core/tests/utiltests/src/com/android/internal/util/PredicatesTest.java

/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.internal.util;

import junit.framework.TestCase;

import java.util.ArrayList;
import java.util.Collections;

public class PredicatesTest extends TestCase {

    private static final Predicate<Object> TRUE = new Predicate<Object>() {
        public boolean apply(Object o) {
            return true;
        }
    };

    private static final Predicate<Object> FALSE = new Predicate<Object>() {
        public boolean apply(Object o) {
            return false;
        }
    };

    public void testAndPredicate_AllConditionsTrue() throws Exception {
        assertTrue(Predicates.and(newArrayList(TRUE)).apply(null));
        assertTrue(Predicates.and(newArrayList(TRUE, TRUE)).apply(null));
    }

    public void testAndPredicate_AtLeastOneConditionIsFalse() throws Exception {
        assertFalse(Predicates.and(newArrayList(FALSE, TRUE, TRUE)).apply(null));
        assertFalse(Predicates.and(newArrayList(TRUE, FALSE, TRUE)).apply(null));
        assertFalse(Predicates.and(newArrayList(TRUE, TRUE, FALSE)).apply(null));
    }

    public void testOrPredicate_AllConditionsTrue() throws Exception {
        assertTrue(Predicates.or(newArrayList(TRUE, TRUE, TRUE)).apply(null));
    }

    public void testOrPredicate_AllConditionsFalse() throws Exception {
        assertFalse(Predicates.or(newArrayList(FALSE, FALSE, FALSE)).apply(null));
    }

    public void testOrPredicate_AtLeastOneConditionIsTrue() throws Exception {
        assertTrue(Predicates.or(newArrayList(TRUE, FALSE, FALSE)).apply(null));
        assertTrue(Predicates.or(newArrayList(FALSE, TRUE, FALSE)).apply(null));
        assertTrue(Predicates.or(newArrayList(FALSE, FALSE, TRUE)).apply(null));
    }

    public void testNotPredicate() throws Exception {
        assertTrue(Predicates.not(FALSE).apply(null));
        assertFalse(Predicates.not(TRUE).apply(null));
    }

    private static <E> ArrayList<E> newArrayList(E... elements) {
        ArrayList<E> list = new ArrayList<E>();
        Collections.addAll(list, elements);
        return list;
    }

}