print headers logs in httpun requests

Author: maxtori

src/request/unix/httpun/httpun_client.ml

@@ -115,6 +115,9 @@ let perform ?msg ?meth ?content ?content_type ?(headers=[]) ?timeout handler url
     | _, None -> `GET
     | _ -> `POST in
   log ~meth:(Method.to_string meth) url msg;
+  (if !Verbose.v land 4 <> 0 then
+     Format.printf "[ez_api] headers\n  %s@." @@
+     String.concat "\n  " @@ List.map (fun (k, v) -> k ^ " : " ^ v) headers);
   (match !Verbose.v land 2 <> 0, content with
    | true, Some content when content <> "" -> Format.printf "[ez_api] sent:\n%s@." content;
    | _ -> ());

src/request/verbose.ml

@@ -12,7 +12,7 @@
   verbose binary flag
   1: string received over http
   2: string sent over http
-  4: library logs
+  4: library logs or headers
 *)
 
 let v = match Sys.getenv_opt "EZAPICLIENT" with