Bug 1840374 - Part 29: Sync AddDurationToOrSubtractDurationFromPlainY…

…earMonth. r=spidermonkey-reviewers,sfink

Implement the changes from <tc39/proposal-temporal#2484>.

Differential Revision: https://phabricator.services.mozilla.com/D182049

UltraBlame original commit: 2aff072a94c4b7ae26778e7308f853ab008bd8e2

js/src/builtin/temporal/PlainYearMonth.cpp

@@ -2966,6 +2966,106 @@ return
 false
 ;
 }
+Rooted
+<
+PlainObject
+*
+>
+fieldsCopy
+(
+cx
+CopyOptions
+(
+cx
+fields
+)
+)
+;
+if
+(
+!
+fieldsCopy
+)
+{
+return
+false
+;
+}
+Value
+one
+=
+Int32Value
+(
+1
+)
+;
+auto
+handleOne
+=
+Handle
+<
+Value
+>
+:
+:
+fromMarkedLocation
+(
+&
+one
+)
+;
+if
+(
+!
+DefineDataProperty
+(
+cx
+fields
+cx
+-
+>
+names
+(
+)
+.
+day
+handleOne
+)
+)
+{
+return
+false
+;
+}
+Rooted
+<
+Wrapped
+<
+PlainDateObject
+*
+>
+>
+intermediateDate
+(
+cx
+CalendarDateFromFields
+(
+cx
+calendar
+fields
+)
+)
+;
+if
+(
+!
+intermediateDate
+)
+{
+return
+false
+;
+}
 int32_t
 sign
 =
@@ -2991,7 +3091,69 @@ Rooted
 <
 Value
 >
-day
+dateAdd
+(
+cx
+)
+;
+if
+(
+calendar
+.
+isObject
+(
+)
+)
+{
+Rooted
+<
+JSObject
+*
+>
+calendarObj
+(
+cx
+calendar
+.
+toObject
+(
+)
+)
+;
+if
+(
+!
+GetMethod
+(
+cx
+calendarObj
+cx
+-
+>
+names
+(
+)
+.
+dateAdd
+&
+dateAdd
+)
+)
+{
+return
+false
+;
+}
+}
+Rooted
+<
+Wrapped
+<
+PlainDateObject
+*
+>
+>
+date
 (
 cx
 )
@@ -3003,46 +3165,125 @@ sign
 0
 )
 {
+Duration
+oneMonthDuration
+=
+{
+0
+1
+}
+;
 Rooted
 <
-Value
+Wrapped
+<
+PlainDateObject
+*
+>
 >
-yearMonthValue
+nextMonth
 (
 cx
-ObjectValue
+CalendarDateAdd
 (
-*
-yearMonth
+cx
+calendar
+intermediateDate
+oneMonthDuration
+dateAdd
 )
 )
 ;
 if
 (
 !
-CalendarDaysInMonth
+nextMonth
+)
+{
+return
+false
+;
+}
+Duration
+minusDayDuration
+=
+{
+0
+0
+0
+-
+1
+}
+;
+Rooted
+<
+Wrapped
+<
+PlainDateObject
+*
+>
+>
+endOfMonth
+(
+cx
+CalendarDateAdd
 (
 cx
 calendar
-yearMonthValue
-&
-day
+nextMonth
+minusDayDuration
+dateAdd
 )
 )
+;
+if
+(
+!
+endOfMonth
+)
 {
 return
 false
 ;
 }
-}
-else
-{
+Rooted
+<
+Value
+>
+endOfMonthValue
+(
+cx
+ObjectValue
+(
+*
+endOfMonth
+)
+)
+;
+Rooted
+<
+Value
+>
 day
-.
-setInt32
 (
-1
+cx
+)
+;
+if
+(
+!
+CalendarDay
+(
+cx
+calendar
+endOfMonthValue
+&
+day
+)
 )
+{
+return
+false
 ;
 }
 if
@@ -3051,7 +3292,7 @@ if
 DefineDataProperty
 (
 cx
-fields
+fieldsCopy
 cx
 -
 >
@@ -3068,23 +3309,13 @@ return
 false
 ;
 }
-Rooted
-<
-Wrapped
-<
-PlainDateObject
-*
->
->
 date
-(
-cx
+=
 CalendarDateFromFields
 (
 cx
 calendar
-fields
-)
+fieldsCopy
 )
 ;
 if
@@ -3097,6 +3328,14 @@ return
 false
 ;
 }
+}
+else
+{
+date
+=
+intermediateDate
+;
+}
 Rooted
 <
 DurationObject
@@ -3178,6 +3417,7 @@ calendar
 date
 durationToAdd
 options
+dateAdd
 )
 )
 ;