I like things clean. So I don’t want Slack’s lacking settings to remove the unread bullet in the badge. (Unlike the mentioned/DM messages which show a number in the badge, unread messages in channels show •)

Because Slack’s Mac App is built using Electron framework, I was thinking of hacking the source code to remove the “feature”.

I went to /Applications/Slack.app/Contents/Resources, and uncompressed app.asar using asar e app.asar <tmp dir>. I tried to hack around and re-packed the code, but it seemed not to work. I suspect Slack downloads latest javascript files from their own server. I didn’t want to take time to do the MitM, which could be tedious.

Then I saw electron.asar in the same directory of app.asar. It turned out to be a much easier way to achieve my goal. The diff is quite straightforward:

diff --git a/browser/api/app.js b/browser/api/app.js
index 381a2a8..0d0cdad 100644
--- a/browser/api/app.js
+++ b/browser/api/app.js
@@ -44,7 +44,13 @@ if (process.platform === 'darwin') {
     },
     cancelBounce: bindings.dockCancelBounce,
     downloadFinished: bindings.dockDownloadFinished,
-    setBadge: bindings.dockSetBadgeText,
+    //setBadge: bindings.dockSetBadgeText,
+    setBadge (label) {
+        if (label === '•') {
+            label = ''
+        }
+        return bindings.dockSetBadgeText(label)
+    },
     getBadge: bindings.dockGetBadgeText,
     hide: bindings.dockHide,
     show: bindings.dockShow,

Tip: to get console output, add console.info as usual, and start the application in the terminal, like /Applications/Slack.app/Contents/MacOS/Slack and the output will be in the stdout.