From 730de27aa507d979cb5a8a17b11c82f361c3d4a3 Mon Sep 17 00:00:00 2001
From: Dan Mayor <dmayor@digivance.com>
Date: Tue, 5 Sep 2017 09:57:20 -0400
Subject: [PATCH] Suggesting Sum and Avg methods (provided unit tests),
 recommending removing val2 from for range loops in TestBinary & TestGobEncode
 (#60)

---
 decimal.go      | 17 +++++++++++++++++
 decimal_test.go | 34 ++++++++++++++++++++++++++++++++--
 2 files changed, 49 insertions(+), 2 deletions(-)

diff --git a/decimal.go b/decimal.go
index fd54cb5..17c8d72 100644
--- a/decimal.go
+++ b/decimal.go
@@ -828,6 +828,23 @@ func Max(first Decimal, rest ...Decimal) Decimal {
 	return ans
 }
 
+// Sum returns the combined total of the provided first and rest Decimals
+func Sum(first Decimal, rest ...Decimal) Decimal {
+	total := first
+	for _, item := range rest {
+		total = total.Add(item)
+	}
+
+	return total
+}
+
+// Avg returns the average value of the provided first and rest Decimals
+func Avg(first Decimal, rest ...Decimal) Decimal {
+	count := New(int64(len(rest)+1), 0)
+	sum := Sum(first, rest...)
+	return sum.Div(count)
+}
+
 func min(x, y int32) int32 {
 	if x >= y {
 		return y
diff --git a/decimal_test.go b/decimal_test.go
index 94d0db7..fc9cb12 100644
--- a/decimal_test.go
+++ b/decimal_test.go
@@ -1654,7 +1654,7 @@ func TestNullDecimal_Value(t *testing.T) {
 }
 
 func TestBinary(t *testing.T) {
-	for x, _ := range testTable {
+	for x := range testTable {
 
 		// Create the decimal
 		d1 := NewFromFloat(x)
@@ -1689,7 +1689,7 @@ func slicesEqual(a, b []byte) bool {
 }
 
 func TestGobEncode(t *testing.T) {
-	for x, _ := range testTable {
+	for x := range testTable {
 		d1 := NewFromFloat(x)
 
 		b1, err := d1.GobEncode()
@@ -1730,3 +1730,33 @@ func TestGobEncode(t *testing.T) {
 		}
 	}
 }
+
+func TestSum(t *testing.T) {
+	vals := make([]Decimal, 10)
+	var i = int64(0)
+
+	for key := range vals {
+		vals[key] = New(i, 0)
+		i++
+	}
+
+	sum := Sum(vals[0], vals[1:]...)
+	if !sum.Equal(New(45, 0)) {
+		t.Errorf("Failed to calculate sum, expected %s got %s", New(45, 0), sum)
+	}
+}
+
+func TestAvg(t *testing.T) {
+	vals := make([]Decimal, 10)
+	var i = int64(0)
+
+	for key := range vals {
+		vals[key] = New(i, 0)
+		i++
+	}
+
+	avg := Avg(vals[0], vals[1:]...)
+	if !avg.Equal(NewFromFloat(4.5)) {
+		t.Errorf("Failed to calculate average, expected %s got %s", NewFromFloat(4.5).String(), avg.String())
+	}
+}