ViewsTest.java

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package org.glassfish.jersey.internal.util.collection;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.junit.Test;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.fail;

/**
 * @author Pavel Bucek (pavel.bucek at oracle.com)
 */
public class ViewsTest {

    @Test
    public void testTransformingListViewSize() {
        List<String> strings = new ArrayList<>();
        List<Integer> ints = Views.listView(strings, Integer::parseInt);

        assertEquals(strings.size(), ints.size());
        assertEquals(0, ints.size());
        strings.add("1");
        assertEquals(strings.size(), ints.size());
        assertEquals(1, ints.size());
        strings.remove("1");
        assertEquals(strings.size(), ints.size());
        assertEquals(0, ints.size());
    }

    @Test
    public void testTransformingListViewContent() {
        List<String> strings = new ArrayList<>();
        List<Integer> ints = Views.listView(strings, Integer::parseInt);

        strings.add("1");
        strings.add("2");
        strings.add("3");

        assertEquals(Integer.valueOf(1), ints.get(0));
        assertEquals(Integer.valueOf(2), ints.get(1));
        assertEquals(Integer.valueOf(3), ints.get(2));

        strings.remove("2");

        assertEquals(Integer.valueOf(1), ints.get(0));
        assertEquals(Integer.valueOf(3), ints.get(1));
    }

    @Test
    public void testTransformingListViewRemove() {
        List<String> strings = new ArrayList<>();
        List<Integer> ints = Views.listView(strings, Integer::parseInt);

        strings.add("1");
        strings.add("2");
        strings.add("3");

        ints.remove(Integer.valueOf(1));

        assertEquals(2, ints.size());
        assertEquals(Integer.valueOf(2), ints.get(0));
        assertEquals(Integer.valueOf(3), ints.get(1));
        assertEquals("2", strings.get(0));
        assertEquals("3", strings.get(1));
    }

    @Test
    public void testTransformingListViewModifyAdd() {
        List<String> strings = new ArrayList<>();
        List<Integer> ints = Views.listView(strings, Integer::parseInt);

        strings.add("1");
        strings.add("2");
        strings.add("3");

        try {
            ints.add(4);
        } catch (UnsupportedOperationException e) {
            return;
        }

        fail("UnsupportedOperationException expected.");
    }

    @Test
    public void testTransformingListViewModifySet() {
        List<String> strings = new ArrayList<>();
        List<Integer> ints = Views.listView(strings, Integer::parseInt);

        strings.add("1");
        strings.add("2");
        strings.add("3");

        try {
            ints.set(0, 4);
        } catch (UnsupportedOperationException e) {
            return;
        }

        fail("UnsupportedOperationException expected.");
    }

    @Test
    public void testTransformingMapViewSize() {
        Map<String, String> stringMap = new HashMap<>();
        Map<String, Integer> intMap = Views.mapView(stringMap, Integer::parseInt);

        assertEquals(stringMap.size(), intMap.size());
        assertEquals(0, intMap.size());
        stringMap.put("key1", "1");
        assertEquals(stringMap.size(), intMap.size());
        assertEquals(1, intMap.size());
        stringMap.remove("key1");
        assertEquals(stringMap.size(), intMap.size());
        assertEquals(0, intMap.size());
    }

    @Test
    public void testTransformingMapViewContent() {
        Map<String, String> stringMap = new HashMap<>();
        Map<String, Integer> intMap = Views.mapView(stringMap, Integer::parseInt);

        stringMap.put("key1", "1");
        stringMap.put("key2", "2");
        stringMap.put("key3", "3");

        assertEquals(Integer.valueOf(1), intMap.get("key1"));
        assertEquals(Integer.valueOf(2), intMap.get("key2"));
        assertEquals(Integer.valueOf(3), intMap.get("key3"));

        stringMap.remove("key2");

        assertEquals(Integer.valueOf(1), intMap.get("key1"));
        assertEquals(Integer.valueOf(3), intMap.get("key3"));
    }

