IntInSlice and StringInSlice functions

Refs https://github.com/tendermint/tendermint/pull/835

common/int.go

@@ -53,3 +53,13 @@ func PutInt64BE(dest []byte, i int64) {
 func GetInt64BE(src []byte) int64 {
 	return int64(binary.BigEndian.Uint64(src))
 }
+
+// IntInSlice returns true if a is found in the list.
+func IntInSlice(a int, list []int) bool {
+	for _, b := range list {
+		if b == a {
+			return true
+		}
+	}
+	return false
+}

common/int_test.go

@@ -0,0 +1,14 @@
+package common
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestIntInSlice(t *testing.T) {
+	assert.True(t, IntInSlice(1, []int{1, 2, 3}))
+	assert.False(t, IntInSlice(4, []int{1, 2, 3}))
+	assert.True(t, IntInSlice(0, []int{0}))
+	assert.False(t, IntInSlice(0, []int{}))
+}

common/string.go

@@ -43,3 +43,13 @@ func StripHex(s string) string {
 	}
 	return s
 }
+
+// StringInSlice returns true if a is found the list.
+func StringInSlice(a string, list []string) bool {
+	for _, b := range list {
+		if b == a {
+			return true
+		}
+	}
+	return false
+}

common/string_test.go

@@ -0,0 +1,14 @@
+package common
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestStringInSlice(t *testing.T) {
+	assert.True(t, StringInSlice("a", []string{"a", "b", "c"}))
+	assert.False(t, StringInSlice("d", []string{"a", "b", "c"}))
+	assert.True(t, StringInSlice("", []string{""}))
+	assert.False(t, StringInSlice("", []string{}))
+}