Adding support to use OAuth2 as the authentication method

Mail.ts

@@ -5,10 +5,15 @@ import { info, debug, error } from "./Log";
 
 export interface ISmtpConfig {
     smtp: {
+        type?: string,
         host?: string;
         port?: number;
         user?: string;
         password?: string;
+        clientId?: string,
+        clientSecret?: string,
+        accessToken?: string,
+        refreshToken?: string,
         secure?: boolean;
         from?: string;
         disabled: boolean;
@@ -30,19 +35,28 @@ export interface IMessage {
 
 export class Mail {
     private _template = "<p><!-- body --></p><p><!-- timeStamp --></p>";
+    private _authTypes = ['plain', 'oauth2'];
 
     constructor(private _config: ISmtpConfig) {
-        if (!this._config.smtp)
+        const _smtp = this._config.smtp;
+        if (!_smtp)
             this._config.smtp = { disabled: true };
 
-        if (this._config.smtp.disabled === true)
+        if (_smtp.disabled === true)
             return; // don't analyze config if disabled
 
-        if (!this._config.smtp)
-            throw new Error(`[smtp] not set`);
-        if (!this._config.smtp.host)
+        if (!_smtp.type || _smtp.type === 'plain|oauth2') {
+            _smtp.type = "plain";
+        }
+
+        if (!this._authTypes.includes(_smtp.type.trim().toLowerCase())) 
+            throw new Error(`[smtp.type] Authentication type not found ${_smtp.type.trim().toLowerCase()}`);
+
+        _smtp.type = _smtp.type.trim().toLowerCase();
+
+        if (!_smtp.host)
             throw new Error(`[smtp.host] not set`);
-        if (!this._config.smtp)
+        if (!_smtp.port)
             throw new Error(`[smtp.port] not set`);
 
         try {
@@ -73,12 +87,22 @@ export class Mail {
             name: typeof this._config.smtp.clientHostName == "string" && this._config.smtp.clientHostName ? this._config.smtp.clientHostName : null
         };
 
-        if (this._config.smtp.user)
+        if (this._config.smtp.type === 'plain' && this._config.smtp.user)
             temp.auth = {
                 user: this._config.smtp.user,
                 pass: this._config.smtp.password
             };
 
+        if (this._config.smtp.type === 'oauth2')
+            temp.auth = {
+                type: 'OAuth2',
+                user: this._config.smtp.user,
+                clientId: this._config.smtp.clientId,
+                clientSecret: this._config.smtp.clientSecret,
+                accessToken: this._config.smtp.accessToken,
+                refreshToken: this._config.smtp.refreshToken
+            }
+
         const
             transport = Mailer.createTransport(temp),
             headers = {};

README.md

@@ -20,11 +20,16 @@ After installation run `pm2 conf` to configure module. Alternatively edit `modul
 ```json
 "pm2-health": {
     "smtp": {
+        "type": "plain|oauth2", // optional, if not set plain is the default
         "host": "your-smtp-host",
         "port": 587,
         "from": "your-from-mail", // if not set, user will be used
         "user": "your-smtp-user",   // auth
         "password": "your-smtp-password",   // auth
+        "clientId": "client-id", //OAuth2 clientId
+        "clientSecret": "client-secret", //OAuth2 clientSecret
+        "accessToken": "access-token", //OAuth2 accessToken
+        "refreshToken": "refresh-token", //OAuth2 refreshToken
         "secure": false,
         "disabled": false,
         "clientHostName": "your-machine.com", // optional, will force the client host-name FQDN used in SMTP HELLO. If not set, NodeMailer will ask host name to the OS, and use 127.0.0.1 if it's not a FQDN.
@@ -38,6 +43,8 @@ After installation run `pm2 conf` to configure module. Alternatively edit `modul
 
 * `smtp` - SMTP server configuration. If your SMTP doesn't require auth, leave `smtp.user` empty
 
+* `type` - Use Plain or OAuth2 as per your need
+
 * `mailTo` - comma separated list of notification receipients
 
 * `replyTo` - reply to address (optional)