From a60573383784d331a6c1ed9f77aea06cc6ec881a Mon Sep 17 00:00:00 2001
From: yehonatanz <yonti95@gmail.com>
Date: Sat, 27 Jan 2024 17:55:01 +0200
Subject: [PATCH] Support optional fields using IDL question mark syntax (#446)

---
 lib/specs.js       |  4 ++++
 test/test_specs.js | 24 ++++++++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/lib/specs.js b/lib/specs.js
index 88c75189..07321ad9 100644
--- a/lib/specs.js
+++ b/lib/specs.js
@@ -427,11 +427,15 @@ class Reader {
     if (javadoc !== undefined && schema.doc === undefined) {
       schema.doc = javadoc;
     }
+    const isOptional = tk.next({id: 'operator', val: '?', silent: true});
     this._readAnnotations(schema);
     schema.name = tk.next({id: 'name'}).val;
     if (tk.next({val: '=', silent: true})) {
       schema['default'] = tk.next({id: 'json'}).val;
     }
+    if (isOptional) {
+      schema.type = 'default' in schema && schema.default !== null ? [schema.type, 'null'] : ['null', schema.type];
+    }
     return schema;
   }
 
diff --git a/test/test_specs.js b/test/test_specs.js
index 1ee95708..2895f2ee 100644
--- a/test/test_specs.js
+++ b/test/test_specs.js
@@ -737,6 +737,30 @@ suite('specs', () => {
       );
     });
 
+    test('optional field no default value', () => {
+      const usingQuestionMark = readSchema('record { int? optionalInt; }');
+      const usingUnion = readSchema('record { union{null,int} optionalInt; }');
+      assert.deepEqual(usingQuestionMark, usingUnion);
+    });
+
+    test('optional field null default value', () => {
+      const usingQuestionMark = readSchema('record { int? optionalInt = null; }');
+      const usingUnion = readSchema('record { union{null,int} optionalInt = null; }');
+      assert.deepEqual(usingQuestionMark, usingUnion);
+    });
+
+    test('optional field non-null default value', () => {
+      const usingQuestionMark = readSchema('record { int? optionalInt = 0; }');
+      const usingUnion = readSchema('record { union{int,null} optionalInt = 0; }');
+      assert.deepEqual(usingQuestionMark, usingUnion);
+    });
+
+    test('optional field with annotations', () => {
+      const usingQuestionMark = readSchema('record { int? @order("ascending") optionalInt = 0; }');
+      const usingUnion = readSchema('record { union{int,null} @order("ascending") optionalInt = 0; }');
+      assert.deepEqual(usingQuestionMark, usingUnion);
+    });
+
   });
 
   suite('readProtocol', () => {