From 26c040537f19c9c24c940f0d1a2a994a1567baac Mon Sep 17 00:00:00 2001
From: V2Ray <admin@v2ray.com>
Date: Thu, 17 Sep 2015 00:15:06 +0200
Subject: [PATCH] test cases for rand

---
 math/rand_test.go            | 20 +++++++++++++
 testing/unit/assertions.go   |  4 +++
 testing/unit/int64subject.go | 54 ++++++++++++++++++++++++++++++++++++
 3 files changed, 78 insertions(+)
 create mode 100644 math/rand_test.go
 create mode 100644 testing/unit/int64subject.go

diff --git a/math/rand_test.go b/math/rand_test.go
new file mode 100644
index 000000000..1d31e81ea
--- /dev/null
+++ b/math/rand_test.go
@@ -0,0 +1,20 @@
+package math
+
+import (
+	"testing"
+	"time"
+
+	"github.com/v2ray/v2ray-core/testing/unit"
+)
+
+func TestGenerateRandomInt64InRange(t *testing.T) {
+	assert := unit.Assert(t)
+	base := time.Now().Unix()
+	delta := 100
+
+	for i := 0; i < 100; i++ {
+		v := GenerateRandomInt64InRange(base, delta)
+		assert.Int64(v).AtMost(base + int64(delta))
+		assert.Int64(v).AtLeast(base - int64(delta))
+	}
+}
diff --git a/testing/unit/assertions.go b/testing/unit/assertions.go
index bb85507a7..fe5b2cfc4 100644
--- a/testing/unit/assertions.go
+++ b/testing/unit/assertions.go
@@ -16,6 +16,10 @@ func Assert(t *testing.T) *Assertion {
 	return assert
 }
 
+func (a *Assertion) Int64(value int64) *Int64Subject {
+	return NewInt64Subject(NewSubject(a), value)
+}
+
 func (a *Assertion) Int(value int) *IntSubject {
 	return NewIntSubject(NewSubject(a), value)
 }
diff --git a/testing/unit/int64subject.go b/testing/unit/int64subject.go
new file mode 100644
index 000000000..59c3d9c8b
--- /dev/null
+++ b/testing/unit/int64subject.go
@@ -0,0 +1,54 @@
+package unit
+
+import (
+	"strconv"
+)
+
+type Int64Subject struct {
+	*Subject
+	value int64
+}
+
+func NewInt64Subject(base *Subject, value int64) *Int64Subject {
+	return &Int64Subject{
+		Subject: base,
+		value:   value,
+	}
+}
+
+func (subject *Int64Subject) Named(name string) *Int64Subject {
+	subject.Subject.Named(name)
+	return subject
+}
+
+func (subject *Int64Subject) Fail(verb string, other int64) {
+	subject.FailWithMessage("Not true that " + subject.DisplayString() + " " + verb + " <" + strconv.FormatInt(other, 10) + ">.")
+}
+
+func (subject *Int64Subject) DisplayString() string {
+	return subject.Subject.DisplayString(strconv.FormatInt(subject.value, 10))
+}
+
+func (subject *Int64Subject) Equals(expectation int64) {
+	if subject.value != expectation {
+		subject.Fail("is equal to", expectation)
+	}
+}
+
+func (subject *Int64Subject) GreaterThan(expectation int64) {
+	if subject.value <= expectation {
+		subject.Fail("is greater than", expectation)
+	}
+}
+
+func (subject *Int64Subject) AtMost(expectation int64) {
+	if subject.value > expectation {
+		subject.Fail("is at most", expectation)
+	}
+}
+
+func (subject *Int64Subject) AtLeast(expectation int64) {
+	if subject.value < expectation {
+		subject.Fail("is at least", expectation)
+	}
+}