package org.hamcrest.core;

import org.hamcrest.Description;
import org.hamcrest.Matcher;
import org.hamcrest.TypeSafeDiagnosingMatcher;

public class Every<T> extends TypeSafeDiagnosingMatcher<Iterable<? extends T>> {
private final Matcher<? super T> matcher;

public Every(Matcher<? super T> matcher) {
this.matcher= matcher;

public boolean matchesSafely(Iterable<? extends T> collection, Description mismatchDescription) {
for (T t : collection) {
if (!matcher.matches(t)) {
mismatchDescription.appendText("an item ");
matcher.describeMismatch(t, mismatchDescription);
return false;
return true;

public void describeTo(Description description) {
description.appendText("every item is ").appendDescriptionOf(matcher);

* Creates a matcher for {@link Iterable}s that only matches when a single pass over the
* examined {@link Iterable} yields items that are all matched by the specified
* <code>itemMatcher</code>.
* For example:
* <pre>assertThat(Arrays.asList("bar", "baz"), everyItem(startsWith("ba")))</pre>

* @param itemMatcher
*the matcher to apply to every item provided by the examined {@link Iterable}

public static <U> Matcher<Iterable<? extends U>> everyItem(final Matcher<U> itemMatcher) {
return new Every<>(itemMatcher);