Validate coins denom upon creation

Disallow empty denoms.

Author: Alessio Treglia

types/coin.go

@@ -1,6 +1,7 @@
 package types
 
 import (
+	"errors"
 	"fmt"
 	"regexp"
 	"sort"
@@ -30,6 +31,9 @@ func NewCoin(denom string, amount Int) Coin {
 	if amount.LT(ZeroInt()) {
 		panic(fmt.Sprintf("negative coin amount: %v\n", amount))
 	}
+	if len(strings.TrimSpace(denom)) == 0 {
+		panic(errors.New("denom cannot be an empty string\n"))
+	}
 	if strings.ToLower(denom) != denom {
 		panic(fmt.Sprintf("denom cannot contain upper case characters: %s\n", denom))
 	}

types/coin_test.go

@@ -452,55 +452,36 @@ func TestSortCoins(t *testing.T) {
 func TestAmountOf(t *testing.T) {
 	case0 := Coins{}
 	case1 := Coins{
-		NewInt64Coin("", 0),
-	}
-	case2 := Coins{
-		NewInt64Coin(" ", 0),
-	}
-	case3 := Coins{
 		NewInt64Coin("gold", 0),
 	}
-	case4 := Coins{
+	case2 := Coins{
 		NewInt64Coin("gas", 1),
 		NewInt64Coin("mineral", 1),
 		NewInt64Coin("tree", 1),
 	}
-	case5 := Coins{
+	case3 := Coins{
 		NewInt64Coin("mineral", 1),
 		NewInt64Coin("tree", 1),
 	}
-	case6 := Coins{
-		NewInt64Coin("", 6),
-	}
-	case7 := Coins{
-		NewInt64Coin(" ", 7),
-	}
-	case8 := Coins{
+	case4 := Coins{
 		NewInt64Coin("gas", 8),
 	}
 
 	cases := []struct {
 		coins           Coins
 		amountOf        int64
-		amountOfSpace   int64
 		amountOfGAS     int64
 		amountOfMINERAL int64
 		amountOfTREE    int64
 	}{
-		{case0, 0, 0, 0, 0, 0},
-		{case1, 0, 0, 0, 0, 0},
-		{case2, 0, 0, 0, 0, 0},
-		{case3, 0, 0, 0, 0, 0},
-		{case4, 0, 0, 1, 1, 1},
-		{case5, 0, 0, 0, 1, 1},
-		{case6, 6, 0, 0, 0, 0},
-		{case7, 0, 7, 0, 0, 0},
-		{case8, 0, 0, 8, 0, 0},
+		{case0, 0, 0, 0, 0},
+		{case1, 0, 0, 0, 0},
+		{case2, 0, 1, 1, 1},
+		{case3, 0, 0, 1, 1},
+		{case4, 0, 8, 0, 0},
 	}
 
 	for _, tc := range cases {
-		assert.Equal(t, NewInt(tc.amountOf), tc.coins.AmountOf(""))
-		assert.Equal(t, NewInt(tc.amountOfSpace), tc.coins.AmountOf(" "))
 		assert.Equal(t, NewInt(tc.amountOfGAS), tc.coins.AmountOf("gas"))
 		assert.Equal(t, NewInt(tc.amountOfMINERAL), tc.coins.AmountOf("mineral"))
 		assert.Equal(t, NewInt(tc.amountOfTREE), tc.coins.AmountOf("tree"))

types/dec_coin.go

@@ -22,6 +22,9 @@ func NewDecCoin(denom string, amount int64) DecCoin {
 	if amount < 0 {
 		panic(fmt.Sprintf("negative decimal coin amount: %v\n", amount))
 	}
+	if len(strings.TrimSpace(denom)) == 0 {
+		panic(errors.New("denom cannot be an empty string\n"))
+	}
 	if strings.ToLower(denom) != denom {
 		panic(fmt.Sprintf("denom cannot contain upper case characters: %s\n", denom))
 	}