Move common function into existing file

middleware/middleware_test.go

@@ -1,8 +1,11 @@
 package middleware
 
 import (
+	"fmt"
 	"net/http"
+	"net/http/httptest"
 	"testing"
+	"time"
 )
 
 func TestIndexfile(t *testing.T) {
@@ -42,3 +45,64 @@ func TestIndexfile(t *testing.T) {
 		}
 	}
 }
+
+func TestSetLastModified(t *testing.T) {
+	nowTime := time.Now()
+
+	// ovewrite the function to return reliable time
+	originalGetCurrentTimeFunc := currentTime
+	currentTime = func() time.Time {
+		return nowTime
+	}
+	defer func() {
+		currentTime = originalGetCurrentTimeFunc
+	}()
+
+	pastTime := nowTime.Truncate(1 * time.Hour)
+	futureTime := nowTime.Add(1 * time.Hour)
+
+	tests := []struct {
+		inputModTime         time.Time
+		expectedIsHeaderSet  bool
+		expectedLastModified string
+	}{
+		{
+			inputModTime:         pastTime,
+			expectedIsHeaderSet:  true,
+			expectedLastModified: pastTime.UTC().Format(http.TimeFormat),
+		},
+		{
+			inputModTime:         nowTime,
+			expectedIsHeaderSet:  true,
+			expectedLastModified: nowTime.UTC().Format(http.TimeFormat),
+		},
+		{
+			inputModTime:         futureTime,
+			expectedIsHeaderSet:  true,
+			expectedLastModified: nowTime.UTC().Format(http.TimeFormat),
+		},
+		{
+			inputModTime:        time.Time{},
+			expectedIsHeaderSet: false,
+		},
+	}
+
+	for i, test := range tests {
+		responseRecorder := httptest.NewRecorder()
+		errorPrefix := fmt.Sprintf("Test [%d]: ", i)
+		SetLastModifiedHeader(responseRecorder, test.inputModTime)
+		actualLastModifiedHeader := responseRecorder.Header().Get("Last-Modified")
+
+		if test.expectedIsHeaderSet && actualLastModifiedHeader == "" {
+			t.Fatalf(errorPrefix + "Expected to find Last-Modified header, but found nothing")
+		}
+
+		if !test.expectedIsHeaderSet && actualLastModifiedHeader != "" {
+			t.Fatalf(errorPrefix+"Did not expect to find Last-Modified header, but found one [%s].", actualLastModifiedHeader)
+		}
+
+		if test.expectedLastModified != actualLastModifiedHeader {
+			t.Errorf(errorPrefix+"Expected Last-Modified content [%s], found [%s}", test.expectedLastModified, actualLastModifiedHeader)
+		}
+	}
+}