support multiple recipients (#12)

src/handlers.js

@@ -2,11 +2,16 @@ import { mail } from './mail';
 import { params } from './params';
 
 const postApiNotify = async ({ env, request }) => {
-  const { errors = [], ...rest } = await params(request);
-  await mail({
-    env,
-    ...rest,
+  const { to, errors = [], ...rest } = await params(request);
+  const recipients = to?.split(',') ?? [];
+  recipients.map(async (recipient) => {
+    await mail({
+      env,
+      to: recipient,
+      ...rest,
+    });
   });
+
   const response = {
     ...rest,
     ...(errors.length && { errors }),

src/handlers.spec.js

@@ -1,6 +1,7 @@
 import { describe, it, expect, beforeAll, vi } from 'vitest';
 import { handler } from './handlers';
 import { input } from './test';
+import { payload } from './mail';
 
 describe('handlers', () => {
   beforeAll(() => {
@@ -28,18 +29,55 @@ describe('handlers', () => {
     expect(response.status).toEqual(404);
   });
 
-  it('postNotify', async () => {
-    const request = new Request('http://example.com/api/notify', {
-      method: 'POST',
-      headers: {
-        'Content-Type': 'application/json',
-      },
-      body: JSON.stringify(input),
+  describe('postNotify', () => {
+    it('calls the sendgrid api', async () => {
+      const request = new Request('http://example.com/api/notify', {
+        method: 'POST',
+        headers: {
+          'Content-Type': 'application/json',
+        },
+        body: JSON.stringify(input),
+      });
+      await handler({ request });
+      expect(global.fetch).toHaveBeenCalledWith(
+        'https://api.sendgrid.com/v3/mail/send',
+        expect.anything(),
+      );
+    });
+    it('supports multiple recipients', async () => {
+      global.fetch = vi.fn();
+      const request = new Request('http://example.com/api/notify', {
+        method: 'POST',
+        headers: {
+          'Content-Type': 'application/json',
+        },
+        body: JSON.stringify({
+          ...input,
+          to: '[email protected],[email protected]',
+        }),
+      });
+      await handler({ request });
+      expect(global.fetch).toHaveBeenCalledTimes(2);
+
+      const requestBody = (email) => ({
+        body: JSON.stringify(
+          payload({
+            ...input,
+            to: email,
+          }),
+        ),
+        headers: expect.any(Object),
+        method: 'POST',
+      });
+
+      expect(global.fetch).toHaveBeenCalledWith(
+        'https://api.sendgrid.com/v3/mail/send',
+        requestBody('[email protected]'),
+      );
+      expect(global.fetch).toHaveBeenCalledWith(
+        'https://api.sendgrid.com/v3/mail/send',
+        requestBody('[email protected]'),
+      );
     });
-    await handler({ request });
-    expect(global.fetch).toHaveBeenCalledWith(
-      'https://api.sendgrid.com/v3/mail/send',
-      expect.anything(),
-    );
   });
 });

src/mail.js

@@ -1,4 +1,4 @@
-const payload = ({ subject, to, body, attachments }) => ({
+export const payload = ({ subject, to, body, attachments }) => ({
   // https://docs.sendgrid.com/api-reference/mail-send/mail-send#body
   attachments,
   content: [