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

changelog.md

@@ -1,5 +1,15 @@
 # Changelog
 
+## 2025-09-12 - 5.1.0 - feat(smartjson)
+Add JSONL stringify and ordering comparator; fix empty buffer handling; refactor Smartjson folding/enfolding
+
+- Export stringifyJsonL(items: any[]) and add README documentation for JSONL stringification
+- stringify(obj, simpleOrderArray) now derives a stable-json comparator from simpleOrderArray when no custom cmp is provided, ensuring predictable key ordering
+- Fix buffer handling: empty Uint8Array values are preserved (no longer serialized to an empty string) and encoding/decoding logic improved
+- Refactor Smartjson.enfoldFromObject to safely use saveableProperties and avoid repeated property access
+- Simplify Smartjson.foldToObject to delegate to an internal foldToObjectInternal with cycle detection and correct nested instance handling
+- Add unit tests for empty buffers, JSONL parse/stringify, deepEqualJsonLStrings, and simpleOrderArray comparator behavior
+
 ## 2025-09-12 - 5.0.21 - fix(Smartjson)
 Cross-platform buffer/base64 handling, safer folding with cycle detection, parsing fixes, docs and dependency updates
 

readme.md

@@ -99,6 +99,13 @@ const jsonLines = `{"event":"start","time":1234}
 const events = smartjson.parseJsonL(jsonLines);
 // Result: Array of parsed objects
 
+// Produce JSONL from objects
+const jsonlOut = smartjson.stringifyJsonL([
+  { event: 'start', time: 1234 },
+  { event: 'data', value: 42 },
+  { event: 'end', time: 5678 }
+]);
+
 // Compare JSON Lines data
 const jsonL1 = `{"id":1}\n{"id":2}`;
 const jsonL2 = `{"id":1}\n{"id":2}`;
@@ -308,6 +315,7 @@ class AppConfig extends Smartjson {
 - `stringifyBase64(obj: any): string` - Encode JSON as base64
 - `parseBase64(base64String: string): any` - Decode base64 JSON
 - `parseJsonL(jsonLinesString: string): any[]` - Parse JSON Lines format
+- `stringifyJsonL(items: any[]): string` - Stringify array to JSON Lines
 - `deepEqualObjects(obj1: any, obj2: any): boolean` - Deep comparison of objects
 - `deepEqualJsonLStrings(jsonL1: string, jsonL2: string): boolean` - Compare JSON Lines strings
 

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();

ts/00_commitinfo_data.ts

@@ -3,6 +3,6 @@
  */
 export const commitinfo = {
   name: '@push.rocks/smartjson',
-  version: '5.0.21',
+  version: '5.1.0',
   description: 'A library for handling typed JSON data, providing functionalities for parsing, stringifying, and working with JSON objects, including support for encoding and decoding buffers.'
 }

ts/bufferhandling.ts

@@ -52,11 +52,7 @@ const replacer: TParseReplacer = (key, value) => {
 
     // Handle IBufferLike objects with a .data property
     if ('data' in value && isArray(value.data)) {
-      if (value.data.length > 0) {
+      bufferData = new Uint8Array(value.data);
-        bufferData = new Uint8Array(value.data);
-      } else {
-        return ''; // Return empty string for empty data arrays
-      }
     } 
     // Handle Uint8Array directly
     else if (value instanceof Uint8Array) {

ts/index.ts

@@ -22,6 +22,10 @@ export const parseJsonL = (jsonlData: string): JsonObject[] => {
   return parsedData;
 }
 
+export const stringifyJsonL = (items: any[]): string => {
+  return items.map((item) => stringify(item)).join('\n');
+}
+
 /**
  *
  * @param objArg
@@ -34,7 +38,20 @@ export const stringify = (
 ): string => {
   const bufferedJson = bufferhandling.stringify(objArg);
   objArg = JSON.parse(bufferedJson);
-  let returnJson = plugins.stableJson(objArg, optionsArg);
+  // derive a simple comparator from simpleOrderArray if provided and no custom cmp supplied
+  let options = { ...optionsArg };
+  if (simpleOrderArray && !options.cmp) {
+    const order = new Map<string, number>();
+    simpleOrderArray.forEach((key, idx) => order.set(key, idx));
+    options.cmp = (a, b) => {
+      const aIdx = order.has(a.key) ? (order.get(a.key) as number) : Number.POSITIVE_INFINITY;
+      const bIdx = order.has(b.key) ? (order.get(b.key) as number) : Number.POSITIVE_INFINITY;
+      if (aIdx !== bIdx) return aIdx - bIdx;
+      // fallback to lexicographic order for stable behavior
+      return a.key < b.key ? -1 : a.key > b.key ? 1 : 0;
+    };
+  }
+  let returnJson = plugins.stableJson(objArg, options);
   return returnJson;
 };
 
@@ -62,9 +79,10 @@ export class Smartjson {
    */
   public static enfoldFromObject<T extends typeof Smartjson>(this: T, objectArg: any): InstanceType<T> {
     const newInstance = new this() as InstanceType<T>;
+    const saveables: string[] = (newInstance as any).saveableProperties || [];
     for (const keyName in objectArg) {
-      if (newInstance.saveableProperties.indexOf(keyName) !== -1) {
+      if (saveables.indexOf(keyName) !== -1) {
-        newInstance[keyName] = objectArg[keyName];
+        (newInstance as any)[keyName] = objectArg[keyName];
       }
     }
     return newInstance;
@@ -88,26 +106,9 @@ export class Smartjson {
    * folds a class into an object
    */
   public foldToObject() {
-    const newFoldedObject: { [key: string]: any } = {};
     const trackSet = new Set<Smartjson>();
-    const foldValue = (val: any): any => {
+    trackSet.add(this);
-      if (val instanceof Smartjson) {
+    return this.foldToObjectInternal(trackSet);
-        if (trackSet.has(val)) {
-          throw new Error('cycle detected');
-        }
-        trackSet.add(val);
-        return val.foldToObjectInternal(trackSet);
-      }
-      if (Array.isArray(val)) {
-        return val.map((item) => foldValue(item));
-      }
-      return plugins.lodashCloneDeep(val);
-    };
-    for (const keyName of this.saveableProperties) {
-      const value = this[keyName];
-      newFoldedObject[keyName] = foldValue(value);
-    }
-    return newFoldedObject;
   }
 
   private foldToObjectInternal(trackSet: Set<Smartjson>) {
@@ -125,7 +126,8 @@ export class Smartjson {
       }
       return plugins.lodashCloneDeep(val);
     };
-    for (const keyName of this.saveableProperties) {
+    const props: string[] = (this as any).saveableProperties || [];
+    for (const keyName of props) {
       const value = this[keyName];
       result[keyName] = foldValue(value);
     }