Fixing LocalTime rounding (losing precision) (#1570)

* Fixing LocalTime rounding

* added tests for toLocalTime as well

pgjdbc/src/main/java/org/postgresql/jdbc/TimestampUtils.java

@@ -54,7 +54,7 @@ public class TimestampUtils {
   private static final Duration ONE_MICROSECOND = Duration.ofNanos(1000);
   // LocalTime.MAX is 23:59:59.999_999_999, and it wraps to 24:00:00 when nanos exceed 999_999_499
   // since PostgreSQL has microsecond resolution only
-  private static final LocalTime MAX_TIME = LocalTime.MAX.minus(Duration.ofMillis(500));
+  private static final LocalTime MAX_TIME = LocalTime.MAX.minus(Duration.ofNanos(500));
   private static final OffsetDateTime MAX_OFFSET_DATETIME = OffsetDateTime.MAX.minus(Duration.ofMillis(500));
   private static final LocalDateTime MAX_LOCAL_DATETIME = LocalDateTime.MAX.minus(Duration.ofMillis(500));
   // low value for dates is   4713 BC

pgjdbc/src/test/java/org/postgresql/jdbc/TimestampUtilsTest.java

@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2019, PostgreSQL Global Development Group
+ * See the LICENSE file in the project root for more information.
+ */
+
+package org.postgresql.jdbc;
+
+import static org.junit.Assert.assertEquals;
+
+import org.postgresql.core.Provider;
+
+import org.junit.Test;
+
+import java.sql.SQLException;
+//#if mvn.project.property.postgresql.jdbc.spec >= "JDBC4.2"
+import java.time.LocalTime;
+//#endif
+import java.util.TimeZone;
+
+public class TimestampUtilsTest {
+
+  //#if mvn.project.property.postgresql.jdbc.spec >= "JDBC4.2"
+  @Test
+  public void testToStringOfLocalTime() {
+    TimestampUtils timestampUtils = createTimestampUtils();
+
+    assertEquals("00:00:00", timestampUtils.toString(LocalTime.parse("00:00:00")));
+    assertEquals("00:00:00.1", timestampUtils.toString(LocalTime.parse("00:00:00.1")));
+    assertEquals("00:00:00.12", timestampUtils.toString(LocalTime.parse("00:00:00.12")));
+    assertEquals("00:00:00.123", timestampUtils.toString(LocalTime.parse("00:00:00.123")));
+    assertEquals("00:00:00.1234", timestampUtils.toString(LocalTime.parse("00:00:00.1234")));
+    assertEquals("00:00:00.12345", timestampUtils.toString(LocalTime.parse("00:00:00.12345")));
+    assertEquals("00:00:00.123456", timestampUtils.toString(LocalTime.parse("00:00:00.123456")));
+
+    assertEquals("00:00:00.999999", timestampUtils.toString(LocalTime.parse("00:00:00.999999")));
+    assertEquals("00:00:00.999999", timestampUtils.toString(LocalTime.parse("00:00:00.999999499"))); // 499 NanoSeconds
+    assertEquals("00:00:01", timestampUtils.toString(LocalTime.parse("00:00:00.999999500"))); // 500 NanoSeconds
+
+    assertEquals("23:59:59", timestampUtils.toString(LocalTime.parse("23:59:59")));
+    assertEquals("23:59:59.999999", timestampUtils.toString(LocalTime.parse("23:59:59.999999"))); // 0 NanoSeconds
+    assertEquals("23:59:59.999999", timestampUtils.toString(LocalTime.parse("23:59:59.999999499"))); // 499 NanoSeconds
+    assertEquals("24:00:00", timestampUtils.toString(LocalTime.parse("23:59:59.999999500")));// 500 NanoSeconds
+    assertEquals("24:00:00", timestampUtils.toString(LocalTime.parse("23:59:59.999999999")));// 999 NanoSeconds
+  }
+
+  @Test
+  public void testToLocalTime() throws SQLException {
+    TimestampUtils timestampUtils = createTimestampUtils();
+
+    assertEquals(LocalTime.parse("00:00:00"), timestampUtils.toLocalTime("00:00:00"));
+
+    assertEquals(LocalTime.parse("00:00:00.1"), timestampUtils.toLocalTime("00:00:00.1"));
+    assertEquals(LocalTime.parse("00:00:00.12"), timestampUtils.toLocalTime("00:00:00.12"));
+    assertEquals(LocalTime.parse("00:00:00.123"), timestampUtils.toLocalTime("00:00:00.123"));
+    assertEquals(LocalTime.parse("00:00:00.1234"), timestampUtils.toLocalTime("00:00:00.1234"));
+    assertEquals(LocalTime.parse("00:00:00.12345"), timestampUtils.toLocalTime("00:00:00.12345"));
+    assertEquals(LocalTime.parse("00:00:00.123456"), timestampUtils.toLocalTime("00:00:00.123456"));
+    assertEquals(LocalTime.parse("00:00:00.999999"), timestampUtils.toLocalTime("00:00:00.999999"));
+
+    assertEquals(LocalTime.parse("23:59:59"), timestampUtils.toLocalTime("23:59:59"));
+    assertEquals(LocalTime.parse("23:59:59.999999"), timestampUtils.toLocalTime("23:59:59.999999")); // 0 NanoSeconds
+    assertEquals(LocalTime.parse("23:59:59.9999999"), timestampUtils.toLocalTime("23:59:59.9999999")); // 900 NanoSeconds
+    assertEquals(LocalTime.parse("23:59:59.99999999"), timestampUtils.toLocalTime("23:59:59.99999999")); // 990 NanoSeconds
+    assertEquals(LocalTime.parse("23:59:59.999999998"), timestampUtils.toLocalTime("23:59:59.999999998")); // 998 NanoSeconds
+    assertEquals(LocalTime.parse("23:59:59.999999999"), timestampUtils.toLocalTime("24:00:00"));
+  }
+
+  private TimestampUtils createTimestampUtils() {
+    return  new TimestampUtils(true, new Provider<TimeZone>() {
+      @Override
+      public TimeZone get() {
+        return TimeZone.getDefault();
+      }
+    });
+  }
+  //#endif
+
+}