added min(), max(), average() and median() to MoneyList

build.gradle

@@ -7,7 +7,7 @@ buildscript {
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.0.0-rc1'
+        classpath 'com.android.tools.build:gradle:3.0.0'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
         classpath 'com.github.dcendents:android-maven-gradle-plugin:1.5'
 

money/src/main/java/de/tobiasschuerg/money/CurrencyCode.kt

@@ -1,6 +1,5 @@
 package de.tobiasschuerg.money
 
-import android.util.Log
 import java.util.*
 
 
@@ -16,7 +15,7 @@ data class CurrencyCode(val code: String) {
         try {
             symbol = java.util.Currency.getInstance(code).symbol
         } catch (ia: IllegalArgumentException) {
-            Log.w("Currency Code", "Could not find symbol for $code")
+            // Log.w("Currency Code", "Could not find symbol for $code")
             symbol = code
         }
         return symbol

money/src/main/java/de/tobiasschuerg/money/MoneyList.kt

@@ -1,5 +1,7 @@
 package de.tobiasschuerg.money
 
+import java.math.BigDecimal
+
 /**
  * List of money which provides additional features such as sum, average, median etc...
  *
@@ -104,4 +106,25 @@ class MoneyList(private val currency: Currency, val autoConvert: Boolean = false
     }
 
     fun sum(): Money = sum
+
+    fun min(): Money? = list.minBy(Money::amount)
+
+    fun max(): Money? = list.maxBy(Money::amount)
+
+    fun median(): Money? {
+        if (list.isNotEmpty()) {
+            val index: Int = list.size / 2
+            return list.sortedBy(Money::amount)[index]
+        } else {
+            return null
+        }
+    }
+
+    fun average(): Money? {
+        return if (list.isNotEmpty()) {
+            sum / BigDecimal(list.size)
+        } else {
+            null
+        }
+    }
 }

money/src/test/java/de/tobiasschuerg/money/MoneyArithmeticsTest.kt

@@ -72,7 +72,5 @@ class MoneyArithmeticsTest {
         val result1Minus = Money(amount1 - amount2, EURO)
         val result2Minus = money1 - money2
         Assert.assertEquals(result2Minus, result1Minus)
-
-
     }
 }

money/src/test/java/de/tobiasschuerg/money/MoneyListTest.kt

@@ -0,0 +1,43 @@
+package de.tobiasschuerg.money
+
+import org.junit.Assert
+import org.junit.Test
+
+/**
+ * Created by Tobias Schürg on 05.11.2017.
+ */
+class MoneyListTest {
+
+    private val currency = Currency("TST", "TEST", 1.0)
+    private val list = MoneyList(currency)
+
+    init {
+        list.add(Money(3, currency))
+        list.add(Money(2, currency))
+        list.add(Money(6, currency))
+        list.add(Money(1, currency)) // min
+        list.add(Money(4, currency))
+        list.add(Money(9, currency)) // max
+        list.add(Money(7, currency))
+        list.add(Money(5, currency))
+        list.add(Money(8, currency))
+    }
+
+    @Test
+    fun minMax() {
+        Assert.assertEquals(Money(1, currency), list.min())
+        Assert.assertEquals(Money(9, currency), list.max())
+        Assert.assertEquals(Money(5, currency), list.average())
+        Assert.assertEquals(Money(5, currency), list.median())
+    }
+
+    @Test
+    fun minMaxEmptyList() {
+        val emptyList = MoneyList(currency)
+        Assert.assertNull(emptyList.min())
+        Assert.assertNull(emptyList.max())
+        Assert.assertNull(emptyList.average())
+        Assert.assertNull(emptyList.median())
+    }
+
+}