refactor: wip

Author: BioPhoton

packages/utils/src/lib/wal.ts

@@ -290,7 +290,9 @@ export const stringCodec = <
  *  - walExtension defaults to '.log'
  *  - finalExtension defaults to '.log'
  *  - codec defaults to stringCodec<T>()
- *  - finalizer defaults to (encodedRecords: (T | InvalidEntry<string>)[]) => `${encodedRecords.join('\n')}\n`
+ *  - finalizer defaults to encoding each record using codec.encode() and joining with newlines.
+ *    For object types, this properly JSON-stringifies them (not [object Object]).
+ *    InvalidEntry records use their raw string value directly.
  * @param format - Partial WalFormat configuration
  * @returns Parsed WalFormat with defaults filled in
  */
@@ -306,8 +308,11 @@ export function parseWalFormat<T extends object | string = object>(
 
   const finalizer =
     format.finalizer ??
-    ((encodedRecords: (T | InvalidEntry<string>)[]) => {
-      const encoded = encodedRecords.map(record =>
+    ((records: (T | InvalidEntry<string>)[]) => {
+      // Encode each record using the codec before joining.
+      // For object types, codec.encode() will JSON-stringify them properly.
+      // InvalidEntry records use their raw string value directly.
+      const encoded = records.map(record =>
         typeof record === 'object' && record != null && '__invalid' in record
           ? (record as InvalidEntry<string>).raw
           : codec.encode(record as T),

packages/utils/src/lib/wal.unit.test.ts

@@ -662,6 +662,19 @@ describe('parseWalFormat', () => {
     const output = result.finalizer(records);
     expect(output).toBe('valid\ninvalid-raw\nalso-valid\n');
   });
+
+  it('should encode objects correctly when using default type parameter', () => {
+    // Test parseWalFormat({}) with default type parameter (object)
+    const result = parseWalFormat({});
+    const records = [
+      { id: 1, name: 'test1' },
+      { id: 2, name: 'test2' },
+    ];
+    const output = result.finalizer(records);
+    // Should be JSON strings, not [object Object]
+    expect(output).toBe('{"id":1,"name":"test1"}\n{"id":2,"name":"test2"}\n');
+    expect(output).not.toContain('[object Object]');
+  });
 });
 
 describe('isLeaderWal', () => {