add tests and run linter

Author: Vizonex

test/fixtures/extra.c

@@ -201,6 +201,12 @@ void llhttp__test_init_response_lenient_header_value_relaxed(llparse_t* s) {
   s->lenient_flags |= LENIENT_HEADER_VALUE_RELAXED;
 }
 
+void llhttp__test_init_request_lenient_host_header_relaxed(llparse_t* s) {
+  llhttp__test_init_request(s);
+  s->lenient_flags |= LENIENT_HOST_HEADER;
+}
+
+
 
 void llhttp__test_finish(llparse_t* s) {
   llparse__print(NULL, NULL, "finish=%d", s->finish);

test/request/lenitent-host-header.md

@@ -0,0 +1,31 @@
+Relaxed host header
+===================
+
+Relaxed host header mode: accepts multiple host headers
+this is meant to stop redirection or injection attacks 
+and other unusual behaviors.
+
+## multiple host headers (relaxed)
+HOST_HEADER if set should allow multiple hosts to be set.
+
+<!-- meta={"type": "request_lenient_host_header_relaxed"} -->
+
+```http
+GET /url HTTP/1.1
+host: www.python.org
+host: llhttp.org
+
+```
+
+
+## Multiple Host
+
+HOST_HEADER if disabled should not allow multiple headers to be set.
+
+```http
+GET /url HTTP/1.1
+host: www.python.org
+host: llhttp.org
+
+```
+