Merge pull request #128 from ionspin/127-fix-bigdecimal-division

Fix for #127
ionspin · Oct 8, 2020 · 7db6bcc · 7db6bcc
2 parents 0e4d9ae + eaba704
commit 7db6bcc
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,5 +1,11 @@
 ## Descriptive changelog
 (All dates are DD.MM.YYYY)
+##### 0.2.1 - 8.10.2020 - Fix infinite precision division, kotlin version bump
+- Fixed #127 BigDecimal divide not working properly
+- Added tests to cover case from #127
+- Bumped kotlin to 1.4.10
+- Bumped Dokka to 1.4.10, serialization to 1.0.0 
+
 ##### 0.2.0 - 18.8.2020 - Improvements, optimizations, bugfixes and Kotlin 1.4.0
 - Improvement #122 Add "scale" support to BigDecimal
 - Fixed #118 Rounding issue on division

diff --git a/bignum/build.gradle.kts b/bignum/build.gradle.kts
@@ -352,12 +352,6 @@ tasks {
 
     dokkaJavadoc {
         println("Dokka !")
-        dokkaSourceSets {
-            create("commonMain") {
-                displayName = "common"
-                platform = "common"
-            }
-        }
     }
     if (hostOsName == primaryDevelopmentOs) {
         val jvmTest by getting(Test::class) {

diff --git a/bignum/src/commonMain/kotlin/com/ionspin/kotlin/bignum/decimal/BigDecimal.kt b/bignum/src/commonMain/kotlin/com/ionspin/kotlin/bignum/decimal/BigDecimal.kt
@@ -89,7 +89,7 @@ class BigDecimal private constructor(
         override val ZERO = BigDecimal(BigInteger.ZERO)
         override val ONE = BigDecimal(BigInteger.ONE)
         override val TWO = BigDecimal(BigInteger.TWO)
-        override val TEN = BigDecimal(BigInteger.TEN)
+        override val TEN = BigDecimal(BigInteger.TEN, _exponent = 1)
 
         var useToStringExpanded: Boolean = false
 
@@ -1062,7 +1062,11 @@ class BigDecimal private constructor(
      */
     fun divide(other: BigDecimal, decimalMode: DecimalMode? = null): BigDecimal {
         val resolvedDecimalMode = resolveDecimalMode(this.decimalMode, other.decimalMode, decimalMode)
-        var newExponent = this.exponent - other.exponent - 1
+        var newExponent = if (resolvedDecimalMode.isPrecisionUnlimited) {
+            this.exponent - other.exponent
+        } else {
+            this.exponent - other.exponent - 1
+        }
 
         val desiredPrecision = if (resolvedDecimalMode.isPrecisionUnlimited) {
             val precisionSum = max(6, this.precision + other.precision)

diff --git a/bignum/src/commonTest/kotlin/com/ionspin/kotlin/bignum/decimal/BigDecimalDivisionTest.kt b/bignum/src/commonTest/kotlin/com/ionspin/kotlin/bignum/decimal/BigDecimalDivisionTest.kt
@@ -0,0 +1,44 @@
+package com.ionspin.kotlin.bignum.decimal
+
+import kotlin.test.Test
+import kotlin.test.assertFailsWith
+import kotlin.test.assertTrue
+
+/**
+ * Created by Ugljesa Jovanovic
+ * ugljesa.jovanovic@ionspin.com
+ * on 08-Oct-2020
+ */
+class BigDecimalDivisionTest {
+    @Test
+    fun testInfinitePrecisionDivision() {
+        assertTrue {
+            val a = 2.2.toBigDecimal()
+            val b = 2.toBigDecimal()
+            val result = a / b
+            result == 1.1.toBigDecimal()
+        }
+        assertTrue {
+            val a = 2000.212.toBigDecimal()
+            val b = 2.toBigDecimal()
+            val result = a / b
+            result == 1000.106.toBigDecimal()
+        }
+
+        assertTrue {
+            val a = 202020.toBigDecimal()
+            val b = 20.toBigDecimal()
+            val result = a / b
+            result == 10101.toBigDecimal()
+        }
+    }
+
+    @Test
+    fun testInfinitePrecisionNonTerminating() {
+        val a = 1.toBigDecimal()
+        val b = 3.toBigDecimal()
+        assertFailsWith<ArithmeticException> {
+            val result = a / b
+        }
+    }
+}
diff --git a/bignum/src/jvmTest/kotlin/com/ionspin/kotlin/bignum/decimal/BigDecimalNarrowingTest.kt b/bignum/src/jvmTest/kotlin/com/ionspin/kotlin/bignum/decimal/BigDecimalNarrowingTest.kt
@@ -18,7 +18,7 @@ class JvmBigDecimalNarrowingTest {
         val dub = BigDecimal.fromDouble(Double.MIN_VALUE)
         val dub2 = dub.divide(BigDecimal.TEN)
         assertTrue(dub2 < dub)
-        val dub3 = dub.multiply(BigDecimal.TEN)
+        val dub3 = dub2.multiply(BigDecimal.TEN)
         val realDub = dub3.doubleValue(true)
         assertEquals(Double.MIN_VALUE, realDub)
 

diff --git a/buildSrc/src/main/kotlin/Deps.kt b/buildSrc/src/main/kotlin/Deps.kt
@@ -17,10 +17,10 @@
 
 object Versions {
     val kotlinCoroutines = "1.3.9"
-    val kotlin = "1.4.0"
-    val kotlinSerialization = "1.0.0-RC"
+    val kotlin = "1.4.10"
+    val kotlinSerialization = "1.0.0"
     val nodePlugin = "1.3.0"
-    val dokkaPlugin = "1.4.0-rc"
+    val dokkaPlugin = "1.4.10"
 }
 
 object Deps {