fix MidnightTime crash + tests

app/src/main/java/info/nightscout/androidaps/utils/MidnightTime.java

@@ -5,7 +5,7 @@ import android.util.LongSparseArray;
 import java.util.Calendar;
 
 public class MidnightTime {
-    private static LongSparseArray times = new LongSparseArray();
+    private static final LongSparseArray<Long> times = new LongSparseArray<>();
 
     private static long hits = 0;
     private static long misses = 0;
@@ -20,20 +20,23 @@ public class MidnightTime {
     }
 
     public static long calc(long time) {
-        Long m = (Long) times.get(time);
-        if (m != null) {
-            ++hits;
-            return m;
+        Long m;
+        synchronized (times) {
+            m = times.get(time);
+            if (m != null) {
+                ++hits;
+                return m;
+            }
+            Calendar c = Calendar.getInstance();
+            c.setTimeInMillis(time);
+            c.set(Calendar.HOUR_OF_DAY, 0);
+            c.set(Calendar.MINUTE, 0);
+            c.set(Calendar.SECOND, 0);
+            c.set(Calendar.MILLISECOND, 0);
+            m = c.getTimeInMillis();
+            times.append(time, m);
+            ++misses;
         }
-        Calendar c = Calendar.getInstance();
-        c.setTimeInMillis(time);
-        c.set(Calendar.HOUR_OF_DAY, 0);
-        c.set(Calendar.MINUTE, 0);
-        c.set(Calendar.SECOND, 0);
-        c.set(Calendar.MILLISECOND, 0);
-        m = c.getTimeInMillis();
-        times.append(time, m);
-        ++misses;
         return m;
     }
 

app/src/test/java/info/nightscout/androidaps/utils/MidnightTimeTest.java

@@ -0,0 +1,62 @@
+package info.nightscout.androidaps.utils;
+
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.powermock.core.classloader.annotations.PrepareForTest;
+import org.powermock.modules.junit4.PowerMockRunner;
+
+import java.util.Calendar;
+import java.util.Date;
+
+import info.AAPSMocker;
+import info.nightscout.androidaps.MainApp;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * Created by mike on 20.11.2017.
+ */
+@RunWith(PowerMockRunner.class)
+@PrepareForTest({Calendar.class})
+public class MidnightTimeTest {
+
+    @Test
+    public void calc() {
+        // We get real midnight
+        long now = DateUtil.now();
+        Assert.assertTrue(now >= MidnightTime.calc());
+        Calendar c = Calendar.getInstance();
+        c.setTimeInMillis(MidnightTime.calc());
+        Assert.assertEquals(c.get(Calendar.HOUR_OF_DAY), 0);
+        Assert.assertEquals(c.get(Calendar.MINUTE), 0);
+        Assert.assertEquals(c.get(Calendar.SECOND), 0);
+        Assert.assertEquals(c.get(Calendar.MILLISECOND), 0);
+    }
+
+    @Test
+    public void calc_time() {
+        // We get real midnight
+        long now = DateUtil.now();
+        long midnight = MidnightTime.calc(now);
+        Assert.assertTrue(now >= midnight);
+        Calendar c = Calendar.getInstance();
+        c.setTimeInMillis(MidnightTime.calc(now));
+        Assert.assertEquals(c.get(Calendar.HOUR_OF_DAY), 0);
+        Assert.assertEquals(c.get(Calendar.MINUTE), 0);
+        Assert.assertEquals(c.get(Calendar.SECOND), 0);
+        Assert.assertEquals(c.get(Calendar.MILLISECOND), 0);
+        // Assure we get the same time from cache
+        Assert.assertEquals(midnight, MidnightTime.calc(now));
+    }
+
+    @Test
+    public void log() {
+        long now = DateUtil.now();
+        MidnightTime.calc(now);
+        Assert.assertEquals(MidnightTime.log(), "Hits: 0 misses: 1 stored: 0");
+    }
+}