add SplitAndTrim func (#183)

Refs https://github.com/tendermint/tendermint/issues/1380

common/string.go

@@ -41,3 +41,20 @@ func StringInSlice(a string, list []string) bool {
 	}
 	return false
 }
+
+// SplitAndTrim slices s into all subslices separated by sep and returns a
+// slice of the string s with all leading and trailing Unicode code points
+// contained in cutset removed. If sep is empty, SplitAndTrim splits after each
+// UTF-8 sequence. First part is equivalent to strings.SplitN with a count of
+// -1.
+func SplitAndTrim(s, sep, cutset string) []string {
+	if s == "" {
+		return []string{}
+	}
+
+	spl := strings.Split(s, sep)
+	for i := 0; i < len(spl); i++ {
+		spl[i] = strings.Trim(spl[i], cutset)
+	}
+	return spl
+}

common/string_test.go

@@ -30,3 +30,22 @@ func TestIsHex(t *testing.T) {
 		assert.True(t, IsHex(v), "%q is hex", v)
 	}
 }
+
+func TestSplitAndTrim(t *testing.T) {
+	testCases := []struct {
+		s        string
+		sep      string
+		cutset   string
+		expected []string
+	}{
+		{"a,b,c", ",", " ", []string{"a", "b", "c"}},
+		{" a , b , c ", ",", " ", []string{"a", "b", "c"}},
+		{" a, b, c ", ",", " ", []string{"a", "b", "c"}},
+		{" , ", ",", " ", []string{"", ""}},
+		{"   ", ",", " ", []string{""}},
+	}
+
+	for _, tc := range testCases {
+		assert.Equal(t, tc.expected, SplitAndTrim(tc.s, tc.sep, tc.cutset), "%s", tc.s)
+	}
+}