improve date time helper

engine-tests/src/test/java/org/terasology/utilities/time/DateTimeHelperTest.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright 2018 MovingBlocks
+ *
+ * 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 org.terasology.utilities.time;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.Arrays;
+
+public class DateTimeHelperTest {
+
+    @Test
+    public void testGetDeltaBetweenTimestamps() {
+        Assert.assertEquals("00h 00m 01s", DateTimeHelper.getDeltaBetweenTimestamps(0, 1000));
+        Assert.assertEquals("00h 00m 10s", DateTimeHelper.getDeltaBetweenTimestamps(0, 10 * 1000));
+        Assert.assertEquals("00h 01m 00s", DateTimeHelper.getDeltaBetweenTimestamps(0, 60 * 1000));
+        Assert.assertEquals("00h 11m 00s", DateTimeHelper.getDeltaBetweenTimestamps(0, 60 * 1000 * 11));
+        Assert.assertEquals("01h 00m 00s", DateTimeHelper.getDeltaBetweenTimestamps(0, 60 * 1000 * 60));
+        Assert.assertEquals("12h 34m 56s", DateTimeHelper.getDeltaBetweenTimestamps(0, 60 * 1000 * 60 * 12 + 60 * 1000 * 34 + 56 * 1000));
+
+        Assert.assertEquals("1 Days 01h 00m 00s", DateTimeHelper.getDeltaBetweenTimestamps(0, 60 * 1000 * 60 * 25));
+        Assert.assertEquals("1 Days 01h 20m 40s", DateTimeHelper.getDeltaBetweenTimestamps(0, 60 * 1000 * 60 * 24 + 60 * 1000 * 60 + 60 * 1000 * 20 + 40 * 1000));
+
+        Assert.assertEquals("00h 00m 00s", DateTimeHelper.getDeltaBetweenTimestamps(1000, 1000));
+        Assert.assertEquals("00h 00m 00s", DateTimeHelper.getDeltaBetweenTimestamps(50000, 50000));
+
+        Assert.assertEquals("11h 01m 01s", DateTimeHelper.getDeltaBetweenTimestamps(1000 * 60 * 25, 1000 * 60 * 25 + 60 * 1000 * 60 * 11 + 60 * 1000 + 1000));
+    }
+
+    @Test
+    public void testGetDeltaBetweenTimestampsWrongData() {
+
+        Integer[][] wrongData = {
+                {-1, 50000},
+                {123, -1000},
+                {-667, -1000},
+                {123, 0},
+                {12321321, 1231}
+        };
+
+        Arrays.stream(wrongData).forEach(
+                data -> {
+                    try {
+                        DateTimeHelper.getDeltaBetweenTimestamps(data[0], data[1]);
+                        Assert.fail("Exception should be thrown!");
+                    } catch (IllegalArgumentException ex) {
+                        Assert.assertEquals("Wrong timestamp values: " + data[0] + " or " + data[1], ex.getMessage());
+                    }
+                }
+        );
+    }
+
+}

engine/src/main/java/org/terasology/utilities/time/DateTimeHelper.java

@@ -33,6 +33,9 @@ private DateTimeHelper() {
      * @return delta between timestamps as a string
      */
     public static String getDeltaBetweenTimestamps(final long start, final long end) {
+        if (start < 0 || end < 0 || start > end) {
+            throw new IllegalArgumentException("Wrong timestamp values: " + start + " or " + end);
+        }
         TimeUnit timeUnit = TimeUnit.SECONDS;
 
         long diffInMilliseconds = end - start;
@@ -49,7 +52,7 @@ public static String getDeltaBetweenTimestamps(final long start, final long end)
 
         if (days > 0) {
             builder.append(days);
-            builder.append(" Days");
+            builder.append(" Days ");
         }
 
         builder.append(fill2(hrs));