time: add tests for Tick, NewTicker with negative duration

R=golang-codereviews, gobot, r, bradfitz
CC=golang-codereviews
https://golang.org/cl/37660044

diff --git a/src/pkg/time/tick_test.go b/src/pkg/time/tick_test.go
index d8a086ceb2548725c90ecd670571386d185d435e..32f4740ad93cbcaad8e2460fef270eef9046994c 100644 (file)
--- a/src/pkg/time/tick_test.go
+++ b/src/pkg/time/tick_test.go
@@ -48,6 +48,24 @@ func TestTeardown(t *testing.T) {
        }
 }
 
+// Test the Tick convenience wrapper.
+func TestTick(t *testing.T) {
+       // Test that giving a negative duration returns nil.
+       if got := Tick(-1); got != nil {
+               t.Errorf("Tick(-1) = %v; want nil", got)
+       }
+}
+
+// Test that NewTicker panics when given a duration less than zero.
+func TestNewTickerLtZeroDuration(t *testing.T) {
+       defer func() {
+               if err := recover(); err == nil {
+                       t.Errorf("NewTicker(-1) should have panicked")
+               }
+       }()
+       NewTicker(-1)
+}
+
 func BenchmarkTicker(b *testing.B) {
        ticker := NewTicker(1)
        b.ResetTimer()