    @Test
    public void testTransformingMapViewRemove() {
        Map<String, String> stringMap = new HashMap<>();
        Map<String, Integer> intMap = Views.mapView(stringMap, Integer::parseInt);

        stringMap.put("key1", "1");
        stringMap.put("key2", "2");
        stringMap.put("key3", "3");

        intMap.remove("key2");

        assertEquals(2, intMap.size());
        assertEquals(Integer.valueOf(1), intMap.get("key1"));
        assertEquals(Integer.valueOf(3), intMap.get("key3"));
        assertEquals("1", stringMap.get("key1"));
        assertEquals("3", stringMap.get("key3"));
    }

    @Test
    public void testTransformingMapViewModifyAdd() {
        Map<String, String> stringMap = new HashMap<>();
        Map<String, Integer> intMap = Views.mapView(stringMap, Integer::parseInt);

        stringMap.put("key1", "1");
        stringMap.put("key2", "2");
        stringMap.put("key3", "3");

        try {
            intMap.put("key4", 4);
        } catch (UnsupportedOperationException e) {
            return;
        }

        fail("UnsupportedOperationException expected.");
    }

    @Test
    public void testTransformingMapViewModifySet() {
        Map<String, String> stringMap = new HashMap<>();
        Map<String, Integer> intMap = Views.mapView(stringMap, Integer::parseInt);

        stringMap.put("key1", "1");
        stringMap.put("key2", "2");
        stringMap.put("key3", "3");

        try {
            intMap.entrySet().iterator().next().setValue(4);
        } catch (UnsupportedOperationException e) {
            return;
        }

        fail("UnsupportedOperationException expected.");
    }

    @Test
    public void testSetUnionViewNulls() {
        // should pass
        Set<Object> union = Views.setUnionView(Collections.emptySet(), Collections.emptySet());

        assertNotNull(union);

        // should fail
        try {
            Views.setUnionView(Collections.emptySet(), null);
            fail();
        } catch (NullPointerException e) {
            // expected.
        }

        // should fail
        try {
            Views.setUnionView(null, Collections.emptySet());
            fail();
        } catch (NullPointerException e) {
            // expected.
        }
    }

    @Test
    public void testSetUnionViewModify() {
        HashSet<String> set1 = new HashSet<>();
        HashSet<String> set2 = new HashSet<>();

        // should pass
        Set<Object> union = Views.setUnionView(set1, set2);

        assertNotNull(union);
        assertEquals(0, union.size());

        set1.add("test1");
        set2.add("test2");

        assertEquals(2, union.size());

        set1.clear();

        assertEquals(1, union.size());
    }

    @Test
    public void testSetDiffViewNulls() {
        // should pass
        Set<Object> diff = Views.setDiffView(Collections.emptySet(), Collections.emptySet());

        assertNotNull(diff);

        // should fail
        try {
            Views.setDiffView(Collections.emptySet(), null);
            fail();
        } catch (NullPointerException e) {
            // expected.
        }

        // should fail
        try {
            Views.setDiffView(null, Collections.emptySet());
            fail();
        } catch (NullPointerException e) {
            // expected.
        }
    }

    @Test
    public void testSetDiffViewModify() {
        HashSet<String> set1 = new HashSet<>();
        HashSet<String> set2 = new HashSet<>();

        // should pass
        Set<Object> diff = Views.setDiffView(set1, set2);

        assertNotNull(diff);
        assertEquals(0, diff.size());

        set1.add("test1");
        set1.add("test2");
        set1.add("test3");

        set2.add("test3");
        set2.add("test4");
        set2.add("test5");

        assertEquals(2, diff.size());

        set1.clear();

        assertEquals(0, diff.size());
    }

    @Test
    public void testSetDiffViewEmpty() {
        Set<String> set1 = Collections.emptySet();
        HashSet<String> set2 = new HashSet<>();

        // should pass
        Set<Object> diff = Views.setDiffView(set1, set2);

        assertNotNull(diff);
        assertEquals(0, diff.size());

        set2.add("test3");
        set2.add("test4");
        set2.add("test5");

        assertEquals(0, diff.size());

        set2.clear();

        assertEquals(0, diff.size());
    }
}