diff --git a/app/src/main/java/info/nightscout/androidaps/db/BgReading.java b/app/src/main/java/info/nightscout/androidaps/db/BgReading.java
index 254c2a7318..6f87f232de 100644
--- a/app/src/main/java/info/nightscout/androidaps/db/BgReading.java
+++ b/app/src/main/java/info/nightscout/androidaps/db/BgReading.java
@@ -251,12 +251,16 @@ public class BgReading implements DataPointWithLabelInterface {
 
     // Copied from xDrip+
     public String calculateDirection(){
-        GlucoseStatus glucoseStatus = GlucoseStatus.getGlucoseStatusData();
-        if (glucoseStatus == null || glucoseStatus.prev_glucose != 0)
+        GlucoseStatus glucoseStatus = getGlucoseStatus();
+        double slope = 0;
+        if (glucoseStatus == null || glucoseStatus.prev_glucose == 0)
             return "??";
 
-//        double slope = glucoseStatus.delta / (glucoseStatus.previous_date - glucoseStatus.date);
-        double slope = (glucoseStatus.glucose - glucoseStatus.prev_glucose) / (glucoseStatus.previous_date - glucoseStatus.date);
+        // Avoid division by 0
+        if (glucoseStatus.date == glucoseStatus.previous_date)
+            slope = 0;
+        else
+            slope = (glucoseStatus.prev_glucose - glucoseStatus.glucose) / (glucoseStatus.previous_date - glucoseStatus.date);
         log.debug("Slope is :"+slope+" delta "+glucoseStatus.delta+" date difference "+(glucoseStatus.date - glucoseStatus.previous_date));
         double slope_by_minute = slope * 60000;
         String arrow = "NONE";
@@ -281,4 +285,9 @@ public class BgReading implements DataPointWithLabelInterface {
 
     }
 
+    // Used for testing purpose
+    protected GlucoseStatus getGlucoseStatus() {
+        return GlucoseStatus.getGlucoseStatusData();
+    }
+
 }
diff --git a/app/src/test/java/info/nightscout/androidaps/db/BgReadingTest.java b/app/src/test/java/info/nightscout/androidaps/db/BgReadingTest.java
index 3467205fba..4a43f9fb7a 100644
--- a/app/src/test/java/info/nightscout/androidaps/db/BgReadingTest.java
+++ b/app/src/test/java/info/nightscout/androidaps/db/BgReadingTest.java
@@ -4,9 +4,11 @@ import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.mockito.Mock;
+import org.mockito.Mockito;
 import org.powermock.core.classloader.annotations.PrepareForTest;
 import org.powermock.modules.junit4.PowerMockRunner;
 
+import java.util.Date;
 import java.util.logging.Logger;
 
 import info.AAPSMocker;
@@ -17,6 +19,7 @@ import info.nightscout.androidaps.plugins.iob.iobCobCalculator.GlucoseStatus;
 import info.nightscout.androidaps.utils.SP;
 
 import static org.junit.Assert.*;
+import static org.powermock.api.mockito.PowerMockito.doReturn;
 
 @RunWith(PowerMockRunner.class)
 @PrepareForTest({MainApp.class, Logger.class, L.class, SP.class})
@@ -54,10 +57,90 @@ public class BgReadingTest {
 
     }
 
+    @Test
+    public void dateTest(){
+        bgReading = new BgReading();
+        long now = System.currentTimeMillis();
+        bgReading.date = now;
+        Date nowDate = new Date(now);
+        assertEquals(now, bgReading.date(now).date);
+        assertEquals(now, bgReading.date(nowDate).date);
+    }
+
+    @Test
+    public void valueTest(){
+        bgReading = new BgReading();
+        double valueToSet = 81; // 4.5 mmol
+        assertEquals(81d, bgReading.value(valueToSet).value, 0.01d);
+    }
+
+    @Test
+    public void copyFromTest(){
+        bgReading = new BgReading();
+        BgReading copy = new BgReading();
+        bgReading.value = 81;
+        long now = System.currentTimeMillis();
+        bgReading.date = now;
+        copy.date = now;
+
+        copy.copyFrom(bgReading);
+
+        assertEquals(81, copy.value, 0.1d);
+        assertEquals(now, copy.date);
+        assertEquals(bgReading.directionToSymbol(), copy.directionToSymbol());
+    }
+
+    @Test
+    public void isEqualTest(){
+        bgReading = new BgReading();
+        BgReading copy = new BgReading();
+        bgReading.value = 81;
+        long now = System.currentTimeMillis();
+        bgReading.date = now;
+        copy.date = now;
+
+        copy.copyFrom(bgReading);
+
+        assertEquals(true, copy.isEqual(bgReading));
+        assertEquals(false, copy.isEqual(new BgReading()));
+    }
+
     @Test
     public void calculateDirection() throws Exception {
         assertEquals("??", bgReading.calculateDirection());
 
+        bgReading = new BgReading();
+        glucoseStatus = new GlucoseStatus();
+        glucoseStatus.glucose = 0;
+        glucoseStatus.prev_glucose = 0;
+        glucoseStatus.date = 1000L * 60 * 12;;
+        glucoseStatus.previous_date = 1000L * 60 * 6;
+        BgReading newReading = Mockito.spy(new BgReading());
+        doReturn(glucoseStatus).when(newReading).getGlucoseStatus();
+        assertEquals("??", newReading.calculateDirection());
+        glucoseStatus.glucose = 72;
+        glucoseStatus.prev_glucose = 10;
+        assertEquals("DoubleUp", newReading.calculateDirection());
+        glucoseStatus.glucose = 72;
+        glucoseStatus.prev_glucose = 55;
+        assertEquals("SingleUp", newReading.calculateDirection());
+        glucoseStatus.glucose = 72;
+        glucoseStatus.prev_glucose = 65;
+        assertEquals("FortyFiveUp", newReading.calculateDirection());
+        glucoseStatus.glucose = 72;
+        glucoseStatus.prev_glucose = 70;
+        assertEquals("Flat", newReading.calculateDirection());
+        glucoseStatus.glucose = 10;
+        glucoseStatus.prev_glucose = 72;
+        assertEquals("DoubleDown", newReading.calculateDirection());
+        glucoseStatus.glucose = 55;
+        glucoseStatus.prev_glucose = 72;
+        assertEquals("SingleDown", newReading.calculateDirection());
+        glucoseStatus.glucose = 65;
+        glucoseStatus.prev_glucose = 72;
+        assertEquals("FortyFiveDown", newReading.calculateDirection());
+
+
 
     }