com.oracle.bedrock.matchers.ConstantMatcher Maven / Gradle / Ivy
/*
* File: ConstantMatcher.java
*
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*
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* the Common Development and Distribution License 1.0 (the "License").
*
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*
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* file and include the License file LICENSE.txt.
*
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package com.oracle.bedrock.matchers;
import org.hamcrest.BaseMatcher;
import org.hamcrest.Description;
import org.hamcrest.Matcher;
import static org.hamcrest.core.IsEqual.equalTo;
/**
* A {@link Matcher} that can be used to record the success and failures of another {@link Matcher}.
*
* Typically this class is used for testing interaction with other {@link Matcher}s.
*
* Copyright (c) 2016. All Rights Reserved. Oracle Corporation.
* Oracle is a registered trademark of Oracle Corporation and/or its affiliates.
*
* @param the type of value being matched
*
* @author Brian Oliver
*/
public class ConstantMatcher extends BaseMatcher
{
/**
* The {@link Matcher} to use once the first value is provided.
*/
private Matcher matcher;
/**
* Constructs a {@link ConstantMatcher}.
*/
public ConstantMatcher()
{
this.matcher = null;
}
/**
* Obtains a {@link ConstantMatcher}.
*
* @param the type of values being matched
*
* @return a {@link ConstantMatcher}
*/
public static ConstantMatcher constant()
{
return new ConstantMatcher<>();
}
@Override
public boolean matches(Object o)
{
if (matcher == null)
{
matcher = equalTo((T) o);
return true;
}
else
{
return matcher.matches(o);
}
}
@Override
public void describeTo(Description description)
{
if (matcher == null)
{
description.appendText("is constant");
}
else
{
description.appendText("constantly matches using ");
matcher.describeTo(description);
}
}
}