Add public accessors for request pattern and method (#175)

These are very useful values to be able to access easily while processing requests. Let's make them public and reachable via the context.

Author: tomcoupland

router.go

@@ -14,10 +14,12 @@ import (
 // https://play.golang.org/p/MxhRiL37R-9
 type routerContextKeyType struct{}
 type routerRequestPatternContextKeyType struct{}
+type routerRequestMethodContextKeyType struct{}
 
 var (
 	routerContextKey               = routerContextKeyType{}
 	routerRequestPatternContextKey = routerRequestPatternContextKeyType{}
+	routerRequestMethodContextKey  = routerRequestMethodContextKeyType{}
 	routerComponentsRe             = regexp.MustCompile(`(?:^|/)(\*\w*|:\w+)`)
 )
 
@@ -53,6 +55,22 @@ func routerPathPatternForRequest(r Request) string {
 	return ""
 }
 
+// RequestPatternFromContext returns the pattern that was matched for the request, if available.
+func RequestPatternFromContext(ctx context.Context) (string, bool) {
+	if v := ctx.Value(routerRequestPatternContextKey); v != nil {
+		return v.(string), true
+	}
+	return "", false
+}
+
+// RequestMethodFromContext returns the method of the request, if available.
+func RequestMethodFromContext(ctx context.Context) (string, bool) {
+	if v := ctx.Value(routerRequestMethodContextKey); v != nil {
+		return v.(string), true
+	}
+	return "", false
+}
+
 func (r *Router) compile(pattern string) *regexp.Regexp {
 	re, pos := ``, 0
 	for _, m := range routerComponentsRe.FindAllStringSubmatchIndex(pattern, -1) {
@@ -134,6 +152,7 @@ func (r Router) Serve() Service {
 		}
 		req.Context = context.WithValue(req.Context, routerContextKey, &r)
 		req.Context = context.WithValue(req.Context, routerRequestPatternContextKey, pathPattern)
+		req.Context = context.WithValue(req.Context, routerRequestMethodContextKey, req.Method)
 		rsp := svc(req)
 		if rsp.Request == nil {
 			rsp.Request = &req
@@ -157,37 +176,46 @@ func (r Router) Params(req Request) map[string]string {
 // Sugar
 
 // GET is shorthand for:
-//  r.Register("GET", pattern, svc)
+//
+//	r.Register("GET", pattern, svc)
 func (r *Router) GET(pattern string, svc Service) { r.Register("GET", pattern, svc) }
 
 // CONNECT is shorthand for:
-//  r.Register("CONNECT", pattern, svc)
+//
+//	r.Register("CONNECT", pattern, svc)
 func (r *Router) CONNECT(pattern string, svc Service) { r.Register("CONNECT", pattern, svc) }
 
 // DELETE is shorthand for:
-//  r.Register("DELETE", pattern, svc)
+//
+//	r.Register("DELETE", pattern, svc)
 func (r *Router) DELETE(pattern string, svc Service) { r.Register("DELETE", pattern, svc) }
 
 // HEAD is shorthand for:
-//  r.Register("HEAD", pattern, svc)
+//
+//	r.Register("HEAD", pattern, svc)
 func (r *Router) HEAD(pattern string, svc Service) { r.Register("HEAD", pattern, svc) }
 
 // OPTIONS is shorthand for:
-//  r.Register("OPTIONS", pattern, svc)
+//
+//	r.Register("OPTIONS", pattern, svc)
 func (r *Router) OPTIONS(pattern string, svc Service) { r.Register("OPTIONS", pattern, svc) }
 
 // PATCH is shorthand for:
-//  r.Register("PATCH", pattern, svc)
+//
+//	r.Register("PATCH", pattern, svc)
 func (r *Router) PATCH(pattern string, svc Service) { r.Register("PATCH", pattern, svc) }
 
 // POST is shorthand for:
-//  r.Register("POST", pattern, svc)
+//
+//	r.Register("POST", pattern, svc)
 func (r *Router) POST(pattern string, svc Service) { r.Register("POST", pattern, svc) }
 
 // PUT is shorthand for:
-//  r.Register("PUT", pattern, svc)
+//
+//	r.Register("PUT", pattern, svc)
 func (r *Router) PUT(pattern string, svc Service) { r.Register("PUT", pattern, svc) }
 
 // TRACE is shorthand for:
-//  r.Register("TRACE", pattern, svc)
+//
+//	r.Register("TRACE", pattern, svc)
 func (r *Router) TRACE(pattern string, svc Service) { r.Register("TRACE", pattern, svc) }

router_test.go

@@ -126,3 +126,25 @@ func TestRouterSetsRequest(t *testing.T) {
 	req.Context = rsp.Request.Context
 	assert.Equal(t, req, *rsp.Request)
 }
+
+func TestRouterSetsContextValues(t *testing.T) {
+	t.Parallel()
+
+	router := Router{}
+	router.GET("/", func(req Request) Response {
+		return Response{}
+	})
+
+	ctx := context.Background()
+	req := NewRequest(ctx, "GET", "/", map[string]string{"r": "foo"})
+	rsp := router.Serve()(req)
+	require.NotNil(t, rsp.Request)
+
+	ctxPattern, ok := RequestPatternFromContext(rsp.Request.Context)
+	assert.True(t, ok)
+	assert.Equal(t, "/", ctxPattern)
+
+	ctxMethod, ok := RequestMethodFromContext(rsp.Request.Context)
+	assert.True(t, ok)
+	assert.Equal(t, "GET", ctxMethod)
+}