Updating source files with the REST API

I am trying to find a way to update a source file with the REST API. Currently, I do the following in the SOAP API:

To load the new file I do the following:
aisManager.upload
aisManager.getNode

To get the projects that need to be updated and update them I do the following:
project.getActiveTasks
check to see if the task is an instanceof WSAssetTask
assetTask.getSourceAisNode
check to make sure that the soureNode.isContent
sourceNode.copyFrom(newNode)

This process works but we are wanting to replace this with a solution within the REST