Add a probation period for mentions;

config.example.js

@@ -8,8 +8,13 @@ module.exports = {
         'somebody': ['push', 'merge_request', 'issue', 'build']
     },
 
+    // Project URL used for mentions of MR (e.g. !123) or issues (#122).
     projectUrl: "https://framagit.org/bnjbvr/kresus/",
 
+    // Amout of time (in ms) during which no other mentions to a same MR/issue
+    // will be done.
+    cacheDuration: 10000,
+
     branches: ['master'],
 
     // IRC nick/names for the bot

index.js

@@ -218,7 +218,19 @@ app.post('/', function(req, res) {
     res.sendStatus(200);
 });
 
+var cache = {};
+function makeCacheKey(isIssue, id, chan) {
+    return chan + '-' + (isIssue ? 'issue' : 'mr') + id;
+}
+
 function fetch_and_say(isIssue, id, from, chan) {
+    var cacheKey = makeCacheKey(isIssue, id, chan);
+
+    // Don't mention if it's been already mentioned in the last
+    // config.cacheDuration ms.
+    if (typeof cache[cacheKey] !== 'undefined')
+        return;
+
     var path, text_prefix;
     if (isIssue) {
         path = 'issues/';
@@ -240,6 +252,9 @@ function fetch_and_say(isIssue, id, from, chan) {
             } else {
                 client.say(to, text_prefix + id + ": " + url);
             }
+            cache[cacheKey] = setTimeout(function() {
+                delete cache[cacheKey];
+            }, config.cacheDuration);
         }
     });
 }