Add scripting (tengo) support for every incoming message (#731)

TengoModifyMessage allows you to specify the location of a tengo (https://github.com/d5/tengo/) script.
This script will receive every incoming message and can be used to modify the Username and the Text of that message.
The script will have the following global variables:
to modify: msgUsername and msgText
to read: msgChannel and msgAccount

The script is reloaded on every message, so you can modify the script on the fly.

Example script can be found in https://github.com/42wim/matterbridge/tree/master/gateway/bench.tengo
and https://github.com/42wim/matterbridge/tree/master/contrib/example.tengo

The example below will check if the text contains blah and if so, it'll replace the text and the username of that message.
text := import("text")
if text.re_match("blah",msgText) {
    msgText="replaced by this"
    msgUsername="fakeuser"
}

More information about tengo on: https://github.com/d5/tengo/blob/master/docs/tutorial.md and
https://github.com/d5/tengo/blob/master/docs/stdlib.md

1 files changed, 1 insertions, 0 deletions

diff --git a/bridge/config/config.go b/bridge/config/config.go
index 7ab6aef4..47914951 100644
--- a/bridge/config/config.go
+++ b/bridge/config/config.go
@@ -129,6 +129,7 @@ type Protocol struct {
 	SkipTLSVerify          bool       // IRC, mattermost
 	StripNick              bool       // all protocols
 	SyncTopic              bool       // slack
+	TengoModifyMessage     string     // general
 	Team                   string     // mattermost
 	Token                  string     // gitter, slack, discord, api
 	Topic                  string     // zulip