ewjin 2042a29877 test(shared): add unit tests for deep-merge utility
Add comprehensive unit tests for the deep-merge.ts utility functions:

- isPlainObject: 11 test cases covering null, undefined, primitives,
  Array, Date, RegExp, and plain objects
- deepMerge: 15 test cases covering:
  - Basic object merging
  - Deep nested object merging
  - Edge cases (undefined handling)
  - Array replacement behavior
  - Prototype pollution protection (DANGEROUS_KEYS)
  - MAX_DEPTH limit handling
2026-01-13 22:23:11 +09:00
..