Very small GopherJS app to demonstrate local file manipulation in the browser.
The webapp allows you to "upload" a file, whose content gets converted to uppercase and offering a "download" of the the result, all done locally in the browser.
To check it out just serve it through gopherjs:
gopherjs serve
And navigate to http://localhost:8080/github.com/reusing-code/jsfile/ (URL depends on the location of the source files in relation to the GOPATH.)