testdriven.com Wrangling quality out of chaos

FEST-Assert is another "assertThat" library that aims at making tests more readable. Here is an example:

Code:

import static org.fest.assertions.Assertions.assertThat; import org.testng.annotations.Test; public class SomeTest { @Test public void testApp() { assertThat(true).isTrue(); int result = 2 + 3; assertThat(result).as("calculation").isEqualTo(5); assertThat("Hello World").contains("World"); } }

We like this approach because:

1. Only one static import is needed (org.fest.assertions.Assertions.assertThat)

2. Allows us to use our IDE’s "auto-complete" feature: we only type "." and we get the possible assertion methods for the value passed to "assertThat"

3. We can chain related assertion methods:

Code:

assertThat(yoda).isInstanceOf(Jedi.class).isEqualTo(foundJedi).isNotEqualTo(possibleSith);

FEST-Assert can also be extended using Conditions. The following condition verifies that the characters in a String are in uppercase:

Code:

class UpperCaseCondition extends Condition<String> { private UpperCaseCondition(String description) { super(description); } @Override public boolean matches(String value) { if(isEmpty(value)) return false; return value.equals(value.toUpperCase()); } public static UpperCaseCondition isUpperCase() { return new UpperCaseCondition("Uppercase"); } }

This example shows how to use such condition:

Code:

assertThat("hello").as("Greeting").satisfies(isUpperCase());

which will fail with the message "[Greeting] expected:Uppercase but was:<’hello’>"

We would appreciate any feedback.

FEST project page.