Add LocalDate and LocalDateTime constructors with Month

Author: ilya-g

core/commonMain/src/LocalDate.kt

@@ -37,6 +37,20 @@ public expect class LocalDate : Comparable<LocalDate> {
      */
     public constructor(year: Int, monthNumber: Int, dayOfMonth: Int)
 
+    /**
+     * Constructs a [LocalDate] instance from the given date components.
+     *
+     * The supported ranges of components:
+     * - [year] the range is platform dependent, but at least is enough to represent dates of all instants between
+     *          [Instant.DISTANT_PAST] and [Instant.DISTANT_FUTURE]
+     * - [month] all values of the [Month] enum
+     * - [dayOfMonth] `1..31`, the upper bound can be less, depending on the month
+     *
+     * @throws IllegalArgumentException if any parameter is out of range, or if [dayOfMonth] is invalid for the given [month] and
+     * [year].
+     */
+    public constructor(year: Int, month: Month, dayOfMonth: Int)
+
     /** Returns the year component of the date. */
     public val year: Int
     /** Returns the number-of-month (1..12) component of the date. */

core/commonMain/src/LocalDateTime.kt

@@ -49,6 +49,24 @@ public expect class LocalDateTime : Comparable<LocalDateTime> {
      */
     public constructor(year: Int, monthNumber: Int, dayOfMonth: Int, hour: Int, minute: Int, second: Int = 0, nanosecond: Int = 0)
 
+    /**
+     * Constructs a [LocalDateTime] instance from the given date and time components.
+     *
+     * The supported ranges of components:
+     * - [year] the range is platform dependent, but at least is enough to represent dates of all instants between
+     *          [Instant.DISTANT_PAST] and [Instant.DISTANT_FUTURE]
+     * - [month] all values of the [Month] enum
+     * - [dayOfMonth] `1..31`, the upper bound can be less, depending on the month
+     * - [hour] `0..23`
+     * - [minute] `0..59`
+     * - [second] `0..59`
+     * - [nanosecond] `0..999_999_999`
+     *
+     * @throws IllegalArgumentException if any parameter is out of range, or if [dayOfMonth] is invalid for the given [month] and
+     * [year].
+     */
+    public constructor(year: Int, month: Month, dayOfMonth: Int, hour: Int, minute: Int, second: Int = 0, nanosecond: Int = 0)
+
     /** Returns the year component of the date. */
     public val year: Int
     /** Returns the number-of-month (1..12) component of the date. */

core/commonTest/src/InstantTest.kt

@@ -103,7 +103,7 @@ class InstantTest {
             }
         }
 
-        val instant1 = LocalDateTime(2019, 10, 27, 2, 59).toInstant(zone)
+        val instant1 = LocalDateTime(2019, Month.OCTOBER, 27, 2, 59).toInstant(zone)
         checkComponents(instant1.toLocalDateTime(zone), 2019, 10, 27, 2, 59)
 
         val instant2 = instant1.plus(DateTimePeriod(hours = 24), zone)
@@ -232,9 +232,8 @@ class InstantTest {
             with(TimeZone.UTC) TZ@ {
                 val date1 = Instant.fromEpochMilliseconds(millis1).toLocalDateTime().date
                 val date2 = Instant.fromEpochMilliseconds(millis2).toLocalDateTime().date
-                fun LocalDate.instantAtStartOfDay() = LocalDateTime(year, monthNumber, dayOfMonth, 0, 0, 0, 0).toInstant()
-                val instant1 = date1.instantAtStartOfDay()
-                val instant2 = date2.instantAtStartOfDay()
+                val instant1 = date1.atStartOfDayIn(this@TZ)
+                val instant2 = date2.atStartOfDayIn(this@TZ)
 
                 val diff1 = instant1.periodUntil(instant2, this@TZ)
                 val diff2 = date1.periodUntil(date2)

core/commonTest/src/LocalDateTest.kt

@@ -54,13 +54,13 @@ class LocalDateTest {
     @Test
     fun localDateTimePart() {
         val datetime = LocalDateTime.parse("2016-02-29T23:59")
-        val date = LocalDate(2016, 2, 29)
+        val date = LocalDate(2016, Month.FEBRUARY, 29)
         checkLocalDateTimePart(date, datetime)
     }
 
