From 3de4d56527f7160de1b1e05fba2f4dce2466c243 Mon Sep 17 00:00:00 2001
From: Mike Angstadt <mike.angstadt@gmail.com>
Date: Sun, 2 Feb 2025 09:02:24 -0500
Subject: [PATCH] Allow partial dates to be written to non-4.0 vCards for
 round-tripping

https://github.com/mangstadt/ez-vcard/issues/155
---
 .../io/scribe/DateOrTimePropertyScribe.java      | 16 ++++++++++------
 .../io/scribe/DateOrTimePropertyScribeTest.java  | 12 ++++++------
 2 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/src/main/java/ezvcard/io/scribe/DateOrTimePropertyScribe.java b/src/main/java/ezvcard/io/scribe/DateOrTimePropertyScribe.java
index 6a71ad3c..40aa3206 100644
--- a/src/main/java/ezvcard/io/scribe/DateOrTimePropertyScribe.java
+++ b/src/main/java/ezvcard/io/scribe/DateOrTimePropertyScribe.java
@@ -88,22 +88,24 @@ protected VCardDataType _dataType(T property, VCardVersion version) {
 	@Override
 	protected String _writeText(T property, WriteContext context) {
 		VCardVersion version = context.getVersion();
+		boolean extended = (version == VCardVersion.V3_0);
+
 		Temporal date = property.getDate();
 		if (date != null) {
-			boolean extended = (version == VCardVersion.V3_0);
 			return date(date).extended(extended).write();
 		}
 
+		//allow partial dates to be written to non-4.0 vCards for leniency and round-tripping
+		PartialDate partialDate = property.getPartialDate();
+		if (partialDate != null) {
+			return partialDate.toISO8601(extended);
+		}
+
 		if (version == VCardVersion.V4_0) {
 			String text = property.getText();
 			if (text != null) {
 				return VObjectPropertyValues.escape(text);
 			}
-
-			PartialDate partialDate = property.getPartialDate();
-			if (partialDate != null) {
-				return partialDate.toISO8601(false);
-			}
 		}
 
 		return "";
@@ -222,6 +224,8 @@ private T parse(String value, ParseContext context) {
 			return newInstance(date(value));
 		} catch (IllegalArgumentException e) {
 			try {
+				//allow partial dates to be parsed from non-4.0 vCards
+				//https://github.com/mangstadt/ez-vcard/issues/155
 				return newInstance(PartialDate.parse(value));
 			} catch (IllegalArgumentException e2) {
 				if (context.getVersion() == VCardVersion.V2_1 || context.getVersion() == VCardVersion.V3_0) {
diff --git a/src/test/java/ezvcard/io/scribe/DateOrTimePropertyScribeTest.java b/src/test/java/ezvcard/io/scribe/DateOrTimePropertyScribeTest.java
index b03726ac..ad259a3d 100644
--- a/src/test/java/ezvcard/io/scribe/DateOrTimePropertyScribeTest.java
+++ b/src/test/java/ezvcard/io/scribe/DateOrTimePropertyScribeTest.java
@@ -124,12 +124,12 @@ public void writeText() {
 		sensei.assertWriteText(withDate).versions(V3_0).run(dateExtendedStr);
 		sensei.assertWriteText(withDateTime).versions(V2_1, V4_0).run(dateTimeStr);
 		sensei.assertWriteText(withDateTime).versions(V3_0).run(dateTimeExtendedStr);
-		sensei.assertWriteText(withPartialDate).versions(V2_1, V3_0).run("");
-		sensei.assertWriteText(withPartialDate).versions(V4_0).run(partialDate.toISO8601(false));
-		sensei.assertWriteText(withPartialTime).versions(V2_1, V3_0).run("");
-		sensei.assertWriteText(withPartialTime).versions(V4_0).run(partialTime.toISO8601(false));
-		sensei.assertWriteText(withPartialDateTime).versions(V2_1, V3_0).run("");
-		sensei.assertWriteText(withPartialDateTime).versions(V4_0).run(partialDateTime.toISO8601(false));
+		sensei.assertWriteText(withPartialDate).versions(V2_1, V4_0).run(partialDate.toISO8601(false));
+		sensei.assertWriteText(withPartialDate).versions(V3_0).run(partialDate.toISO8601(true));
+		sensei.assertWriteText(withPartialTime).versions(V2_1, V4_0).run(partialTime.toISO8601(false));
+		sensei.assertWriteText(withPartialTime).versions(V3_0).run(partialTime.toISO8601(true));
+		sensei.assertWriteText(withPartialDateTime).versions(V2_1, V4_0).run(partialDateTime.toISO8601(false));
+		sensei.assertWriteText(withPartialDateTime).versions(V3_0).run(partialDateTime.toISO8601(true));
 		sensei.assertWriteText(withText).versions(V2_1, V3_0).run("");
 		sensei.assertWriteText(withText).versions(V4_0).run(textEscaped);
 		sensei.assertWriteText(empty).run("");