Hamcrest Optional

An extension to Java Hamcrest which provides matchers for java.util.Optional.

Usage

The artifact is available at Maven Central:

<dependency>
    <groupId>com.github.baev</groupId>
    <artifactId>hamcrest-optional</artifactId>
    <version>1.0</version>
</dependency>

hamcrest-optional provides four matchers for Optional: isEmpty(), isPresent(), hasValue(Object) and hasValue(Matcher).

isEmpty()

This matcher matches when the examined Optional contains no value.

import static com.github.npathai.hamcrestopt.OptionalMatchers.isEmpty;

Optional<Object> optional = Optional.empty();
assertThat(optional, isEmpty());

isPresent()

This matcher matches when the examined Optional contains a value.

import static com.github.npathai.hamcrestopt.OptionalMatchers.isPresent;

Optional<String> optional = Optional.of("dummy value");
assertThat(optional, isPresent());

hasValue(Object)

This matcher matches when the examined Optional contains a value that is logically equal to the specified object.

import static com.github.npathai.hamcrestopt.OptionalMatchers.hasValue;

Optional<String> optional = Optional.of("dummy value");
assertThat(optional, hasValue("dummy value"));

hasValue(Matcher)

This matcher matches when the examined Optional contains a value that satisfies the specified matcher.

import static com.github.npathai.hamcrestopt.OptionalMatchers.hasValue;
import static org.hamcrest.Matchers.startsWith;

Optional<String> optional = Optional.of("dummy value");
assertThat(optional, hasValue(startsWith("dummy")));

Development Guide

hamcrest-optional is build with Maven. If you want to contribute code then

• Please write a test for your change.
• Ensure that you don't break the build by running mvn test.
• Fork the repo and create a pull request. (See Understanding the GitHub Flow)

hamcrest-optional supports Travis CI for continuous integration. Your pull request is automatically build by Travis CI.