package org.hamcrest.core;

import org.hamcrest.BaseMatcher;
import org.hamcrest.Description;
import org.hamcrest.Matcher;

import static org.hamcrest.core.IsEqual.equalTo;

/**
 
* Decorates another Matcher, retaining the behaviour but allowing tests
 
* to be slightly more expressive.
 
*
 
* For example:
  
assertThat(cheese, equalTo(smelly))
 
*
          
vs.
  
assertThat(cheese, is(equalTo(smelly)))
 
*/

public class Is<T> extends BaseMatcher<T> {
    
private final Matcher<T> matcher;

    
public Is(Matcher<T> matcher) {
        
this.matcher = matcher;
    
}

    
@Override
    
public boolean matches(Object arg) {
        
return matcher.matches(arg);
    
}

    
@Override
    
public void describeTo(Description description) {
        
description.appendText("is ").appendDescriptionOf(matcher);
    
}

    
@Override
    
public void describeMismatch(Object item, Description mismatchDescription) {
        
matcher.describeMismatch(item, mismatchDescription);
    
}

    
/**
     
* Decorates another Matcher, retaining its behaviour, but allowing tests
     
* to be slightly more expressive.
     
* For example:
     
* <pre>assertThat(cheese, is(equalTo(smelly)))</pre>
     
* instead of:
     
* <pre>assertThat(cheese, equalTo(smelly))</pre>
     
*
 

     
*/

    
public static <T> Matcher<T> is(Matcher<T> matcher) {
        
return new Is<>(matcher);
    
}

    
/**
     
* A shortcut to the frequently used <code>is(equalTo(x))</code>.
     
* For example:
     
* <pre>assertThat(cheese, is(smelly))</pre>
     
* instead of:
     
* <pre>assertThat(cheese, is(equalTo(smelly)))</pre>
     
*
 

     
*/

    
public static <T> Matcher<T> is(T value) {
        
return is(equalTo(value));
    
}

    
/**
     
* A shortcut to the frequently used <code>is(instanceOf(SomeClass.class))</code>.
     
* For example:
     
* <pre>assertThat(cheese, isA(Cheddar.class))</pre>
     
* instead of:
     
* <pre>assertThat(cheese, is(instanceOf(Cheddar.class)))</pre>
     
*
 

     
*/

    
public static <T> Matcher<T> isA(Class<?> type) {
        
return is(IsInstanceOf.<T>instanceOf(type));
    
}
}