From 1aca001faa1b6325fb9c8e5493bedcf7afb43661 Mon Sep 17 00:00:00 2001
From: Davi de Castro Reis <davi.reis@gmail.com>
Date: Sat, 3 Sep 2022 21:13:15 -0300
Subject: [PATCH] Differ explicit epoch from null in timestamp conversion.

---
 .../common/ProtobufStandardMappings.java          | 12 ++++++++----
 .../no/entur/abt/mapstruct/common/Timestamps.java |  3 ---
 .../mapstruct/ProtobufStandardMappingsTest.java   | 15 +++++++++++++--
 .../mapstruct/ProtobufStandardMappingsTest.java   | 15 +++++++++++++--
 4 files changed, 34 insertions(+), 11 deletions(-)

diff --git a/support-core/src/main/java/no/entur/abt/mapstruct/common/ProtobufStandardMappings.java b/support-core/src/main/java/no/entur/abt/mapstruct/common/ProtobufStandardMappings.java
index a53292c..72ea79c 100644
--- a/support-core/src/main/java/no/entur/abt/mapstruct/common/ProtobufStandardMappings.java
+++ b/support-core/src/main/java/no/entur/abt/mapstruct/common/ProtobufStandardMappings.java
@@ -141,6 +141,10 @@ default ByteString map(BytesValue f) {
     }
 
     default Instant mapToInstant(Timestamp t) {
+        if (t == null) {
+            return null;
+        }
+
         Timestamp sanitized = Timestamps.sanitize(t);
 
         if (sanitized != null) {
@@ -151,11 +155,11 @@ default Instant mapToInstant(Timestamp t) {
     }
 
     default Timestamp mapToTimestamp(Instant i) {
-        if (i == null || i.getEpochSecond() == 0) {
+        if (i == null) {
             return null;
-        } else {
-            Timestamp t = Timestamp.newBuilder().setSeconds(i.getEpochSecond()).setNanos(i.getNano()).build();
-            return Timestamps.sanitize(t);
         }
+
+        Timestamp t = Timestamp.newBuilder().setSeconds(i.getEpochSecond()).setNanos(i.getNano()).build();
+        return Timestamps.sanitize(t);
     }
 }
diff --git a/support-core/src/main/java/no/entur/abt/mapstruct/common/Timestamps.java b/support-core/src/main/java/no/entur/abt/mapstruct/common/Timestamps.java
index cc66e2f..e5681bd 100644
--- a/support-core/src/main/java/no/entur/abt/mapstruct/common/Timestamps.java
+++ b/support-core/src/main/java/no/entur/abt/mapstruct/common/Timestamps.java
@@ -46,9 +46,6 @@ public class Timestamps {
      * Sanitize Timestamps outside legal range where possible.
      */
     public static Timestamp sanitize(Timestamp t) {
-        if (t.getSeconds() == 0 && t.getNanos() == 0) {
-            return null; // Assuming null for epoch, cannot differentiate
-        }
         if (t.getNanos() < 0 || t.getNanos() >= NANOS_PER_SECOND) {
             throw new IllegalArgumentException(String.format("Timestamp is not valid. See proto definition for valid values. Seconds (%s) must be in range [-62,135,596,800, +253,402,300,799]. Nanos (%s) must be in range [0, +999,999,999].", t.getSeconds(), t.getNanos()));
         }
diff --git a/support-lite/src/test/java/no/entur/abt/mapstruct/ProtobufStandardMappingsTest.java b/support-lite/src/test/java/no/entur/abt/mapstruct/ProtobufStandardMappingsTest.java
index aa50d00..1ca7efa 100644
--- a/support-lite/src/test/java/no/entur/abt/mapstruct/ProtobufStandardMappingsTest.java
+++ b/support-lite/src/test/java/no/entur/abt/mapstruct/ProtobufStandardMappingsTest.java
@@ -67,8 +67,19 @@ public void testMapLocalDateToTimestampWintertime() {
 	}
 
 	@Test
-	public void mapToInstant_whenSecondsAndNanosIs0_thenMapToNull() {
-		assertNull(MAPPER.mapToInstant(Timestamp.newBuilder().build()));
+	public void testMapInstantToTimestampEpoch() {
+		Instant epoch = Instant.EPOCH;
+
+		Timestamp timestamp = MAPPER.mapToTimestamp(epoch);
+
+		Instant back = MAPPER.mapToInstant(timestamp);
+
+		assertEquals(epoch, back);
+	}
+
+	@Test
+	public void mapToInstant_whenSecondsAndNanosIsNull_thenMapToNull() {
+		assertNull(MAPPER.mapToInstant(null));
 	}
 
 	@Test
diff --git a/support-standard/src/test/java/no/entur/abt/mapstruct/ProtobufStandardMappingsTest.java b/support-standard/src/test/java/no/entur/abt/mapstruct/ProtobufStandardMappingsTest.java
index 172854a..5cc69e1 100644
--- a/support-standard/src/test/java/no/entur/abt/mapstruct/ProtobufStandardMappingsTest.java
+++ b/support-standard/src/test/java/no/entur/abt/mapstruct/ProtobufStandardMappingsTest.java
@@ -66,10 +66,21 @@ public void testMapLocalDateToTimestampWintertime() {
         assertEquals(l, back);
     }
 
+    @Test
+    public void testMapInstantToTimestampEpoch() {
+        Instant epoch = Instant.EPOCH;
+
+        Timestamp timestamp = MAPPER.mapToTimestamp(epoch);
+
+        Instant back = MAPPER.mapToInstant(timestamp);
+
+        assertEquals(epoch, back);
+    }
+
 
     @Test
-    public void mapToInstant_whenSecondsAndNanosIs0_thenMapToNull() {
-        assertNull(MAPPER.mapToInstant(Timestamp.newBuilder().build()));
+    public void mapToInstant_whenSecondsAndNanosIsNull_thenMapToNull() {
+        assertNull(MAPPER.mapToInstant(null));
     }
 
     @Test