/*
* Copyright 2015-2017 the original author or authors.
*
* All rights reserved. This program and the accompanying materials are
* made available under the terms of the Eclipse Public License v1.0 which
* accompanies this distribution and is available at
*
* http://www.eclipse.org/legal/epl-v10.html
*/
package org.junit.platform.engine;
import static java.lang.String.format;
import static java.util.stream.Collectors.joining;
import static org.junit.platform.engine.FilterResult.included;
import java.util.ArrayList;
import java.util.Collection;
import java.util.function.Predicate;
import org.junit.platform.commons.util.Preconditions;
/**
* Combines a collection of {@link Filter Filters} into a new filter that will
* include elements if and only if all of the filters in the specified collection
* include it.
*
* @since 1.0
*/
class CompositeFilter<T> implements Filter<T> {
@SuppressWarnings("rawtypes")
private static final Filter ALWAYS_INCLUDED_FILTER = new Filter() {
@Override
public FilterResult apply(Object obj) {
return ALWAYS_INCLUDED_RESULT;
}
@Override
public Predicate toPredicate() {
return obj -> true;
}
};
private static final FilterResult ALWAYS_INCLUDED_RESULT = included("Always included");
private static final FilterResult INCLUDED_BY_ALL_FILTERS = included("Element was included by all filters.");
@SuppressWarnings("unchecked")
static <T> Filter<T> alwaysIncluded() {
return ALWAYS_INCLUDED_FILTER;
}
private final Collection<Filter<T>> filters;
CompositeFilter(Collection<? extends Filter<T>> filters) {
this.filters = new ArrayList<>(Preconditions.notEmpty(filters, "filters must not be empty"));
}
@Override
public FilterResult apply(T element) {
// @formatter:off
return filters.stream()
.map(filter -> filter.apply(element))
.filter(FilterResult::excluded)
.findFirst()
.orElse(INCLUDED_BY_ALL_FILTERS);
// @formatter:on
}
@Override
public Predicate<T> toPredicate() {
// @formatter:off
return filters.stream()
.map(Filter::toPredicate)
.reduce(Predicate::and)
.get(); // it's safe to call get() here because the constructor ensures filters is not empty
// @formatter:on
}
@Override
public String toString() {
// @formatter:off
return filters.stream()
.map(Object::toString)
.map(value -> format("(%s)", value))
.collect(joining(" and "));
// @formatter:on
}
}