Make HTTP middleware easier to use

server/auth/xsrf/xsrf_test.go

 // Copyright 2015 The LUCI Authors. All rights reserved.
 // Use of this source code is governed under the Apache License, Version 2.0
 // that can be found in the LICENSE file.
 
 package xsrf
 
 import (
         "html/template"
         "net/http"
         "net/http/httptest"
         "net/url"
         "strings"
         "testing"
         "time"
 
         "github.com/julienschmidt/httprouter"
         "golang.org/x/net/context"
 
         "github.com/luci/luci-go/common/clock/testclock"
+        "github.com/luci/luci-go/server/router"
         "github.com/luci/luci-go/server/secrets/testsecrets"
 
         . "github.com/smartystreets/goconvey/convey"
 )
 
 func TestXsrf(t *testing.T) {
         Convey("Token + Check", t, func() {
                 c := makeContext()
                 tok, err := Token(c)
                 So(err, ShouldBeNil)
                 So(Check(c, tok), ShouldBeNil)
                 So(Check(c, tok+"abc"), ShouldNotBeNil)
         })
 
         Convey("TokenField works", t, func() {
                 c := makeContext()
                 So(TokenField(c), ShouldResemble,
                         template.HTML("<input type=\"hidden\" name=\"xsrf_token\" "+
                                 "value=\"AXsiX2kiOiIxNDQyMjcwNTIwMDAwIn1ceiDv1yfNK9OHcdb209l3fM4p_gn-Uaembaa8gr3WXg\">"))
         })
 
         Convey("Middleware works", t, func() {
                 c := makeContext()
                 tok, _ := Token(c)
 
-                h := WithTokenCheck(func(c context.Context, rw http.ResponseWriter, r *http.Request, p httprouter.Params) {
-                        rw.Write([]byte("hi"))
-                })
+                initialize := func(c context.Context, rw http.ResponseWriter, r *http.Request, p httprouter.Params) router.Handler {
+                        return func(ctx *router.Context) {
+                                ctx.Context = c
+                                ctx.Writer = rw
+                                ctx.Request = r
+                                ctx.Params = p
+                        }
+                }
+                handler := func(c *router.Context) {
+                        c.Writer.Write([]byte("hi"))
+                }
 
                 // Has token -> works.
                 rec := httptest.NewRecorder()
                 req := makeRequest(tok)
-                h(c, rec, req, nil)
+                router.ChainHandlers(initialize(c, rec, req, nil), WithTokenCheck(), handler)()
                 So(rec.Code, ShouldEqual, 200)
 
                 // No token.
                 rec = httptest.NewRecorder()
                 req = makeRequest("")
-                h(c, rec, req, nil)
+                router.ChainHandlers(initialize(c, rec, req, nil), WithTokenCheck(), handler)()
                 So(rec.Code, ShouldEqual, 403)
 
                 // Bad token.
                 rec = httptest.NewRecorder()
                 req = makeRequest("blah")
-                h(c, rec, req, nil)
+                router.ChainHandlers(initialize(c, rec, req, nil), WithTokenCheck(), handler)()
                 So(rec.Code, ShouldEqual, 403)
         })
 }
 
 func makeContext() context.Context {
         c := testsecrets.Use(context.Background())
         c, _ = testclock.UseTime(c, time.Unix(1442270520, 0))
         return c
 }
 
 func makeRequest(tok string) *http.Request {
         body := url.Values{}
         if tok != "" {
                 body.Add("xsrf_token", tok)
         }
         req, _ := http.NewRequest("POST", "https://example.com", strings.NewReader(body.Encode()))
         req.Header.Add("Content-Type", "application/x-www-form-urlencoded")
         return req
 }