caddyhttp: Add split_path to file matcher (used by php_fastcgi) (#3302)

* matcher: Add `split_path` option to file matcher; used in php_fastcgi

* matcher: Skip try_files split if not the final part of the filename

* matcher: Add MatchFile tests

* matcher: Clarify SplitPath godoc

1 files changed, 11 insertions, 0 deletions

diff --git a/modules/caddyhttp/replacer.go b/modules/caddyhttp/replacer.go
index b83977c..670b2e3 100644
--- a/modules/caddyhttp/replacer.go
+++ b/modules/caddyhttp/replacer.go
@@ -15,6 +15,7 @@
 package caddyhttp
 
 import (
+	"context"
 	"crypto/sha256"
 	"crypto/tls"
 	"crypto/x509"
@@ -30,6 +31,16 @@ import (
 	"github.com/caddyserver/caddy/v2/modules/caddytls"
 )
 
+// NewTestReplacer creates a replacer for an http.Request
+// for use in tests that are not in this package
+func NewTestReplacer(req *http.Request) *caddy.Replacer {
+	repl := caddy.NewReplacer()
+	ctx := context.WithValue(req.Context(), caddy.ReplacerCtxKey, repl)
+	*req = *req.WithContext(ctx)
+	addHTTPVarsToReplacer(repl, req, nil)
+	return repl
+}
+
 func addHTTPVarsToReplacer(repl *caddy.Replacer, req *http.Request, w http.ResponseWriter) {
 	httpVars := func(key string) (interface{}, bool) {
 		if req != nil {