API/test/common/common.mail.test.ts

// common.mail relays one email through the Salesforce org (see
// src/common/common.mail.ts). These tests mock the shared Salesforce client so
// no network is touched, and check: the payload shape, base64 attachment
// encoding, the attachment size cap, the retry-once-on-transient-failure
// behaviour, and that a delivery failure is swallowed (returns false, never
// throws).

jest.mock('../../src/common/salesforce.client');
jest.mock('../../src/middleware/logger', () => ({
	__esModule: true,
	default: {info: jest.fn(), warn: jest.fn(), error: jest.fn()}
}));

import {MailService} from '../../src/common/common.mail';
import {salesforceApexRestPost, salesforceEnabled} from '../../src/common/salesforce.client';

const mockPost = salesforceApexRestPost as jest.Mock;
const mockEnabled = salesforceEnabled as jest.Mock;

const httpError = (status: number, body?: any): any => {
	const err: any = new Error('request failed with ' + status);
	err.response = {status, data: body};
	return err;
};

beforeEach(() => {
	jest.clearAllMocks();
	mockEnabled.mockReturnValue(true);
	mockPost.mockResolvedValue({status: 'SENT'});
});

describe('MailService.sendMail', () => {
	it('returns false without a callout when Salesforce is disabled', async () => {
		mockEnabled.mockReturnValue(false);

		const result = await MailService.sendMail('guest@example.com', 'Hi', 'Hallo');

		expect(result).toBe(false);
		expect(mockPost).not.toHaveBeenCalled();
	});

	it('posts the email to the Apex REST endpoint and returns true on success', async () => {
		const result = await MailService.sendMail('guest@example.com', 'Bestätigung', 'Hallo', {html: '<p>Hallo</p>'});

		expect(result).toBe(true);
		expect(mockPost).toHaveBeenCalledWith('/services/apexrest/email/send', {
			to: 'guest@example.com',
			subject: 'Bestätigung',
			textBody: 'Hallo',
			htmlBody: '<p>Hallo</p>',
			attachments: []
		});
	});

	it('sends htmlBody as null when no HTML is given', async () => {
		await MailService.sendMail('guest@example.com', 'Hi', 'Hallo');

		expect(mockPost).toHaveBeenCalledWith('/services/apexrest/email/send', expect.objectContaining({htmlBody: null}));
	});

	it('base64-encodes attachments', async () => {
		await MailService.sendMail('guest@example.com', 'Hi', 'Hallo', {
			attachments: [{filename: 'konzert.ics', content: 'BEGIN:VCALENDAR', contentType: 'text/calendar'}]
		});

		expect(mockPost).toHaveBeenCalledWith(
			'/services/apexrest/email/send',
			expect.objectContaining({
				attachments: [{
					filename: 'konzert.ics',
					contentType: 'text/calendar',
					contentBase64: Buffer.from('BEGIN:VCALENDAR', 'utf-8').toString('base64')
				}]
			})
		);
	});

	it('rejects an attachment over the size cap without sending', async () => {
		const huge = Buffer.alloc(3 * 1024 * 1024 + 1);

		const result = await MailService.sendMail('guest@example.com', 'Hi', 'Hallo', {
			attachments: [{filename: 'big.pdf', content: huge}]
		});

		expect(result).toBe(false);
		expect(mockPost).not.toHaveBeenCalled();
	});

	it('retries once on a 5xx and returns false when the retry also fails', async () => {
		mockPost.mockRejectedValue(httpError(503));

		const result = await MailService.sendMail('guest@example.com', 'Hi', 'Hallo');

		expect(result).toBe(false);
		expect(mockPost).toHaveBeenCalledTimes(2);
	});

	it('retries once on a network error (no response) then succeeds', async () => {
		mockPost.mockRejectedValueOnce(new Error('socket hang up')).mockResolvedValueOnce({status: 'SENT'});

		const result = await MailService.sendMail('guest@example.com', 'Hi', 'Hallo');

		expect(result).toBe(true);
		expect(mockPost).toHaveBeenCalledTimes(2);
	});

	it('does not retry on a 4xx (e.g. the 429 limit response) and returns false', async () => {
		mockPost.mockRejectedValue(httpError(429, {errorCode: 'LIMIT_REACHED'}));

		const result = await MailService.sendMail('guest@example.com', 'Hi', 'Hallo');

		expect(result).toBe(false);
		expect(mockPost).toHaveBeenCalledTimes(1);
	});
});