Initial commit

common/utils/maths.go

@@ -0,0 +1,39 @@
+package utils
+
+import (
+	"fmt"
+	"math/rand"
+)
+
+func RandDigits(n uint) string {
+	s := ""
+	for n != 0 {
+		s += fmt.Sprintf("%d", rand.Intn(10))
+		n--
+	}
+	return s
+}
+
+const lowerLetter = "abcdefghijklmnopqrstuvwxyz"
+
+func RandLowerString(n int) string {
+	b := make([]byte, n)
+	for i := range b {
+		b[i] = lowerLetter[rand.Intn(len(lowerLetter))]
+	}
+	return string(b)
+}
+
+func GetRandomUserName(base string, len int) string {
+	return base + RandDigits(2) + RandLowerString(len)
+}
+
+const letterBytes = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
+
+func RandStringBytes(n int) string {
+	b := make([]byte, n)
+	for i := range b {
+		b[i] = letterBytes[rand.Intn(len(letterBytes))]
+	}
+	return string(b)
+}