Implement LocalDate.fromEpochDays

core/build.gradle.kts

@@ -68,7 +68,7 @@ kotlin {
         nodejs {
             testTask {
                 useMocha {
-                    timeout = "5s"
+                    timeout = "30s"
                 }
             }
         }

core/common/src/DateTimePeriod.kt

@@ -5,6 +5,7 @@
 
 package kotlinx.datetime
 
+import kotlinx.datetime.internal.*
 import kotlinx.datetime.serializers.DatePeriodIso8601Serializer
 import kotlinx.datetime.serializers.DateTimePeriodIso8601Serializer
 import kotlin.math.*

core/common/src/DateTimeUnit.kt

@@ -5,6 +5,7 @@
 
 package kotlinx.datetime
 
+import kotlinx.datetime.internal.safeMultiply
 import kotlinx.datetime.serializers.*
 import kotlinx.serialization.Serializable
 import kotlin.time.*

core/common/src/Instant.kt

@@ -5,6 +5,7 @@
 
 package kotlinx.datetime
 
+import kotlinx.datetime.internal.*
 import kotlinx.datetime.serializers.InstantIso8601Serializer
 import kotlinx.serialization.Serializable
 import kotlin.time.*
@@ -126,6 +127,8 @@ public expect class Instant : Comparable<Instant> {
          * Returns an [Instant] that is [epochMilliseconds] number of milliseconds from the epoch instant `1970-01-01T00:00:00Z`.
          *
          * The return value is clamped to the platform-specific boundaries for [Instant] if the result exceeds them.
+         *
+         * @see Instant.toEpochMilliseconds
          */
         public fun fromEpochMilliseconds(epochMilliseconds: Long): Instant
 

core/common/src/LocalDate.kt

@@ -32,6 +32,15 @@ public expect class LocalDate : Comparable<LocalDate> {
          */
         public fun parse(isoString: String): LocalDate
 
+        /**
+         * Returns a [LocalDate] that is [epochDays] number of days from the epoch day `1970-01-01`.
+         *
+         * @throws IllegalArgumentException if the result exceeds the platform-specific boundaries of [LocalDate].
+         *
+         * @see LocalDate.toEpochDays
+         */
+        public fun fromEpochDays(epochDays: Int): LocalDate
+
         internal val MIN: LocalDate
         internal val MAX: LocalDate
     }
@@ -79,6 +88,15 @@ public expect class LocalDate : Comparable<LocalDate> {
     /** Returns the day-of-year component of the date. */
     public val dayOfYear: Int
 
+    /**
+     * Returns the number of days since the epoch day `1970-01-01`.
+     *
+     * If the result does not fit in [Int], returns [Int.MAX_VALUE] for a positive result or [Int.MIN_VALUE] for a negative result.
+     *
+     * @see LocalDate.fromEpochDays
+     */
+    public fun toEpochDays(): Int
+
     /**
      * Compares `this` date with the [other] date.
      * Returns zero if this date represent the same day as the other (i.e. equal to other),

core/common/src/internal/dateCalculations.kt

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2019-2022 JetBrains s.r.o. and contributors.
+ * Use of this source code is governed by the Apache 2.0 License that can be found in the LICENSE.txt file.
+ */
+
+package kotlinx.datetime.internal
+
+internal const val SECONDS_PER_HOUR = 60 * 60
+
+internal const val SECONDS_PER_MINUTE = 60
+
+internal const val MINUTES_PER_HOUR = 60
+
+internal const val HOURS_PER_DAY = 24
+
+internal const val SECONDS_PER_DAY: Int = SECONDS_PER_HOUR * HOURS_PER_DAY
+
+internal const val NANOS_PER_ONE = 1_000_000_000
+internal const val NANOS_PER_MILLI = 1_000_000
+internal const val MILLIS_PER_ONE = 1_000
+
+internal const val NANOS_PER_DAY: Long = NANOS_PER_ONE * SECONDS_PER_DAY.toLong()
+
+internal const val NANOS_PER_MINUTE: Long = NANOS_PER_ONE * SECONDS_PER_MINUTE.toLong()
+
+internal const val NANOS_PER_HOUR = NANOS_PER_ONE * SECONDS_PER_HOUR.toLong()
+
+internal const val MILLIS_PER_DAY: Int = SECONDS_PER_DAY * MILLIS_PER_ONE
+
+// org.threeten.bp.chrono.IsoChronology#isLeapYear
+internal fun isLeapYear(year: Int): Boolean {
+    val prolepticYear: Long = year.toLong()
+    return prolepticYear and 3 == 0L && (prolepticYear % 100 != 0L || prolepticYear % 400 == 0L)
+}
+
+internal fun Int.monthLength(isLeapYear: Boolean): Int =
+    when (this) {
+        2 -> if (isLeapYear) 29 else 28
+        4, 6, 9, 11 -> 30
+        else -> 31
+    }

core/common/src/math.kt → core/common/src/internal/math.kt

@@ -3,7 +3,7 @@
  * Use of this source code is governed by the Apache 2.0 License that can be found in the LICENSE.txt file.
  */
 
