package org.hamcrest.text;

import org.hamcrest.Description;
import org.hamcrest.Matcher;
import org.hamcrest.TypeSafeMatcher;

import static org.hamcrest.core.AnyOf.anyOf;
import static org.hamcrest.core.IsNull.nullValue;

/**
 
* Matches empty Strings (and null).
 
*/

public final class IsEmptyString extends TypeSafeMatcher<String> {
    
private static final IsEmptyString INSTANCE = new IsEmptyString();
    
@SuppressWarnings("unchecked")
    
private static final Matcher<String> NULL_OR_EMPTY_INSTANCE = anyOf(nullValue(), INSTANCE);

    
private IsEmptyString() { }

    
@Override
    
public boolean matchesSafely(String item) {
        
return item.equals("");
    
}

    
@Override
    
public void describeTo(Description description) {
        
description.appendText("an empty string");
    
}

    
/**
     
* Creates a matcher of {@link String} that matches when the examined string has zero length.
     
* For example:
     
* <pre>assertThat("", isEmptyString())</pre>
     
*
 

     
* @deprecated use is(emptyString()) instead
     
*/

    
@Deprecated
    
public static Matcher<String> isEmptyString() {
        
return emptyString();
    
}

    
/**
     
* Creates a matcher of {@link String} that matches when the examined string has zero length.
     
* For example:
     
* <pre>assertThat("", is(emptyString()))</pre>
     
*
 

     
*/

    
public static Matcher<String> emptyString() {
        
return INSTANCE;
    
}

    
/**
     
* Creates a matcher of {@link String} that matches when the examined string is <code>null</code>, or
     
* has zero length.
     
* For example:
     
* <pre>assertThat(((String)null), isEmptyOrNullString())</pre>
     
*
 

     
* @deprecated use is(emptyOrNullString()) instead
     
*
 

     
*/

    
@Deprecated
    
public static Matcher<String> isEmptyOrNullString() {
        
return emptyOrNullString();
    
}

    
/**
     
* Creates a matcher of {@link String} that matches when the examined string is <code>null</code>, or
     
* has zero length.
     
* For example:
     
* <pre>assertThat(((String)null), is(emptyOrNullString()))</pre>
     
*
 

     
*/

    
public static Matcher<String> emptyOrNullString() {
        
return NULL_OR_EMPTY_INSTANCE;
    
}
}