Recipient Resolver

Small, zero-magic library to resolve named recipient lists (e.g. alerts, billing) into a structured Recipient object with To / CC / BCC. Simple YAML config in, objects out. Works great in PHP apps and can be wrapped for CLI/other languages.

Why?

• Centralize who gets which emails (alerts, ops, marketing, …)
• Keep config in version control (YAML)
• Resolve lists reliably in code (alerts → Recipient(to: ["alerts@example.com"]))

Features

• ✅ Tiny API: all() and resolve($list)
• ✅ YAML provider included
• ✅ Recipient value object (TO/CC/BCC) + NullRecipient fallback
• ✅ JSON-serializable recipients
• ✅ Framework-agnostic, strict types
• 🔌 Extensible via RecipientProviderInterface

Install

composer require ucarsolutions/recipient-resolver

Usage

1) YAML config (with TO/CC/BCC)

# recipients.yaml
alerts:
  receiver:
    - alerts@example.com
  cc:
    - cc.alerts@example.com
  bcc: []

billing:
  receiver:
    - billing@example.com
    - finance@example.com
  cc: []
  bcc:
    - billing.bcc@example.com

marketing-de:
  receiver:
    - de.marketing@example.com

Schema: Each top-level key is a list name. Under it, use arrays receiver, cc, and bcc. Missing keys are treated as empty lists. Invalid emails are skipped.

2) PHP

<?php
use Ucarsolutions\RecipientResolver\Provider\YamlRecipientProvider;
use Ucarsolutions\RecipientResolver\Service\RecipientResolver;
use Ucarsolutions\RecipientResolver\Entity\Recipient;
use Ucarsolutions\RecipientResolver\Entity\NullRecipient;

$provider = new YamlRecipientProvider(__DIR__ . '/recipients.yaml');
$resolver = new RecipientResolver($provider);

// Get the whole map
/** @var array<string, Recipient> $all */
$all = $resolver->all();

// Resolve a single list
$alerts = $resolver->resolve('alerts'); // Recipient

$to  = $alerts->getReceiver();        // ['alerts@example.com']
$cc  = $alerts->getCarbonCopy();      // ['cc.alerts@example.com']
$bcc = $alerts->getBlindCarbonCopy(); // []

// Unknown list → NullRecipient (safe no-op)
$unknown = $resolver->resolve('does-not-exist'); // NullRecipient
$unknown->getReceiver(); // []

// JSON (e.g., for logging)
$json = json_encode($alerts, JSON_THROW_ON_ERROR);
// {"recipient":["alerts@example.com"],"carbonCopy":["cc.alerts@example.com"],"blindCarbonCopy":[]}

Extensibility

Implement your own source by plugging into the interface:

<?php
use Ucarsolutions\RecipientResolver\Entity\Recipient;
use Ucarsolutions\RecipientResolver\Provider\RecipientProviderInterface;

/**
 * @return array<string, Recipient>
 */
final class MyDbRecipientProvider implements RecipientProviderInterface
{
    public function provide(): array
    {
        // Build Recipient objects from your data source
        return [
            'alerts' => new Recipient(
                receiver: ['a@example.com'],
                carbonCopy: [],
                blindCarbonCopy: [],
            ),
        ];
    }
}

Then wire it:

<?php
use Ucarsolutions\RecipientResolver\Service\RecipientResolver;

$resolver = new RecipientResolver(new MyDbRecipientProvider());

Behavior & Guarantees

• Validation: Emails are validated with filter_var(..., FILTER_VALIDATE_EMAIL). Invalid entries are skipped.
• Empties: Missing sections (receiver/cc/bcc) → treated as empty arrays.
• Duplicates: Preserved (provider does not deduplicate).
• Unknown lists: resolve() returns NullRecipient (all arrays empty).

Testing

This repo ships with PHPUnit tests using real files/classes (no mocks).

composer install
vendor/bin/phpunit

Roadmap help welcome!

• Optional de-duplication per list
• Optional “merge providers” (e.g., base YAML + env override)
• Optional CLI wrapper to print JSON/CSV/lines

Contributing

Issues and PRs are very welcome. Keep it small, readable, and covered by tests.
For new providers, add minimal docs + tests.

License

MIT © Ucar Solutions