httpserver: rename context Push action for more general use (#1641)

Signed-off-by: Tw <tw19881113@gmail.com>

caddyhttp/httpserver/tplcontext.go

@@ -424,12 +424,13 @@ func (c Context) RandomString(minLen, maxLen int) string {
 	return string(result)
 }
 
-// Push adds a preload link in response header for server push
-func (c Context) Push(link string) string {
+// AddLink adds a link header in response
+// see https://www.w3.org/wiki/LinkHeader
+func (c Context) AddLink(link string) string {
 	if c.responseHeader == nil {
 		return ""
 	}
-	c.responseHeader.Add("Link", "<"+link+">; rel=preload")
+	c.responseHeader.Add("Link", link)
 	return ""
 }
 

caddyhttp/httpserver/tplcontext_test.go

@@ -877,18 +877,18 @@ func TestFiles(t *testing.T) {
 	}
 }
 
-func TestPush(t *testing.T) {
+func TestAddLink(t *testing.T) {
 	for name, c := range map[string]struct {
 		input       string
 		expectLinks []string
 	}{
 		"oneLink": {
-			input:       `{{.Push "/test.css"}}`,
+			input:       `{{.AddLink "</test.css>; rel=preload"}}`,
 			expectLinks: []string{"</test.css>; rel=preload"},
 		},
 		"multipleLinks": {
-			input:       `{{.Push "/test1.css"}} {{.Push "/test2.css"}}`,
-			expectLinks: []string{"</test1.css>; rel=preload", "</test2.css>; rel=preload"},
+			input:       `{{.AddLink "</test1.css>; rel=preload"}} {{.AddLink "</test2.css>; rel=meta"}}`,
+			expectLinks: []string{"</test1.css>; rel=preload", "</test2.css>; rel=meta"},
 		},
 	} {
 		c := c