Chapter 9. Testing your Application

	When the terrain disagrees with the map, trust the terrain.
	--Swiss Army Manual

Because a community fully committed to code sharing is building Node, and interoperability between modules is so important, it should come as no surprise that code testing tools and frameworks entered Node's ecosystem right after inception. Indeed, the normally parsimonious core Node team added the assert module early on, suggesting a recognition that testing is a fundamental part of the development process.

Testing software is a complicated and still mostly ill-defined activity. It is also essential to all phases of a non-trivial development project. The set of expectations accompanying the adjective "enterprise" when associated with "software" is a large one, comprising at least security, stability, consistency, predictability, and scale. Software is expected to anticipate and nimbly integrate multifaceted and unpredictable changes in data volume and shape, user expectations...