Test-driven development for generated portable Javascript apps

With the advent of HTML 5, we can now develop rich web apps in Javascript that rival classical standalone apps. Nevertheless, developing in Javascript is still challenging and error prone because of the language's ambiguous semantics and quirks. In this paper, we advocate that the popular solution of using another language with better semantics and constructs is not enough. Developers should be provided with an IDE that eases the integration of Javascript libraries and enables testing an application across the many available Javascript interpreters. We introduce PharoJS,1 an infrastructure that allows Test-Driven Development (TDD) in Pharo Smalltalk of applications that ultimately run on a Javascript interpreter. PharoJS makes it possible to run interactive tests within the Pharo IDE, so as to fully exploit the debugging and development environment, while UI and libraries reside on the Javascript side.