Normalize an empty path

handler_test.go

@@ -39,13 +39,13 @@ func Test_WrapHandler(t *testing.T) {
 	defer ts.Close()
 
 	signer, err := NewHMACSHA256Signer("key", bytes.Repeat([]byte{1}, 64), nil,
-		Headers("@method", "content-digest"))
+		Headers("@method", "content-digest", "@request-target"))
 	assert.NoError(t, err)
 
 	verifier, err := NewHMACSHA256Verifier("key", bytes.Repeat([]byte{0}, 64), NewVerifyConfig(), *NewFields())
 	assert.NoError(t, err)
 	client := NewDefaultClient(NewClientConfig().SetSignatureName("sig1").SetSigner(signer).SetVerifier(verifier).SetDigestSchemesSend([]string{DigestSha256}))
-	res, err := client.Post(ts.URL, "text/plain", strings.NewReader("Message body here"))
+	res, err := client.Post(ts.URL+"?foo", "text/plain", strings.NewReader("Message body here"))
 	assert.NoError(t, err)
 	if res != nil {
 		_, err = io.ReadAll(res.Body)

httpparse.go

@@ -145,10 +145,14 @@ func scQuery(url *url.URL) string {
 }
 
 func scRequestTarget(url *url.URL) string {
+	path := url.Path
+	if path == "" {
+		path = "/" // Normalize path, issue #8, and see https://www.rfc-editor.org/rfc/rfc9110#section-4.2.3
+	}
 	if url.RawQuery == "" {
-		return url.Path
+		return path
 	}
-	return url.Path + "?" + url.RawQuery
+	return path + "?" + url.RawQuery
 }
 
 func scScheme(url *url.URL) string {