More comprehensive tests for HTTP verb endpoints (rakyll#88)

We were not explicitly testing the behavior of some HTTP verb endpoints
like /put and /patch, because they currently share an underlying handler
with /post which is thoroughly tested.

The addition of the /anything endpoint in rakyll#83 made me realize a bit more
explicit test coverage would be good, so here we're landing a bit of a
refactoring of the test suite to generate tests for all of those
endpoints.

Along the way, we also improve compatibility with the original httpbin
implementation by tricking the stdlib net/http machinery into parsing
request bodies for DELETE requests.

httpbin/digest/digest.go

@@ -92,15 +92,15 @@ type authorization struct {
 // parseAuthorizationHeader parses an Authorization header into an
 // Authorization struct, given a an authorization header like:
 //
-//    Authorization: Digest username="Mufasa",
-//                         realm="[email protected]",
-//                         nonce="dcd98b7102dd2f0e8b11d0f600bfb0c093",
-//                         uri="/dir/index.html",
-//                         qop=auth,
-//                         nc=00000001,
-//                         cnonce="0a4f113b",
-//                         response="6629fae49393a05397450978507c4ef1",
-//                         opaque="5ccc069c403ebaf9f0171e9517f40e41"
+//	Authorization: Digest username="Mufasa",
+//	                     realm="[email protected]",
+//	                     nonce="dcd98b7102dd2f0e8b11d0f600bfb0c093",
+//	                     uri="/dir/index.html",
+//	                     qop=auth,
+//	                     nc=00000001,
+//	                     cnonce="0a4f113b",
+//	                     response="6629fae49393a05397450978507c4ef1",
+//	                     opaque="5ccc069c403ebaf9f0171e9517f40e41"
 //
 // If the given value does not contain a Digest authorization header, or is in
 // some other way malformed, nil is returned.
@@ -174,7 +174,7 @@ func hash(data []byte, algorithm digestAlgorithm) string {
 
 // makeHA1 returns the HA1 hash, where
 //
-//     HA1 = H(A1) = H(username:realm:password)
+//	HA1 = H(A1) = H(username:realm:password)
 //
 // and H is one of MD5 or SHA256.
 func makeHA1(realm, username, password string, algorithm digestAlgorithm) string {
@@ -184,7 +184,7 @@ func makeHA1(realm, username, password string, algorithm digestAlgorithm) string
 
 // makeHA2 returns the HA2 hash, where
 //
-//     HA2 = H(A2) = H(method:digestURI)
+//	HA2 = H(A2) = H(method:digestURI)
 //
 // and H is one of MD5 or SHA256.
 func makeHA2(auth *authorization, method, uri string) string {
@@ -195,11 +195,11 @@ func makeHA2(auth *authorization, method, uri string) string {
 // Response calculates the correct digest auth response. If the qop directive's
 // value is "auth" or "auth-int" , then compute the response as
 //
-//    RESPONSE = H(HA1:nonce:nonceCount:clientNonce:qop:HA2)
+//	RESPONSE = H(HA1:nonce:nonceCount:clientNonce:qop:HA2)
 //
 // and if the qop directive is unspecified, then compute the response as
 //
-//    RESPONSE = H(HA1:nonce:HA2)
+//	RESPONSE = H(HA1:nonce:HA2)
 //
 // where H is one of MD5 or SHA256.
 func response(auth *authorization, password, method, uri string) string {

httpbin/handlers.go

@@ -48,7 +48,7 @@ func (h *HTTPBin) UTF8(w http.ResponseWriter, r *http.Request) {
 
 // Get handles HTTP GET requests
 func (h *HTTPBin) Get(w http.ResponseWriter, r *http.Request) {
-	resp := &getResponse{
+	resp := &noBodyResponse{
 		Args:    r.URL.Query(),
 		Headers: getRequestHeaders(r),
 		Origin:  getClientIP(r),
@@ -58,6 +58,16 @@ func (h *HTTPBin) Get(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, body, http.StatusOK)
 }
 
+// Anything returns anything that is passed to request.
+func (h *HTTPBin) Anything(w http.ResponseWriter, r *http.Request) {
+	switch r.Method {
+	case "GET", "HEAD":
+		h.Get(w, r)
+	default:
+		h.RequestWithBody(w, r)
+	}
+}
+
 // RequestWithBody handles POST, PUT, and PATCH requests
 func (h *HTTPBin) RequestWithBody(w http.ResponseWriter, r *http.Request) {
 	resp := &bodyResponse{
@@ -712,7 +722,7 @@ func (h *HTTPBin) ETag(w http.ResponseWriter, r *http.Request) {
 
 	// TODO: This mostly duplicates the work of Get() above, should this be
 	// pulled into a little helper?
-	resp := &getResponse{
+	resp := &noBodyResponse{
 		Args:    r.URL.Query(),
 		Headers: getRequestHeaders(r),
 		Origin:  getClientIP(r),