Push resources for indexFiles when surfing to directories

Use httpserver.IndexFile() to determine index files

Test if middleware pushes indexfile when requesting directory

Fix codereview issues

Serve original request first, push later

Revert "Serve original request first, push later"

This reverts commit 2c66f01115747e5665ba7f2d33e2fd551dc31877.

caddyhttp/push/handler.go

@@ -5,6 +5,7 @@ import (
 	"strings"
 
 	"github.com/mholt/caddy/caddyhttp/httpserver"
+	"github.com/mholt/caddy/caddyhttp/staticfiles"
 )
 
 func (h Middleware) ServeHTTP(w http.ResponseWriter, r *http.Request) (int, error) {
@@ -25,7 +26,13 @@ func (h Middleware) ServeHTTP(w http.ResponseWriter, r *http.Request) (int, erro
 	// push first
 outer:
 	for _, rule := range h.Rules {
-		if httpserver.Path(r.URL.Path).Matches(rule.Path) {
+		urlPath := r.URL.Path
+		matches := httpserver.Path(urlPath).Matches(rule.Path)
+		// Also check IndexPages when requesting a directory
+		if !matches {
+			_, matches = httpserver.IndexFile(h.Root, urlPath, staticfiles.IndexPages)
+		}
+		if matches {
 			for _, resource := range rule.Resources {
 				pushErr := pusher.Push(resource.Path, &http.PushOptions{
 					Method: resource.Method,