Merge pull request #115 from jarcoal/responder-delay

feat(Responder): add Delay(time.Duration) method

response.go

@@ -10,6 +10,7 @@ import (
 	"strconv"
 	"strings"
 	"sync"
+	"time"
 
 	"github.com/jarcoal/httpmock/internal"
 )
@@ -101,6 +102,26 @@ func (r Responder) Trace(fn func(...interface{})) Responder {
 	}
 }
 
+// Delay returns a new Responder that calls the original r Responder
+// after a delay of d.
+//   import (
+//     "testing"
+//     "time"
+//     "github.com/jarcoal/httpmock"
+//   )
+//   ...
+//   func TestMyApp(t *testing.T) {
+//     ...
+//     httpmock.RegisterResponder("GET", "/foo/bar",
+//       httpmock.NewStringResponder(200, "{}").Delay(100*time.Millisecond),
+//     )
+func (r Responder) Delay(d time.Duration) Responder {
+	return func(req *http.Request) (*http.Response, error) {
+		time.Sleep(d)
+		return r(req)
+	}
+}
+
 // ResponderFromResponse wraps an *http.Response in a Responder.
 //
 // Be careful, except for responses generated by httpmock

response_test.go

@@ -9,6 +9,7 @@ import (
 	"strings"
 	"sync"
 	"testing"
+	"time"
 
 	. "github.com/jarcoal/httpmock"
 	"github.com/jarcoal/httpmock/internal"
@@ -597,6 +598,17 @@ func TestResponder(t *testing.T) {
 
 	chk(rt, resp, "")
 	chkCalled()
+
+	//
+	// Delay
+	rt = r.Delay(100 * time.Millisecond)
+	before := time.Now()
+	chk(rt, resp, "")
+	duration := time.Since(before)
+	chkCalled()
+	if duration < 100*time.Millisecond {
+		t.Errorf("Responder is not delayed, only %s elapsed", duration)
+	}
 }
 
 func TestParallelResponder(t *testing.T) {