From d4f372f5d45121b4dc70c721fcee7ef053d99e36 Mon Sep 17 00:00:00 2001
From: Andrew Scott <ascott18@gmail.com>
Date: Thu, 28 Sep 2023 15:32:21 -0700
Subject: [PATCH] fix: TimeOnly and DateOnly responses from the server not
 parsed correctly.

---
 src/coalesce-vue/src/model.ts               |  2 +-
 src/coalesce-vue/src/util.ts                | 40 ++++++++++++++++++---
 src/coalesce-vue/test/model.toModel.spec.ts | 17 +++++++++
 3 files changed, 54 insertions(+), 5 deletions(-)

diff --git a/src/coalesce-vue/src/model.ts b/src/coalesce-vue/src/model.ts
index 217ee3e87..731ef8a54 100644
--- a/src/coalesce-vue/src/model.ts
+++ b/src/coalesce-vue/src/model.ts
@@ -201,7 +201,7 @@ export function parseValue(
       if (value instanceof Date) {
         date = value;
       } else if (type === "string") {
-        date = parseJSONDate(value);
+        date = parseJSONDate(value, meta.dateKind);
       }
 
       // isNaN is what date-fn's `isValid` calls internally,
diff --git a/src/coalesce-vue/src/util.ts b/src/coalesce-vue/src/util.ts
index 050a7fc3e..50d816097 100644
--- a/src/coalesce-vue/src/util.ts
+++ b/src/coalesce-vue/src/util.ts
@@ -44,8 +44,10 @@ export function isNullOrWhitespace(value: string | null | undefined) {
 }
 
 const iso8601DateRegex =
-  /^(\d{4})-(\d{2})-(\d{2})[T ](\d{2}):(\d{2}):(\d{2})(?:\.(\d{0,7}))?(?:Z|(.)(\d{2}):?(\d{2})?)?/;
-export function parseJSONDate(argument: string) {
+  /^(\d{4})-(\d{2})-(\d{2})(?:[T ](\d{2}):(\d{2}):(\d{2})(?:\.(\d{0,7}))?(?:Z|(.)(\d{2}):?(\d{2})?)?)?/;
+const iso8601TimeRegex =
+  /^(\d{2}):(\d{2}):(\d{2})(?:\.(\d{0,7}))?(?:Z|(.)(\d{2}):?(\d{2})?)?$/;
+export function parseJSONDate(argument: string, kind: DateKind = "datetime") {
   // DO NOT USE `new Date()` here.
   // Safari incorrectly interprets times without a timezone offset
   // (i.e. DateTime objects in c#) as UTC instead of local time.
@@ -61,10 +63,36 @@ export function parseJSONDate(argument: string) {
   // This method is only slightly slower than parseJSON,
   // but is still 3-4x faster than parseISO while also having much, much less code.
 
+  if (kind == "time") {
+    // Time-only formats might come from the server as truly only a time (C# TimeOnly type).
+    // "ISO 8601: Time without UTC offset information" https://github.com/dotnet/runtime/issues/53539
+
+    var timeParts = argument.match(iso8601TimeRegex) || [];
+    if (timeParts.length >= 3) {
+      // If ES Temporal was standardize we could maybe switch Coalesce to use it,
+      // but for now we just settle for using a Date and ignoring the time part.
+
+      // NOTE: We set the date to Jan 1 in to avoid Daylight Savings switch days,
+      // which if such a date were to be the date component of the `Date`, would fail
+      // to represent the time correctly.
+      return new Date(
+        new Date().getFullYear(),
+        0,
+        1,
+        +timeParts[1], // h
+        +timeParts[2], // m
+        +timeParts[3], // s
+        +((timeParts[4] || "0") + "00").substring(0, 3) // ms (maybe never used?)
+      );
+    }
+  }
+
   var parts = argument.match(iso8601DateRegex) || [];
 
-  const part9 = parts[9];
+  const part9 = parts[9]; // TZ offset
+
   if (part9 !== undefined) {
+    // Date+Time, with offset specifier
     return new Date(
       Date.UTC(
         +parts[1],
@@ -76,7 +104,8 @@ export function parseJSONDate(argument: string) {
         +((parts[7] || "0") + "00").substring(0, 3)
       )
     );
-  } else {
+  } else if (parts[4] !== undefined) {
+    // Date+Time, without offset specifier
     return new Date(
       +parts[1],
       +parts[2] - 1,
@@ -86,6 +115,9 @@ export function parseJSONDate(argument: string) {
       +parts[6],
       +((parts[7] || "0") + "00").substring(0, 3)
     );
+  } else {
+    // Date only, without a time portion:
+    return new Date(+parts[1], +parts[2] - 1, +parts[3]);
   }
 }
 
diff --git a/src/coalesce-vue/test/model.toModel.spec.ts b/src/coalesce-vue/test/model.toModel.spec.ts
index be9a56f50..ab9a0a8fd 100644
--- a/src/coalesce-vue/test/model.toModel.spec.ts
+++ b/src/coalesce-vue/test/model.toModel.spec.ts
@@ -81,6 +81,23 @@ const dtoToModelMappings = <MappingData[]>[
     dto: "2020-06-10T14:00:00",
     model: new Date(2020, 5, 10, 14, 0, 0, 0),
   },
+  {
+    meta: { ...studentProps.birthDate, dateKind: "date" },
+    dto: "2020-06-10",
+    model: new Date(2020, 5, 10, 0, 0, 0, 0),
+  },
+  {
+    meta: { ...studentProps.birthDate, dateKind: "time" },
+    dto: "12:34:56",
+    // Time-only parses as Jan 1 of current year to avoid un-representable times on DST changeover days.
+    model: new Date(new Date().getFullYear(), 0, 1, 12, 34, 56, 0),
+  },
+  {
+    // Time-only, represented in a datetime format.
+    meta: { ...studentProps.birthDate, dateKind: "time" },
+    dto: "2020-06-10T12:34:56",
+    model: new Date(2020, 5, 10, 12, 34, 56, 0),
+  },
   ...unparsable(
     studentProps.birthDate,
     "abc",