From 2a4d1cab8e31b20ab8a3f41b4dce2cd51ce0fb8a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Louis=20Roch=C3=A9?= <louis@louisroche.net>
Date: Tue, 27 Feb 2024 16:11:22 +0100
Subject: [PATCH] TMP jsonschema: support external references

---
 lib/generator.ml                 | 27 +++++++++++++-------
 tests/mocks/jsonschema_refs.json | 42 ++++++++++++++++++++++++++++++++
 tests/smoke.t                    | 19 +++++++++++++++
 3 files changed, 79 insertions(+), 9 deletions(-)
 create mode 100644 tests/mocks/jsonschema_refs.json

diff --git a/lib/generator.ml b/lib/generator.ml
index 3b7c37c..773c599 100644
--- a/lib/generator.ml
+++ b/lib/generator.ml
@@ -23,17 +23,26 @@ let process_int_type schema =
   | _ -> failwith "int has unextected format"
 
 let get_ref_name ref =
-  match String.split_on_char '/' ref with
+  let uri, pointer =
+    match String.split_on_char '#' ref with
+    | [ uri; pointer ] -> uri, Some pointer
+    | [ uri ] -> uri, None
+    | _ -> failwith (sprintf "Unsupported remote ref value: %s. The URI contains multiple '#'." ref)
+  in
+  let name_of_path path =
+    match path |> String.split_on_char '/' |> List.rev |> List.hd with
+    | exception _ -> failwith (sprintf "Unsupported ref value: %s" ref)
+    | name -> name
+  in
+  match pointer with
+  | None -> name_of_path uri
+  | Some pointer ->
+  match String.split_on_char '/' pointer with
   (* OpenAPI defs *)
-  | [ "#"; "components"; "schemas"; type_name ] -> type_name
+  | [ ""; "components"; "schemas"; type_name ] -> type_name
   (* JSON Schema defs *)
-  | [ "#"; ("$defs" | "definitions"); type_name ] -> type_name
-  | _ ->
-    failwith
-      (Printf.sprintf
-         "Unsupported ref value: %s. Supported ref URI are: #/components/schemas/* and #/$defs/* and #/definitions/*"
-         ref
-      )
+  | [ ""; ("$defs" | "definitions"); type_name ] -> type_name
+  | _ -> name_of_path pointer
 
 let output = Buffer.create 16
 let input_toplevel_schemas = ref []
diff --git a/tests/mocks/jsonschema_refs.json b/tests/mocks/jsonschema_refs.json
new file mode 100644
index 0000000..de2045d
--- /dev/null
+++ b/tests/mocks/jsonschema_refs.json
@@ -0,0 +1,42 @@
+{
+  "$id": "https://example.com/schemas/customer",
+  "type": "object",
+  "properties": {
+    "first_name": {
+      "type": "string"
+    },
+    "last_name": {
+      "type": "string"
+    },
+    "shipping_address": {
+      "$ref": "/schemas/address"
+    },
+    "billing_address": {
+      "$ref": "/schemas/address"
+    },
+    "aa": {
+      "$ref": "https://example.com/schemas/address"
+    },
+    "bb": {
+      "$ref": "http://example.com/schemas/address"
+    },
+    "cc": {
+      "$ref": "http://example.com/schemas#/definitions/address"
+    },
+    "dd": {
+      "$ref": "http://example.com/schemas#/definitions/address"
+    },
+    "ee": {
+      "$ref": "#/definitions/schemas/address"
+    },
+    "ff": {
+      "$ref": "#/definitions/address"
+    }
+  },
+  "required": [
+    "first_name",
+    "last_name",
+    "shipping_address",
+    "billing_address"
+  ]
+}
diff --git a/tests/smoke.t b/tests/smoke.t
index 00a6e90..2b60b36 100644
--- a/tests/smoke.t
+++ b/tests/smoke.t
@@ -69,3 +69,22 @@ Generate ATD out of JSON Schema that contains definitions (legacy support)
     first_name : name;
     last_name : name;
   } 
+
+Generate ATD out of JSON Schema that uses references
+  $ jsonschema2atd --format=jsonschema ./mocks/jsonschema_refs.json
+  (* Generated by jsonschema2atd *)
+  type json <ocaml module="Yojson.Basic" t="t"> = abstract
+  type int64 = int <ocaml repr="int64">
+  
+  type root = {
+    first_name : string;
+    last_name : string;
+    shipping_address : address;
+    billing_address : address;
+    ?aa : address option;
+    ?bb : address option;
+    ?cc : address option;
+    ?dd : address option;
+    ?ee : address option;
+    ?ff : address option;
+  }