-package kotlinx.datetime
+package kotlinx.datetime.internal
 
 internal fun Long.clampToInt(): Int =
         when {
@@ -12,28 +12,6 @@ internal fun Long.clampToInt(): Int =
             else -> toInt()
         }
 
-internal const val SECONDS_PER_HOUR = 60 * 60
-
-internal const val SECONDS_PER_MINUTE = 60
-
-internal const val MINUTES_PER_HOUR = 60
-
-internal const val HOURS_PER_DAY = 24
-
-internal const val SECONDS_PER_DAY: Int = SECONDS_PER_HOUR * HOURS_PER_DAY
-
-internal const val NANOS_PER_ONE = 1_000_000_000
-internal const val NANOS_PER_MILLI = 1_000_000
-internal const val MILLIS_PER_ONE = 1_000
-
-internal const val NANOS_PER_DAY: Long = NANOS_PER_ONE * SECONDS_PER_DAY.toLong()
-
-internal const val NANOS_PER_MINUTE: Long = NANOS_PER_ONE * SECONDS_PER_MINUTE.toLong()
-
-internal const val NANOS_PER_HOUR = NANOS_PER_ONE * SECONDS_PER_HOUR.toLong()
-
-internal const val MILLIS_PER_DAY: Int = SECONDS_PER_DAY * MILLIS_PER_ONE
-
 internal expect fun safeMultiply(a: Long, b: Long): Long
 internal expect fun safeMultiply(a: Int, b: Int): Int
 internal expect fun safeAdd(a: Long, b: Long): Long
@@ -200,4 +178,4 @@ internal fun multiplyAndAdd(d: Long, n: Long, r: Long): Long {
         mr -= n
     }
     return safeAdd(safeMultiply(md, n), mr)
-}
+}

core/common/test/InstantTest.kt

@@ -7,6 +7,7 @@ package kotlinx.datetime.test
 
 import kotlinx.datetime.*
 import kotlinx.datetime.Clock // currently, requires an explicit import due to a conflict with the deprecated Clock from kotlin.time
+import kotlinx.datetime.internal.*
 import kotlin.random.*
 import kotlin.test.*
 import kotlin.time.*

core/common/test/LocalDateTest.kt

@@ -6,6 +6,7 @@
 package kotlinx.datetime.test
 
 import kotlinx.datetime.*
+import kotlinx.datetime.internal.*
 import kotlin.random.*
 import kotlin.test.*
 
@@ -36,8 +37,9 @@ class LocalDateTest {
 
     @Test
     fun parseIsoString() {
-        fun checkParsedComponents(value: String, year: Int, month: Int, day: Int, dayOfWeek: Int, dayOfYear: Int) {
+        fun checkParsedComponents(value: String, year: Int, month: Int, day: Int, dayOfWeek: Int? = null, dayOfYear: Int? = null) {
             checkComponents(LocalDate.parse(value), year, month, day, dayOfWeek, dayOfYear)
+            assertEquals(value, LocalDate(year, month, day).toString())
         }
         checkParsedComponents("2019-10-01", 2019, 10, 1, 2, 274)
         checkParsedComponents("2016-02-29", 2016, 2, 29, 1, 60)
@@ -49,6 +51,17 @@ class LocalDateTest {
         assertInvalidFormat { LocalDate.parse("2017-10--01") }
         // this date is currently larger than the largest representable one any of the platforms:
         assertInvalidFormat { LocalDate.parse("+1000000000-10-01") }
+        // threetenbp
+        checkParsedComponents("2008-07-05", 2008, 7, 5)
+        checkParsedComponents("2007-12-31", 2007, 12, 31)
+        checkParsedComponents("0999-12-31", 999, 12, 31)
+        checkParsedComponents("-0001-01-02", -1, 1, 2)
+        checkParsedComponents("9999-12-31", 9999, 12, 31)
+        checkParsedComponents("-9999-12-31", -9999, 12, 31)
+        checkParsedComponents("+10000-01-01", 10000, 1, 1)
+        checkParsedComponents("-10000-01-01", -10000, 1, 1)
+        checkParsedComponents("+123456-01-01", 123456, 1, 1)
+        checkParsedComponents("-123456-01-01", -123456, 1, 1)
     }
 
