Commit 5a29107f authored by makpoc's avatar makpoc

Add Last-Modified header when serving markdown and templates

parent 136119f8
package middleware
import (
"net/http"
"time"
)
// currentTime returns time.Now() everytime it's called. It's used for mocking in tests.
var currentTime = func() time.Time {
return time.Now()
}
// SetLastModifiedHeader checks if the provided modTime is valid and if it is sets it
// as a Last-Modified header to the ResponseWriter. If the modTime is in the future
// the current time is used instead.
func SetLastModifiedHeader(w http.ResponseWriter, modTime time.Time) {
if modTime.IsZero() || modTime.Equal(time.Unix(0, 0)) {
// the time does not appear to be valid. Don't put it in the response
return
}
// RFC 2616 - Section 14.29 - Last-Modified:
// An origin server MUST NOT send a Last-Modified date which is later than the
// server's time of message origination. In such cases, where the resource's last
// modification would indicate some time in the future, the server MUST replace
// that date with the message origination date.
now := currentTime()
if modTime.After(now) {
modTime = now
}
w.Header().Set("Last-Modified", modTime.UTC().Format(http.TimeFormat))
}
package middleware
import (
"fmt"
"net/http"
"net/http/httptest"
"testing"
"time"
)
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)
}
}
}
......@@ -136,6 +136,7 @@ func (md Markdown) ServeHTTP(w http.ResponseWriter, r *http.Request) (int, error
// generation, serve the static page
if fs.ModTime().Before(fs1.ModTime()) {
if html, err := ioutil.ReadFile(filepath); err == nil {
middleware.SetLastModifiedHeader(w, fs1.ModTime())
w.Write(html)
return http.StatusOK, nil
}
......@@ -162,6 +163,7 @@ func (md Markdown) ServeHTTP(w http.ResponseWriter, r *http.Request) (int, error
return http.StatusInternalServerError, err
}
middleware.SetLastModifiedHeader(w, fs.ModTime())
w.Write(html)
return http.StatusOK, nil
}
......
......@@ -34,7 +34,8 @@ func (t Templates) ServeHTTP(w http.ResponseWriter, r *http.Request) (int, error
ctx := middleware.Context{Root: t.FileSys, Req: r, URL: r.URL}
// Build the template
tpl, err := template.ParseFiles(filepath.Join(t.Root, fpath))
templatePath := filepath.Join(t.Root, fpath)
tpl, err := template.ParseFiles(templatePath)
if err != nil {
if os.IsNotExist(err) {
return http.StatusNotFound, nil
......@@ -50,6 +51,12 @@ func (t Templates) ServeHTTP(w http.ResponseWriter, r *http.Request) (int, error
if err != nil {
return http.StatusInternalServerError, err
}
templateInfo, err := os.Stat(templatePath)
if err == nil {
// add the Last-Modified header if we were able to optain the information
middleware.SetLastModifiedHeader(w, templateInfo.ModTime())
}
buf.WriteTo(w)
return http.StatusOK, nil
......
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