Using TDD to build a stock alert application
Over the course of this book, we are going to be using TDD to build a simple stock alert application. The application will listen to stock updates from a source. The source can be anything—a server on the Internet, or a file on the hard drive, or something else. We will be able to define rules, and when the rule is matched, the application sends us an email or text message.
For example, we could define a rule as "If AAPL crosses the $550 level then send me an email". Once defined, the application will monitor updates and send an e-mail when the rule is matched.
Writing our first test
Enough talk. Let's get started with our application. What is a good place to start? From examining the application description ...