Render JSON sink output with yojson

dune-project

@@ -22,6 +22,7 @@
  (depends
   (ocaml (>= 4.14))
   (dune (>= 3.23))
+  yojson
   (alcotest :with-test))
  (tags
   ("logging" "structured-logging" "json" "library")))

lib/sinks/dune

@@ -1,4 +1,4 @@
 (library
  (name scribe_sinks)
  (public_name scribe.sinks)
- (libraries scribe))
+ (libraries scribe yojson))

lib/sinks/json.ml

@@ -1,51 +1,20 @@
-let add_json_string buffer value =
-  Buffer.add_char buffer '"';
-  String.iter
-    (fun char ->
-       match char with
-       | '"' -> Buffer.add_string buffer "\\\""
-       | '\\' -> Buffer.add_string buffer "\\\\"
-       | '\b' -> Buffer.add_string buffer "\\b"
-       | '\012' -> Buffer.add_string buffer "\\f"
-       | '\n' -> Buffer.add_string buffer "\\n"
-       | '\r' -> Buffer.add_string buffer "\\r"
-       | '\t' -> Buffer.add_string buffer "\\t"
-       | char when Char.code char < 0x20 ->
-         Buffer.add_string buffer (Printf.sprintf "\\u%04x" (Char.code char))
-       | char -> Buffer.add_char buffer char)
-    value;
-  Buffer.add_char buffer '"'
+let json_of_value = function
+  | Scribe.Field.String value -> `String value
+  | Scribe.Field.Int value -> `Int value
+  | Scribe.Field.Bool value -> `Bool value
 ;;
 
-let add_value buffer = function
-  | Scribe.Field.String value -> add_json_string buffer value
-  | Scribe.Field.Int value -> Buffer.add_string buffer (string_of_int value)
-  | Scribe.Field.Bool value -> Buffer.add_string buffer (string_of_bool value)
-;;
+let json_of_field field = Scribe.Field.key field, json_of_value (Scribe.Field.value field)
 
-let add_fields buffer fields =
-  Buffer.add_char buffer '{';
-  List.iteri
-    (fun index field ->
-       if index > 0 then Buffer.add_char buffer ',';
-       add_json_string buffer (Scribe.Field.key field);
-       Buffer.add_char buffer ':';
-       add_value buffer (Scribe.Field.value field))
-    fields;
-  Buffer.add_char buffer '}'
+let json_of_event event =
+  `Assoc
+    [ "level", `String (Scribe.Level.to_string (Scribe.Event.level event))
+    ; "message", `String (Scribe.Event.message event)
+    ; "fields", `Assoc (List.map json_of_field (Scribe.Event.fields event))
+    ]
 ;;
 
-let string_of_event event =
-  let buffer = Buffer.create 128 in
-  Buffer.add_string buffer "{\"level\":";
-  add_json_string buffer (Scribe.Level.to_string (Scribe.Event.level event));
-  Buffer.add_string buffer ",\"message\":";
-  add_json_string buffer (Scribe.Event.message event);
-  Buffer.add_string buffer ",\"fields\":";
-  add_fields buffer (Scribe.Event.fields event);
-  Buffer.add_char buffer '}';
-  Buffer.contents buffer
-;;
+let string_of_event event = Yojson.Safe.to_string (json_of_event event)
 
 let channel output =
   Scribe.Sink.make (fun event ->

scribe.opam

@@ -13,6 +13,7 @@ bug-reports: "https://github.com/sambyeol/scribe/issues"
 depends: [
   "ocaml" {>= "4.14"}
   "dune" {>= "3.23"}
+  "yojson"
   "alcotest" {with-test}
   "odoc" {with-doc}
 ]