Added shared mailer package to remove circular dependencies between packages. (#63)

packages/mailers/resend/src/index.ts

@@ -0,0 +1,53 @@
+import 'server-only';
+
+import { z } from 'zod';
+
+import { Mailer, MailerSchema } from '@kit/mailers-shared';
+
+type Config = z.infer<typeof MailerSchema>;
+
+const RESEND_API_KEY = z
+  .string({
+    description: 'The API key for the Resend API',
+    required_error: 'Please provide the API key for the Resend API',
+  })
+  .parse(process.env.RESEND_API_KEY);
+
+export function createResendMailer() {
+  return new ResendMailer();
+}
+
+/**
+ * A class representing a mailer using the Resend HTTP API.
+ * @implements {Mailer}
+ */
+class ResendMailer implements Mailer {
+  async sendEmail(config: Config) {
+    const contentObject =
+      'text' in config
+        ? {
+            text: config.text,
+          }
+        : {
+            html: config.html,
+          };
+
+    const res = await fetch('https://api.resend.com/emails', {
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/json',
+        Authorization: `Bearer ${RESEND_API_KEY}`,
+      },
+      body: JSON.stringify({
+        from: config.from,
+        to: [config.to],
+        subject: config.subject,
+        ...contentObject,
+      }),
+    });
+
+    if (!res.ok) {
+      throw new Error(`Failed to send email: ${res.statusText}`);
+    }
+  }
+}