feat(smartjson): Add JSONL stringify and ordering comparator; fix empty buffer handling; refactor Smartjson folding/enfolding

test/test.both.ts

@@ -72,4 +72,36 @@ tap.test('should work with buffers', async () => {
   expect(text).toEqual('hello');
 });
 
+tap.test('should handle empty buffers', async () => {
+  const someObject = { empty: new Uint8Array([]) };
+  const json = smartjson.stringify(someObject);
+  const parsed = smartjson.parse(json);
+  expect(parsed.empty).toBeInstanceOf(Uint8Array);
+  expect(parsed.empty.length).toEqual(0);
+});
+
+tap.test('should parse and stringify JSONL', async () => {
+  const items = [
+    { id: 1, name: 'a' },
+    { id: 2, name: 'b' }
+  ];
+  const jsonl = smartjson.stringifyJsonL(items);
+  const parsed = smartjson.parseJsonL(jsonl);
+  expect(parsed).toEqual(items);
+});
+
+tap.test('should deep-compare JSONL strings', async () => {
+  const a = '{"id":2,"name":"b"}\n{"id":1,"name":"a"}';
+  const b = '{"id":2,"name":"b"}\n{"id":1,"name":"a"}';
+  expect(smartjson.deepEqualJsonLStrings(a, b)).toEqual(true);
+});
+
+tap.test('should respect simpleOrderArray comparator', async () => {
+  const obj = { c: 3, a: 1, b: 2 };
+  const ordered = smartjson.stringify(obj, ['b', 'a']);
+  // ensure keys b, a come before c
+  expect(ordered.indexOf('"b"')).toBeLessThan(ordered.indexOf('"a"'));
+  expect(ordered.indexOf('"a"')).toBeLessThan(ordered.indexOf('"c"'));
+});
+
 tap.start();