Bind livereload to the same port as hugo

If hugo is run with port 80 or 443, live reload does not
correctly bind to the same port, instead using port 35729.
This commit adds functionality to inform livereload of the
correct port to bind to.

Fixes gohugoio#2205

transform/livereloadinject.go

@@ -16,18 +16,22 @@ package transform
 import (
 	"bytes"
 	"fmt"
+
+	"github.com/spf13/viper"
 )
 
 func LiveReloadInject(ct contentTransformer) {
 	endBodyTag := "</body>"
 	match := []byte(endBodyTag)
-	replaceTemplate := `<script data-no-instant>document.write('<script src="/livereload.js?mindelay=10"></' + 'script>')</script>%s`
-	replace := []byte(fmt.Sprintf(replaceTemplate, endBodyTag))
+	port := viper.Get("port")
+
+	replaceTemplate := `<script data-no-instant>document.write('<script src="/livereload.js?port=%d&mindelay=10"></' + 'script>')</script>%s`
+	replace := []byte(fmt.Sprintf(replaceTemplate, port, endBodyTag))
 
 	newcontent := bytes.Replace(ct.Content(), match, replace, 1)
 	if len(newcontent) == len(ct.Content()) {
 		endBodyTag = "</BODY>"
-		replace := []byte(fmt.Sprintf(replaceTemplate, endBodyTag))
+		replace := []byte(fmt.Sprintf(replaceTemplate, port, endBodyTag))
 		match := []byte(endBodyTag)
 		newcontent = bytes.Replace(ct.Content(), match, replace, 1)
 	}

transform/livereloadinject_test.go

@@ -17,6 +17,7 @@ import (
 	"bytes"
 	"fmt"
 	"github.com/spf13/hugo/helpers"
+	"github.com/spf13/viper"
 	"testing"
 )
 
@@ -26,13 +27,15 @@ func TestLiveReloadInject(t *testing.T) {
 }
 
 func doTestLiveReloadInject(t *testing.T, bodyEndTag string) {
+	viper.Set("port", 1313)
+
 	out := new(bytes.Buffer)
 	in := helpers.StringToReader(bodyEndTag)
 
 	tr := NewChain(LiveReloadInject)
 	tr.Apply(out, in, []byte("path"))
 
-	expected := fmt.Sprintf(`<script data-no-instant>document.write('<script src="/livereload.js?mindelay=10"></' + 'script>')</script>%s`, bodyEndTag)
+	expected := fmt.Sprintf(`<script data-no-instant>document.write('<script src="/livereload.js?port=1313&mindelay=10"></' + 'script>')</script>%s`, bodyEndTag)
 	if string(out.Bytes()) != expected {
 		t.Errorf("Expected %s got %s", expected, string(out.Bytes()))
 	}