fix: getTransport to handle overrides more cleanly

packages/smtppostmaster/__tests__/send.test.ts

@@ -2,11 +2,21 @@ import { send, resetTransport } from '../src/index';
 import { createSmtpCatcher } from './smtp-catcher';
 
 describe('send', () => {
+  const ORIGINAL_ENV = { ...process.env };
+
   afterEach(() => {
     resetTransport();
+    // Remove any env var added during the test
+    for (const key of Object.keys(process.env)) {
+      if (!(key in ORIGINAL_ENV)) {
+        delete process.env[key];
+      }
+    }
+    // Restore original values
+    Object.assign(process.env, ORIGINAL_ENV);
   });
 
-  it('sends email via SMTP catcher', async () => {
+  it('sends email via SMTP catcher with overrides', async () => {
     const catcher = await createSmtpCatcher();
 
     try {
@@ -33,4 +43,76 @@ describe('send', () => {
       await catcher.stop();
     }
   }, 10000);
+
+  it('sends email using SMTP config from environment variables', async () => {
+    const catcher = await createSmtpCatcher();
+
+    // Set SMTP config via environment variables
+    process.env.SMTP_HOST = catcher.host;
+    process.env.SMTP_PORT = String(catcher.port);
+    process.env.SMTP_SECURE = 'false';
+    process.env.SMTP_FROM = '[email protected]';
+    process.env.SMTP_TLS_REJECT_UNAUTHORIZED = 'false';
+    process.env.SMTP_REQUIRE_TLS = 'false';
+
+    // Clear cached transport to pick up new env vars
+    resetTransport();
+
+    try {
+      // Send without overrides - should use env vars
+      await send({
+        to: '[email protected]',
+        subject: 'Email from env config',
+        text: 'This email was sent using env var configuration.'
+      });
+
+      const message = await catcher.waitForMessage(5000);
+
+      expect(message.raw).toContain('Subject: Email from env config');
+      expect(message.raw).toContain('This email was sent using env var configuration.');
+      expect(message.raw).toContain('From: [email protected]');
+    } finally {
+      await catcher.stop();
+    }
+  }, 10000);
+
+  it('overrides take precedence over environment variables', async () => {
+    const catcher = await createSmtpCatcher();
+
+    // Set env vars with WRONG port - would fail if used
+    process.env.SMTP_HOST = '127.0.0.1';
+    process.env.SMTP_PORT = '59999';
+    process.env.SMTP_SECURE = 'false';
+    process.env.SMTP_FROM = '[email protected]';
+
+    // Clear cached transport
+    resetTransport();
+
+    try {
+      // Send with overrides - should use overrides (correct port), not env vars
+      await send(
+        {
+          to: '[email protected]',
+          subject: 'Override test',
+          text: 'This email should use override config, not env.'
+        },
+        {
+          host: catcher.host,
+          port: catcher.port, // Correct port from catcher
+          secure: false,
+          from: '[email protected]',
+          tlsRejectUnauthorized: false
+        }
+      );
+
+      const message = await catcher.waitForMessage(5000);
+
+      expect(message.raw).toContain('Subject: Override test');
+      expect(message.raw).toContain('This email should use override config');
+      expect(message.raw).toContain('From: [email protected]');
+      expect(message.raw).not.toContain('From: [email protected]');
+    } finally {
+      await catcher.stop();
+    }
+  }, 10000);
 });

packages/smtppostmaster/src/index.ts

@@ -92,7 +92,7 @@ let transport: nodemailer.Transporter<SMTPTransport.SentMessageInfo> | undefined
 let cachedSmtpOpts: SmtpOptions | undefined;
 
 const getTransport = (overrides?: SmtpOptions) => {
-  const opts = getEnvOptions({ smtp: overrides });
+  const opts = getEnvOptions(overrides ? { smtp: overrides } : {});
   const smtpOpts = opts.smtp ?? {};
 
   if (!transport || overrides) {