jsonschema: support definitions as an alias for $defs

lib/generator.ml

@@ -19,19 +19,23 @@ let get_ref_name ref =
   (* OpenAPI defs *)
   | [ "#"; "components"; "schemas"; type_name ] -> type_name
   (* JSON Schema defs *)
-  | [ "#"; "$defs"; type_name ] -> type_name
+  | [ "#"; ("$defs" | "definitions"); type_name ] -> type_name
   | _ ->
     failwith
-      (Printf.sprintf "Unsupported ref value: %s. Supported ref URI are: #/components/schemas/* and #/$defs/*" ref)
+      (Printf.sprintf
+         "Unsupported ref value: %s. Supported ref URI are: #/components/schemas/* and #/$defs/* and #/definitions/*"
+         ref
+      )
 
 let output = Buffer.create 16
 let input_toplevel_schemas = ref []
 
 let get_schema_by_ref ~schema ref =
   let defs =
-    match schema.defs with
-    | None -> !input_toplevel_schemas
-    | Some defs -> defs @ !input_toplevel_schemas
+    let defs = List.concat [ Utils.list_of_nonempty schema.defs; Utils.list_of_nonempty schema.definitions ] in
+    match defs with
+    | [] -> !input_toplevel_schemas
+    | defs -> defs @ !input_toplevel_schemas
   in
   List.find_map
     (function
@@ -107,6 +111,7 @@ let merge_all_of schema =
       dependent_required = merge_lists (fun schema -> schema.dependent_required);
       format = take_first_opt (fun schema -> schema.format);
       defs = merge_opt_lists (fun schema -> schema.defs);
+      definitions = merge_opt_lists (fun schema -> schema.definitions);
       title = take_first_opt (fun schema -> schema.title);
       typ = take_first_opt (fun schema -> schema.typ);
       description = take_first_opt (fun schema -> schema.description);
@@ -222,9 +227,10 @@ let make_atd_of_jsonschema input =
   let schema = Json_schema_j.schema_of_string input in
   let root_type_name = Option.value ~default:"root" schema.title in
   let defs =
-    match schema.defs with
-    | None -> []
-    | Some defs -> List.map (fun (name, schema) -> name, Obj schema) defs
+    let defs = List.concat [ Utils.list_of_nonempty schema.defs; Utils.list_of_nonempty schema.definitions ] in
+    match defs with
+    | [] -> []
+    | defs -> List.map (fun (name, schema) -> name, Obj schema) defs
   in
   make_atd_of_schemas ([ root_type_name, Obj schema ] @ defs)
 

lib/json_schema.atd

@@ -88,6 +88,7 @@ type schema = {
 
   (* 8.2.4. re-usable JSON Schemas *)
   ~defs <json name="$defs">: (string * schema) list <json repr="object"> nullable;
+  ~definitions: (string * schema) list <json repr="object"> nullable;
 
   (* 9. basic metadata annotations *)
   ~title : string nullable;

lib/utils.ml

@@ -98,3 +98,7 @@ let shortest_list lists = lists |> List.sort (fun a b -> compare (List.length a)
 let nonempty_list_opt = function
   | [] -> None
   | non_empty_list -> Some non_empty_list
+
+let list_of_nonempty = function
+  | None -> []
+  | Some l -> l

tests/mocks/jsonchema_definitions.json

@@ -0,0 +1,23 @@
+{
+  "$id": "https://example.com/schemas/customer",
+  "type": "object",
+  "properties": {
+    "first_name": {
+      "$ref": "#/$defs/name"
+    },
+    "last_name": {
+      "$ref": "#/definitions/name"
+    }
+  },
+  "required": [
+    "first_name",
+    "last_name",
+    "shipping_address",
+    "billing_address"
+  ],
+  "definitions": {
+    "name": {
+      "type": "string"
+    }
+  }
+}

tests/smoke.t

@@ -56,3 +56,16 @@ Generate ATD out of JSON Schema that contains defs
     first_name: name;
     last_name: name;
   }
+
+Generate ATD out of JSON Schema that contains definitions (legacy support)
+  $ jsonschema2atd --format=jsonschema ./mocks/jsonchema_definitions.json
+  (* Generated by jsonschema2atd *)
+  type json <ocaml module="Yojson.Basic" t="t"> = abstract
+  type int64 = int <ocaml repr="int64">
+
+  type name = string
+
+  type root = {
+    first_name: name;
+    last_name: name;
+  }