     @Test
@@ -221,9 +234,61 @@ class LocalDateTest {
             assertEquals(Int.MIN_VALUE, LocalDate.MAX.until(LocalDate.MIN, DateTimeUnit.DAY))
         }
     }
-}
-
+    @Test
+    fun fromEpochDays() {
+        /** This test uses [LocalDate.next] and [LocalDate.previous] and not [LocalDate.plus] because, on Native,
+         * [LocalDate.plus] is implemented via [LocalDate.toEpochDays]/[LocalDate.fromEpochDays], and so it's better to
+         * test those independently. */
+        if (LocalDate.fromEpochDays(0).daysUntil(LocalDate.MIN) > Int.MIN_VALUE) {
+            assertEquals(LocalDate.MIN, LocalDate.fromEpochDays(LocalDate.MIN.toEpochDays()))
+            assertFailsWith<IllegalArgumentException> { LocalDate.fromEpochDays(LocalDate.MIN.toEpochDays() - 1) }
+            assertFailsWith<IllegalArgumentException> { LocalDate.fromEpochDays(Int.MIN_VALUE) }
+        }
+        if (LocalDate.fromEpochDays(0).daysUntil(LocalDate.MAX) < Int.MAX_VALUE) {
+            assertEquals(LocalDate.MAX, LocalDate.fromEpochDays(LocalDate.MAX.toEpochDays()))
+            assertFailsWith<IllegalArgumentException> { LocalDate.fromEpochDays(LocalDate.MAX.toEpochDays() + 1) }
+            assertFailsWith<IllegalArgumentException> { LocalDate.fromEpochDays(Int.MAX_VALUE) }
+        }
+        val eraBeginning = -678941 - 40587
+        assertEquals(LocalDate(1970, 1, 1), LocalDate.fromEpochDays(0))
+        assertEquals(LocalDate(0, 1, 1), LocalDate.fromEpochDays(eraBeginning))
+        assertEquals(LocalDate(-1, 12, 31), LocalDate.fromEpochDays(eraBeginning - 1))
+        var test = LocalDate(0, 1, 1)
+        for (i in eraBeginning..699999) {
+            assertEquals(test, LocalDate.fromEpochDays(i))
+            test = test.next
+        }
+        test = LocalDate(0, 1, 1)
+        for (i in eraBeginning downTo -2000000 + 1) {
+            assertEquals(test, LocalDate.fromEpochDays(i))
+            test = test.previous
+        }
+    }
 
+    // threetenbp
+    @Test
+    fun toEpochDays() {
+        /** This test uses [LocalDate.next] and [LocalDate.previous] and not [LocalDate.plus] because, on Native,
+         * [LocalDate.plus] is implemented via [LocalDate.toEpochDays]/[LocalDate.fromEpochDays], and so it's better to
+         * test those independently. */
+        val startOfEra = -678941 - 40587
+        var date = LocalDate(0, 1, 1)
+        for (i in startOfEra..699999) {
+            assertEquals(i, date.toEpochDays())
+            date = date.next
+        }
+        date = LocalDate(0, 1, 1)
+        for (i in startOfEra downTo -2000000 + 1) {
+            assertEquals(i, date.toEpochDays())
+            date = date.previous
+        }
+        assertEquals(-40587, LocalDate(1858, 11, 17).toEpochDays())
+        assertEquals(-678575 - 40587, LocalDate(1, 1, 1).toEpochDays())
+        assertEquals(49987 - 40587, LocalDate(1995, 9, 27).toEpochDays())
+        assertEquals(0, LocalDate(1970, 1, 1).toEpochDays())
+        assertEquals(-678942 - 40587, LocalDate(-1, 12, 31).toEpochDays())
+    }
+}
 
