = imageType || ImageType.Application;
 
             connect(device)
             .then(function(chars) {

example_node.js

@@ -43,7 +43,7 @@ dfu.findDevice({ services: [0x180D] })
     log("file length: " + buffer.byteLength);
     var crc = crc16(buffer);
 
-    return dfu.provision(device, buffer, 4, crc);
+    return dfu.provision(device, buffer, crc);
 })
 .then(() => process.exit())
 .catch(error => {

example_web.html

@@ -71,7 +71,7 @@
                     log("downloaded length: " + buffer.byteLength);
                     var crc = crc16(buffer);
 
-                    return dfu.provision(device, buffer, 4, crc);
+                    return dfu.provision(device, buffer, crc); // dfu.ImageType.Application is the default value for the fourth parameter. Specify this if you want to upload a softdevice/bootloader.
                 })
                 .then(() => {
                     log('dfu complete');