Initial test for TaggedEventDistanceComparator

app/src/main/java/org/gdg/frisbee/android/api/model/Event.java

@@ -1,5 +1,7 @@
 package org.gdg.frisbee.android.api.model;
 
+import android.support.annotation.VisibleForTesting;
+
 import org.joda.time.DateTime;
 import org.joda.time.DateTimeZone;
 
@@ -60,6 +62,12 @@ public LatLng getLatLng() {
     public static class LatLng {
         double lat, lng;
 
+        @VisibleForTesting
+        public LatLng(double lat, double lng) {
+            this.lat = lat;
+            this.lng = lng;
+        }
+
         public double getLng() {
             return lng;
         }

app/src/test/java/org/gdg/frisbee/android/eventseries/TaggedEventDistanceComparatorTest.java

@@ -0,0 +1,72 @@
+package org.gdg.frisbee.android.eventseries;
+
+import android.location.Location;
+
+import org.gdg.frisbee.android.api.model.Event;
+import org.joda.time.DateTime;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.List;
+import java.util.Random;
+
+import static org.junit.Assert.assertEquals;
+import static org.mockito.Mockito.when;
+import static org.mockito.MockitoAnnotations.initMocks;
+
+public class TaggedEventDistanceComparatorTest {
+
+    @Mock
+    Event eventInMarch;
+    @Mock
+    Event eventInApril;
+    @Mock
+    Event eventWithLocation;
+    @Mock
+    Location location;
+
+    @Before
+    public void setup() {
+        initMocks(this);
+    }
+
+    @Test
+    public void givenEventsWithNoLocation_thenComparatorShouldSortUsingDates() {
+        when(eventInMarch.getStart()).thenReturn(new DateTime(2014, 3, 1, 0, 0));
+        when(eventInApril.getStart()).thenReturn(new DateTime(2014, 4, 1, 0, 0));
+        when(eventInMarch.getLatLng()).thenReturn(null);
+        when(eventInApril.getLatLng()).thenReturn(null);
+        when(eventWithLocation.getLatLng()).thenReturn(new Event.LatLng(41, 29));
+        when(location.getLatitude()).thenReturn(41d);
+        when(location.getLongitude()).thenReturn(29d);
+
+        TaggedEventDistanceComparator comparator = new TaggedEventDistanceComparator(location);
+
+        EventAdapter.Item eventInMarch =  new EventAdapter.Item(this.eventInMarch);
+        EventAdapter.Item eventInApril = new EventAdapter.Item(this.eventInApril);
+        EventAdapter.Item eventWithLocation = new EventAdapter.Item(this.eventWithLocation);
+
+        assertElementsOrderedLikeThis(comparator, eventInMarch, eventInApril, eventWithLocation, eventInApril);
+    }
+
+
+    private <T> void assertElementsOrderedLikeThis(
+        Comparator<? super T> comparator, T... elements) {
+        List<T> expectedOrder = Arrays.asList(elements);
+
+        List<T> shuffledAndSorted = new ArrayList<>(expectedOrder);
+        Collections.shuffle(shuffledAndSorted, new Random(0));
+        Collections.sort(shuffledAndSorted, comparator);
+        assertEquals(expectedOrder, shuffledAndSorted);
+
+        List<T> reversedAndSorted = new ArrayList<>(expectedOrder);
+        Collections.reverse(reversedAndSorted);
+        Collections.sort(reversedAndSorted, comparator);
+        assertEquals(expectedOrder, reversedAndSorted);
+    }
+}