googletesting: Testing on the Toilet: Truth: a fluent assertion framework

Testing on the Toilet: Truth: a fluent assertion framework

Friday, December 19, 2014

by Dori Reuveni and Kurt Alfred Kluever

This article was adapted from a Google Testing on the Toilet (TotT) episode. You can download a printer-friendly version of this TotT episode and post it in your office. As engineers, we spend most of our time reading existing code, rather than writing new code.Truth is an open source, fluent testing framework for Java designed to make your test assertions and failure messages more readable.assertEquals("March", monthMap.get(3)); // JUnit
assertThat(monthMap).containsEntry(3, "March"); // TruthAnother benefit of Truth over JUnit is the addition of useful default failure messagesImmutableSet<String> colors = ImmutableSet.of("red", "green", "blue", "yellow");
assertTrue(colors.contains("orange")); // JUnit
assertThat(colors).contains("orange"); // TruthJUnit will not provide a useful failure messageTruth will provide a clear and concise failure messageAssertionError: <[red, green, blue, yellow]> should have contained <orange>Truth already supports specialized assertions for most of the common JDK typesTruth is also user-extensible: you can easily write a Truth subject to make fluent assertions about your own custom typesTruth's goal is not to replace JUnit assertions, but to improve the readability of complex assertions and their failure messagesTo get started with Truth, check outhttp://google.github.io/truth/