     @Test
     fun atTime() {
-        val date = LocalDate(2016, 2, 29)
+        val date = LocalDate(2016, Month.FEBRUARY, 29)
         val datetime = date.atTime(12, 1, 59)
         checkComponents(datetime, 2016, 2, 29, 12, 1, 59)
         checkLocalDateTimePart(date, datetime)
@@ -231,4 +231,4 @@ fun checkInvalidDate(constructor: (year: Int, month: Int, day: Int) -> LocalDate
     assertFailsWith<IllegalArgumentException> { constructor(2007, 1, 32) }
     assertFailsWith<IllegalArgumentException> { constructor(2007, 0, 1) }
     assertFailsWith<IllegalArgumentException> { constructor(2007, 13, 1) }
-}
+}

core/commonTest/src/LocalDateTimeTest.kt

@@ -106,7 +106,7 @@ class LocalDateTimeTest {
     @Test
     fun constructInvalidTime() {
         fun localTime(hour: Int, minute: Int, second: Int = 0, nanosecond: Int = 0): LocalDateTime =
-            LocalDateTime(2020, 1, 1, hour, minute, second, nanosecond)
+            LocalDateTime(2020, Month.JANUARY, 1, hour, minute, second, nanosecond)
         localTime(23, 59)
         assertFailsWith<IllegalArgumentException> { localTime(-1, 0) }
         assertFailsWith<IllegalArgumentException> { localTime(24, 0) }

core/jsMain/src/LocalDate.kt

@@ -29,6 +29,8 @@ public actual class LocalDate internal constructor(internal val value: jtLocalDa
                 throw e
             })
 
+    public actual constructor(year: Int, month: Month, dayOfMonth: Int) : this(year, month.number, dayOfMonth)
+
     public actual val year: Int get() = value.year().toInt()
     public actual val monthNumber: Int get() = value.monthValue().toInt()
     public actual val month: Month get() = value.month().toMonth()

core/jsMain/src/LocalDateTime.kt

@@ -17,6 +17,9 @@ public actual class LocalDateTime internal constructor(internal val value: jtLoc
                 throw e
             })
 
+    public actual constructor(year: Int, month: Month, dayOfMonth: Int, hour: Int, minute: Int, second: Int, nanosecond: Int) :
+            this(year, month.number, dayOfMonth, hour, minute, second, nanosecond)
+
     public actual val year: Int get() = value.year().toInt()
     public actual val monthNumber: Int get() = value.monthValue().toInt()
     public actual val month: Month get() = value.month().toMonth()

core/jvmMain/src/LocalDate.kt

@@ -30,6 +30,8 @@ public actual class LocalDate internal constructor(internal val value: jtLocalDa
                 throw IllegalArgumentException(e)
             })
 
+    public actual constructor(year: Int, month: Month, dayOfMonth: Int) : this(year, month.number, dayOfMonth)
+
     public actual val year: Int get() = value.year
     public actual val monthNumber: Int get() = value.monthValue
     public actual val month: Month get() = value.month

core/jvmMain/src/LocalDateTime.kt

@@ -22,6 +22,9 @@ public actual class LocalDateTime internal constructor(internal val value: jtLoc
                 throw IllegalArgumentException(e)
             })
 
+    public actual constructor(year: Int, month: Month, dayOfMonth: Int, hour: Int, minute: Int, second: Int, nanosecond: Int) :
+            this(year, month.number, dayOfMonth, hour, minute, second, nanosecond)
+
     public actual val year: Int get() = value.year
     public actual val monthNumber: Int get() = value.monthValue
     public actual val month: Month get() = value.month

core/nativeMain/src/LocalDate.kt

@@ -50,6 +50,8 @@ public actual class LocalDate actual constructor(actual val year: Int, actual va
         }
     }
 
+    public actual constructor(year: Int, month: Month, dayOfMonth: Int) : this(year, month.number, dayOfMonth)
+
     actual companion object {
         actual fun parse(isoString: String): LocalDate =
             localDateParser.parse(isoString)