 fun checkInvalidDate(constructor: (year: Int, month: Int, day: Int) -> LocalDate) {
     assertFailsWith<IllegalArgumentException> { constructor(2007, 2, 29) }
@@ -236,3 +301,22 @@ fun checkInvalidDate(constructor: (year: Int, month: Int, day: Int) -> LocalDate
     assertFailsWith<IllegalArgumentException> { constructor(2007, 0, 1) }
     assertFailsWith<IllegalArgumentException> { constructor(2007, 13, 1) }
 }
+
+private val LocalDate.next: LocalDate get() =
+    if (dayOfMonth != monthNumber.monthLength(isLeapYear(year))) {
+        LocalDate(year, monthNumber, dayOfMonth + 1)
+    } else if (monthNumber != 12) {
+        LocalDate(year, monthNumber + 1, 1)
+    } else {
+        LocalDate(year + 1, 1, 1)
+    }
+
+private val LocalDate.previous: LocalDate get() =
+    if (dayOfMonth != 1) {
+        LocalDate(year, monthNumber, dayOfMonth - 1)
+    } else if (monthNumber != 1) {
+        val newMonthNumber = monthNumber - 1
+        LocalDate(year, newMonthNumber, newMonthNumber.monthLength(isLeapYear(year)))
+    } else {
+        LocalDate(year - 1, 12, 31)
+    }

core/common/test/LocalTimeTest.kt

@@ -6,6 +6,7 @@
 package kotlinx.datetime.test
 
 import kotlinx.datetime.*
+import kotlinx.datetime.internal.*
 import kotlin.math.*
 import kotlin.random.*
 import kotlin.test.*

core/common/test/MultiplyAndDivideTest.kt

@@ -6,7 +6,7 @@
 package kotlinx.datetime.test
 import kotlin.random.*
 import kotlin.test.*
-import kotlinx.datetime.*
+import kotlinx.datetime.internal.*
 
 class MultiplyAndDivideTest {
 

core/js/src/Instant.kt

@@ -11,6 +11,8 @@ import kotlinx.datetime.internal.JSJoda.OffsetDateTime as jtOffsetDateTime
 import kotlinx.datetime.internal.JSJoda.Duration as jtDuration
 import kotlinx.datetime.internal.JSJoda.Clock as jtClock
 import kotlinx.datetime.internal.JSJoda.ChronoUnit
+import kotlinx.datetime.internal.safeAdd
+import kotlinx.datetime.internal.*
 import kotlinx.datetime.serializers.InstantIso8601Serializer
 import kotlinx.serialization.Serializable
 import kotlin.time.*

core/js/src/LocalDate.kt

@@ -22,6 +22,13 @@ public actual class LocalDate internal constructor(internal val value: jtLocalDa
 
         internal actual val MIN: LocalDate = LocalDate(jtLocalDate.MIN)
         internal actual val MAX: LocalDate = LocalDate(jtLocalDate.MAX)
+
+        public actual fun fromEpochDays(epochDays: Int): LocalDate = try {
+            LocalDate(jtLocalDate.ofEpochDay(epochDays))
+        } catch (e: Throwable) {
+            if (e.isJodaDateTimeException()) throw IllegalArgumentException(e)
+            throw e
+        }
     }
 
     public actual constructor(year: Int, monthNumber: Int, dayOfMonth: Int) :
@@ -49,6 +56,8 @@ public actual class LocalDate internal constructor(internal val value: jtLocalDa
     actual override fun toString(): String = value.toString()
 
     actual override fun compareTo(other: LocalDate): Int = this.value.compareTo(other.value).toInt()
+
+    public actual fun toEpochDays(): Int = value.toEpochDay().toInt()
 }
 
 public actual fun LocalDate.plus(unit: DateTimeUnit.DateBased): LocalDate = plusNumber(1, unit)

core/js/src/LocalTime.kt

@@ -4,6 +4,7 @@
  */
 package kotlinx.datetime
 
+import kotlinx.datetime.internal.*
 import kotlinx.datetime.serializers.LocalTimeIso8601Serializer
 import kotlinx.serialization.Serializable
 import kotlinx.datetime.internal.JSJoda.LocalTime as jtLocalTime

core/js/src/mathJs.kt → core/js/src/internal/mathJs.kt

@@ -1,9 +1,9 @@
 /*
- * Copyright 2019-2020 JetBrains s.r.o.
+ * Copyright 2019-2022 JetBrains s.r.o. and contributors.
  * Use of this source code is governed by the Apache 2.0 License that can be found in the LICENSE.txt file.
  */
 
-package kotlinx.datetime
+package kotlinx.datetime.internal
 
 /**
  * Safely adds two long values.

core/jvm/src/Instant.kt

@@ -6,6 +6,8 @@
 
 package kotlinx.datetime
 
+import kotlinx.datetime.internal.safeMultiply
+import kotlinx.datetime.internal.*
 import kotlinx.datetime.serializers.InstantIso8601Serializer
 import kotlinx.serialization.Serializable
 import java.time.DateTimeException