From 0378c681e8765478b1f16e813672e26198c6fac5 Mon Sep 17 00:00:00 2001
From: Victor Blomqvist <blomqvist@p1.cn>
Date: Thu, 12 Sep 2013 13:24:50 +0800
Subject: [PATCH] added new assert WithinDuration

---
 assert/assertions.go      | 16 ++++++++++++++++
 assert/assertions_test.go | 12 ++++++++++++
 assert/doc.go             |  3 +++
 3 files changed, 31 insertions(+)

diff --git a/assert/assertions.go b/assert/assertions.go
index 179661e..cc027cb 100644
--- a/assert/assertions.go
+++ b/assert/assertions.go
@@ -6,6 +6,7 @@ import (
 	"runtime"
 	"strings"
 	"testing"
+	"time"
 )
 
 // Comparison a custom function that returns true on success and false on failure
@@ -414,6 +415,21 @@ func NotPanics(t *testing.T, f PanicTestFunc, msgAndArgs ...interface{}) bool {
 	return true
 }
 
+// WithinDuration asserts that the two times are within duration delta of each other.
+//
+//   assert.WithinDuration(t, time.Now(), time.Now(), 10*time.Second, "The difference should not be more than 10s")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func WithinDuration(t *testing.T, a, b time.Time, delta time.Duration, msgAndArgs ...interface{}) bool {
+
+	dt := a.Sub(b)
+	if dt < -delta || dt > delta {
+		return Fail(t, fmt.Sprintf("Max difference between %v and %v allowed is %v, but difference was %v", a, b, dt, delta), msgAndArgs...)
+	}
+
+	return true
+}
+
 /*
 	Errors
 */
diff --git a/assert/assertions_test.go b/assert/assertions_test.go
index e7ea5a9..0c3a821 100644
--- a/assert/assertions_test.go
+++ b/assert/assertions_test.go
@@ -3,6 +3,7 @@ package assert
 import (
 	"errors"
 	"testing"
+	"time"
 )
 
 // AssertionTesterInterface defines an interface to be used for testing assertion methods
@@ -361,3 +362,14 @@ func TestNotEmpty(t *testing.T) {
 	True(t, NotEmpty(mockT, true), "True value is not empty")
 
 }
+
+func TestWithinDuration(t *testing.T) {
+
+	mockT := new(testing.T)
+	a := time.Now()
+	b := a.Add(10 * time.Second)
+
+	True(t, WithinDuration(mockT, a, b, 10*time.Second), "A 10s difference is within a 10s time difference")
+
+	False(t, WithinDuration(mockT, a, b, 9*time.Second), "A 10s difference is not within a 9s time difference")
+}
diff --git a/assert/doc.go b/assert/doc.go
index 17397e3..25f699b 100644
--- a/assert/doc.go
+++ b/assert/doc.go
@@ -68,4 +68,7 @@
 //	    // call code that should not panic
 //
 //    } [, message [, format-args]])
+//
+//    assert.WithinDuration(t, timeA, timeB, deltaTime, [, message [, format-args]])
+
 package assert