rand func modify

utils/rand.go

@@ -20,28 +20,24 @@ import (
 	"time"
 )
 
+var alphaNum = []byte(`0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz`)
+
 // RandomCreateBytes generate random []byte by specify chars.
 func RandomCreateBytes(n int, alphabets ...byte) []byte {
-	const alphanum = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
+	if len(alphabets) == 0 {
+		alphabets = alphaNum
+	}
 	var bytes = make([]byte, n)
-	var randby bool
+	var randBy bool
 	if num, err := rand.Read(bytes); num != n || err != nil {
 		r.Seed(time.Now().UnixNano())
-		randby = true
+		randBy = true
 	}
 	for i, b := range bytes {
-		if len(alphabets) == 0 {
-			if randby {
-				bytes[i] = alphanum[r.Intn(len(alphanum))]
-			} else {
-				bytes[i] = alphanum[b%byte(len(alphanum))]
-			}
+		if randBy {
+			bytes[i] = alphabets[r.Intn(len(alphabets))]
 		} else {
-			if randby {
-				bytes[i] = alphabets[r.Intn(len(alphabets))]
-			} else {
-				bytes[i] = alphabets[b%byte(len(alphabets))]
-			}
+			bytes[i] = alphabets[b%byte(len(alphabets))]
 		}
 	}
 	return bytes

utils/rand_test.go

+// Copyright 2016 beego Author. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package utils
+
+import "testing"
+
+func TestRand_01(t *testing.T) {
+	bs0 := RandomCreateBytes(16)
+	bs1 := RandomCreateBytes(16)
+
+	t.Log(string(bs0), string(bs1))
+	if string(bs0) == string(bs1) {
+		t.FailNow()
+	}
+
+	bs0 = RandomCreateBytes(4, []byte(`a`)...)
+
+	if string(bs0) != "aaaa" {
+		t.FailNow()
+	}
+}