waitlist-mailer/CHANGELOG.md

Modern, modular TypeScript library for managing waitlists with pluggable storage and mail providers. Supports MongoDB, SQL databases, and custom adapters with zero required dependencies for basic usage.

# Changelog

All notable changes to this project will be documented in this file.

The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

## [2.1.0] - 2025-11-25

### Added

- **Database-level search**: `search()` now delegates filtering to storage providers for optimal performance
  - MongoDB: Uses native `$regex` queries
  - PostgreSQL: Uses `ILIKE` for case-insensitive search
  - MySQL/SQLite: Uses `LIKE` with `LOWER()` function
  - Memory: Optimized in-memory filtering

- **Streaming iterator**: New `iterate(batchSize?)` method on `StorageProvider` interface
  - MongoDB: Uses native Mongoose cursors for memory-efficient streaming
  - SQL: Uses limit/offset pagination
  - Enables processing large datasets without loading everything into memory

- **Search pagination**: `SearchOptions` interface with `limit`, `offset`, and `caseInsensitive` options

- **Safe metadata parsing**: `SequelizeStorage` now validates JSON metadata before parsing
  - Prevents potential injection attacks from malformed JSON
  - Validates parsed result is a plain object

- **New exported type**: `SearchOptions` now exported from main module

- **11 new tests**: Comprehensive tests for search, pagination, and streaming functionality

### Changed

- `WaitlistManager.search()` now accepts optional `SearchOptions` parameter
- `sendBulkEmails()` now uses streaming when available, falling back to legacy mode
- Improved JSDoc documentation for all new methods

### Performance

- `search()` no longer loads entire database into memory
- `sendBulkEmails()` processes entries one at a time using async iterators
- SQL queries properly escape special characters to prevent SQL injection

## [2.0.1] - 2025-11-20

### Fixed

- Minor documentation updates
- TypeScript type exports

## [2.0.0] - 2025-11-20

### Added

- Complete rewrite with clean architecture
- Dependency injection pattern
- Pluggable storage adapters (Memory, Mongoose, Sequelize)
- Pluggable mail adapters (Nodemailer, Console)
- Generic metadata support
- Rich event system
- Zero required dependencies for basic usage
- 33+ comprehensive tests

### Changed

- **BREAKING**: New API - `WaitlistMailer` renamed to `WaitlistManager`
- **BREAKING**: Constructor now accepts configuration object
- **BREAKING**: `addEmail()` renamed to `join()`
- Dependencies moved to peer dependencies

### Removed

- Forced dependencies on database drivers
- Legacy monolithic architecture

## [1.1.0] - 2025-11-15

### Added

- Initial public release
- MongoDB and SQL support
- Basic email sending