fix: deprecate the slack appender

docs/appenders.md

@@ -31,7 +31,6 @@ The following appenders are included with log4js. Some require extra dependencie
 * [multiFile](multiFile.md)
 * [multiprocess](multiprocess.md)
 * [recording](recording.md)
-* [slack](slack.md)
 * [stderr](stderr.md)
 * [stdout](stdout.md)
 * [rabbitmq](rabbitmq.md)
@@ -46,6 +45,7 @@ The following appenders are supported by log4js, but will issue deprecation warn
 * [logstashUDP](https://github.com/log4js-node/logstashUDP)
 * [mailgun](https://github.com/log4js-node/mailgun)
 * [redis](https://github.com/log4js-node/redis)
+* [slack](https://github.com/log4js-node/slack)
 * [smtp](https://github.com/log4js-node/smtp)
 
 For example, if you were previously using the gelf appender (`type: 'gelf'`) then you should add `@log4js-node/gelf` to your dependencies and change the type to `type: '@log4js-node/gelf'`.

examples/slack-appender.js

@@ -4,7 +4,7 @@ const log4js = require('../lib/log4js');
 log4js.configure({
   appenders: {
     slack: {
-      type: 'slack',
+      type: '@log4js-node/slack',
       token: 'TOKEN',
       channel_id: '#CHANNEL',
       username: 'USERNAME',

lib/appenders/slack.js

@@ -1,9 +1,13 @@
 'use strict';
 
+/**
+ * This appender has been deprecated.
+ * Updates and bug fixes should be made against https://github.com/log4js-node/slack
+ */
 const Slack = require('slack-node');
 
 function slackAppender(_config, layout, slack) {
-  return (loggingEvent) => {
+  const appender = (loggingEvent) => {
     const data = {
       channel_id: _config.channel_id,
       text: layout(loggingEvent, _config.timezoneOffset),
@@ -23,6 +27,10 @@ function slackAppender(_config, layout, slack) {
       }
     });
   };
+
+  // trigger a deprecation warning.
+  appender.deprecated = '@logj4s-node/slack';
+  return appender;
 }
 
 function configure(_config, layouts) {