discord: Add update script for darwin

Artturin · Artturin · commit 2958e1b60ae7 · 2023-10-02T08:54:04.000+03:00
Runnable on linux with

```
nix-shell maintainers/scripts/update.nix --argstr commit true --argstr package pkgsCross.aarch64-darwin.discord
```

The generated commit will have the pkgsCross prefix so that has to be
removed manually

`pkgsCross.aarch64-darwin.discord-canary: 0.0.312 -&gt; 0.0.314`
diff --git a/pkgs/applications/networking/instant-messengers/discord/darwin.nix b/pkgs/applications/networking/instant-messengers/discord/darwin.nix
@@ -1,4 +1,4 @@
-{ pname, version, src, meta, stdenv, binaryName, desktopName, lib, undmg, makeWrapper
+{ pname, version, src, meta, stdenv, binaryName, desktopName, lib, undmg, makeWrapper, writeScript
 , branch
 , withOpenASAR ? false, openasar
 , withVencord ? false, vencord }:
@@ -31,4 +31,19 @@ stdenv.mkDerivation {
     echo '{"name":"discord","main":"index.js"}' > $out/Applications/${desktopName}.app/Contents/Resources/app.asar/package.json
     echo 'require("${vencord}/patcher.js")' > $out/Applications/${desktopName}.app/Contents/Resources/app.asar/index.js
   '';
+
+  passthru = {
+    updateScript = writeScript "discord-update-script" ''
+      #!/usr/bin/env nix-shell
+      #!nix-shell -i bash -p curl gnugrep common-updater-scripts
+      set -x
+      set -eou pipefail;
+      url=$(curl -sI "https://discordapp.com/api/download/${
+        builtins.replaceStrings [ "discord-" "discord" ] [ "" "stable" ] pname
+      }?platform=osx&format=dmg" | grep -oP 'location: \K\S+')
+      version=''${url##https://dl*.discordapp.net/apps/osx/}
+      version=''${version%%/*.dmg}
+      update-source-version ${lib.optionalString (!stdenv.buildPlatform.isDarwin) "pkgsCross.aarch64-darwin."}${pname} "$version" --file=./pkgs/applications/networking/instant-messengers/discord/default.nix --version-key=${branch}
+    '';
+  };
 }
