Java Reference
In-Depth Information
Test coverage and
development
I don't think anybody tests enough of anything.
—James Gosling
This chapter covers
Measuring test coverage
■
Writing testable code
■
Practicing test-driven development
■
In the previous chapters, we introduced testing software and started exploring test-
ing with
JU
nit. We also presented various test methodologies.
Now that we're writing test cases, it's time to measure how good these tests are
by using a
test coverage
tool to report what code is exercised by the tests and what
code is not. We also discuss how to write code that's easy to test. We finish by look-
ing at test-driven development (
TDD
).
5.1
Measuring test coverage
Writing unit tests gives you the confidence to change and refactor an application.
As you make changes, you run tests, which gives you immediate feedback on new
features under test and whether your changes break existing tests. The issue is that
these changes may still break existing untested functionality.
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