From a428916e01013235601cb2026ddad3f8ca2e1e9d Mon Sep 17 00:00:00 2001
From: Egor Chemokhonenko <egor.chemohonenko@ahrefs.com>
Date: Fri, 29 Dec 2023 01:19:50 +0200
Subject: [PATCH] Merge properties and required fields in allOf composition

---
 lib/generator.ml    | 32 ++++++++++++++++++++++++++++++--
 lib/json_schema.atd |  2 +-
 tests/all_of.ml     | 45 +++++++++++++++++++++++----------------------
 tests/dune          |  1 +
 4 files changed, 55 insertions(+), 25 deletions(-)

diff --git a/lib/generator.ml b/lib/generator.ml
index ee93f7c..f2b8c5b 100644
--- a/lib/generator.ml
+++ b/lib/generator.ml
@@ -15,7 +15,7 @@ let process_int_type schema =
   | _ -> failwith "int has unextected format"
 
 let get_ref (ref : ref_) =
-  match ref |> String.split_on_char '/' |> List.rev  with
+  match ref |> String.split_on_char '/' |> List.rev with
   | type_name :: _ -> type_name
   | _ -> failwith (Printf.sprintf "%s: can't resolve ref type name" ref)
 
@@ -36,7 +36,32 @@ let make_atd_default_value enum json_value =
 
 let nullable = Printf.sprintf "%s nullable"
 
+let nonempty_list_opt = function
+  | [] -> None
+  | non_empty_list -> Some non_empty_list
+
+let rec merge_all_of schema =
+  match schema.all_of with
+  | None -> schema
+  | Some [] -> failwith "empty allOf is unexpected"
+  | Some schemas ->
+    let all_schemas =
+      schema
+      :: List.filter_map
+           (function
+             | Obj schema -> Some (merge_all_of schema)
+             | Ref _ -> None
+             )
+           schemas
+    in
+    {
+      schema with
+      properties = all_schemas |> List.filter_map (fun schema -> schema.properties) |> List.flatten |> nonempty_list_opt;
+      required = all_schemas |> List.map (fun schema -> schema.required) |> List.flatten;
+    }
+
 let rec process_schema_type ~ancestors (schema : schema) =
+  let schema = merge_all_of schema in
   let maybe_nullable type_ = if schema.nullable then nullable type_ else type_ in
   match schema.one_of with
   | Some schemas -> process_one_of ~ancestors schemas
@@ -134,6 +159,7 @@ type int64 = int <ocaml repr="int64">
 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
+  Buffer.clear toplevel_definitions;
   base ^ "\n" ^ process_schemas [ root_type_name, Obj schema ]
 
 let make_atd_of_openapi input =
@@ -142,5 +168,7 @@ let make_atd_of_openapi input =
   | None -> failwith "components are empty"
   | Some components ->
   match components.schemas with
-  | Some schemas -> base ^ "\n" ^ process_schemas schemas
+  | Some schemas ->
+    Buffer.clear toplevel_definitions;
+    base ^ "\n" ^ process_schemas schemas
   | None -> failwith "components schemas are empty"
diff --git a/lib/json_schema.atd b/lib/json_schema.atd
index 2ec3cb7..8001e2a 100644
--- a/lib/json_schema.atd
+++ b/lib/json_schema.atd
@@ -40,7 +40,7 @@ type schema = {
   ~schema <json name="$schema">: string nullable;
 
   (* 10.2.1 keywords for applying subschemas with logic *)
-  ~all_of <json name="allOf">: schema nonempty_list nullable;
+  ~all_of <json name="allOf">: schema or_ref nonempty_list nullable;
   ~any_of <json name="anyOf">: schema nonempty_list nullable;
   ~one_of <json name="oneOf">: schema or_ref nonempty_list nullable;
   ~not : schema nullable;
diff --git a/tests/all_of.ml b/tests/all_of.ml
index 5978e35..2e73d68 100644
--- a/tests/all_of.ml
+++ b/tests/all_of.ml
@@ -5,32 +5,32 @@ let simple_test _ =
   let input =
     {| {
     "dummy": {
-      "type": "object",
-      "properties": {
-        "field": {
-          "id": "string"
-        }
-      },
-      "allOf": [
-        {
-          "type": "object",
-          "properties": {
-            "field": {
-              "name": "string"
+        "type": "object",
+        "properties": {
+            "id": {
+                "type": "string"
             }
-          }
         },
-        {
-          "type": "object",
-          "properties": {
-            "field": {
-              "surname": "string"
+        "allOf": [
+            {
+                "type": "object",
+                "properties": {
+                    "name": {
+                        "type": "string"
+                    }
+                }
+            },
+            {
+                "type": "object",
+                "properties": {
+                    "surname": {
+                        "type": "string"
+                    }
+                }
             }
-          }
-        }
-      ]
+        ]
     }
-}|}
+} |}
   in
   let output =
     {|
@@ -38,6 +38,7 @@ let simple_test _ =
       ?id: string option;
       ?name: string option;
       ?surname: string option;
+     }
   |}
   in
   assert_schema input output
diff --git a/tests/dune b/tests/dune
index f01de6e..b1f1878 100644
--- a/tests/dune
+++ b/tests/dune
@@ -1,5 +1,6 @@
 (tests
  (names
+  all_of
   base
   defaults
   enums