From dced873b34d793ac6ffc76edee26d7a5b0d74f9f Mon Sep 17 00:00:00 2001
From: Vasiliy Sadokhin <vasiliy.sadokhin@gmail.com>
Date: Sun, 30 Sep 2018 19:56:48 +0800
Subject: [PATCH] Fixed the utility to put week date to previous (instead of
 next) Monday when current day is Sunday

---
 .../vsadokhin/iot/data/utility/DateUtility.java  |  3 ++-
 .../iot/data/utility/DateUtilityTest.java        | 16 +++++++++++++++-
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/data/src/main/java/me/vsadokhin/iot/data/utility/DateUtility.java b/data/src/main/java/me/vsadokhin/iot/data/utility/DateUtility.java
index 608919a..b7ce8fe 100644
--- a/data/src/main/java/me/vsadokhin/iot/data/utility/DateUtility.java
+++ b/data/src/main/java/me/vsadokhin/iot/data/utility/DateUtility.java
@@ -3,6 +3,7 @@
 import java.time.Instant;
 import java.time.temporal.ChronoUnit;
 import java.util.Calendar;
+import java.util.Locale;
 import java.util.TimeZone;
 
 public final class DateUtility {
@@ -14,7 +15,7 @@ public static long getDayStart(long milliseconds) {
     }
 
     public static long getWeekStart(long milliseconds) {
-        Calendar calendar = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
+        Calendar calendar = Calendar.getInstance(TimeZone.getTimeZone("UTC"), Locale.UK);
         calendar.setTimeInMillis(milliseconds);
         calendar.set(Calendar.MILLISECOND, 0);
         calendar.set(Calendar.SECOND, 0);
diff --git a/data/src/test/java/me/vsadokhin/iot/data/utility/DateUtilityTest.java b/data/src/test/java/me/vsadokhin/iot/data/utility/DateUtilityTest.java
index 0a6b233..a631d41 100644
--- a/data/src/test/java/me/vsadokhin/iot/data/utility/DateUtilityTest.java
+++ b/data/src/test/java/me/vsadokhin/iot/data/utility/DateUtilityTest.java
@@ -9,6 +9,7 @@
 import java.time.ZoneOffset;
 import java.time.ZonedDateTime;
 import java.util.Calendar;
+import java.util.Date;
 import java.util.TimeZone;
 
 import org.junit.Test;
@@ -34,7 +35,7 @@ public void getDayStart() {
     }
 
     @Test
-    public void getWeekStart() {
+    public void getWeekStart_checkResultIsMondayMidnight() {
         // setup
         Instant instant = LocalDate.of(2018, 9, 29).atStartOfDay().toInstant(ZoneOffset.UTC);
 
@@ -44,4 +45,17 @@ public void getWeekStart() {
         // verify
         assertThat(result, is(ZonedDateTime.of(2018,9,24,0,0,0,0,ZoneId.of("UTC")).toInstant().toEpochMilli()));
     }
+
+    @Test
+    public void getWeekStart_sundayCornerCase_checkWeekStartIsStillMondayMidnight() {
+        // setup
+        Instant instant = LocalDate.of(2018, 9, 30).atStartOfDay().toInstant(ZoneOffset.UTC);
+
+        // act
+        long result = DateUtility.getWeekStart(instant.toEpochMilli());
+
+        // verify
+        System.out.println(new Date(result));
+        assertThat(result, is(ZonedDateTime.of(2018,9,24,0,0,0,0,ZoneId.of("UTC")).toInstant().toEpochMilli()));
+    }
 }
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