B2B-88: add starter kit structure and elements

packages/mailers/core/src/index.ts

@@ -0,0 +1,12 @@
+import { MAILER_PROVIDER } from './provider-enum';
+import { mailerRegistry } from './registry';
+
+/**
+ * @name getMailer
+ * @description Get the mailer based on the environment variable using the registry internally.
+ */
+export function getMailer() {
+  return mailerRegistry.get(MAILER_PROVIDER);
+}
+
+export { MAILER_PROVIDER };

packages/mailers/core/src/provider-enum.ts

@@ -0,0 +1,16 @@
+import { z } from 'zod';
+
+const MAILER_PROVIDERS = [
+  'nodemailer',
+  'resend',
+  // add more providers here
+] as const;
+
+const MAILER_PROVIDER = z
+  .enum(MAILER_PROVIDERS)
+  .default('nodemailer')
+  .parse(process.env.MAILER_PROVIDER);
+
+export { MAILER_PROVIDER };
+
+export type MailerProvider = (typeof MAILER_PROVIDERS)[number];

packages/mailers/core/src/registry.ts

@@ -0,0 +1,26 @@
+import { Mailer } from '@kit/mailers-shared';
+import { createRegistry } from '@kit/shared/registry';
+
+import { MailerProvider } from './provider-enum';
+
+const mailerRegistry = createRegistry<Mailer, MailerProvider>();
+
+mailerRegistry.register('nodemailer', async () => {
+  if (process.env.NEXT_RUNTIME === 'nodejs') {
+    const { createNodemailerService } = await import('@kit/nodemailer');
+
+    return createNodemailerService();
+  } else {
+    throw new Error(
+      'Nodemailer is not available on the edge runtime. Please use another mailer.',
+    );
+  }
+});
+
+mailerRegistry.register('resend', async () => {
+  const { createResendMailer } = await import('@kit/resend');
+
+  return createResendMailer();
+});
+
+export { mailerRegistry };