ibm-plex: add update script

pkgs/by-name/ib/ibm-plex/package.nix

@@ -63,6 +63,8 @@ symlinkJoin {
   pname = "ibm-plex";
   version = "0-unstable-2026-02-12";
   paths = lib.attrValues fontDerivations;
-  passthru = fontDerivations;
+  passthru = fontDerivations // {
+    updateScript = ./update.py;
+  };
   inherit meta;
 }

pkgs/by-name/ib/ibm-plex/update.py

@@ -0,0 +1,85 @@
+#! /usr/bin/env nix-shell
+#! nix-shell -i python3 -p nix nix-prefetch python3
+import json
+import subprocess
+import urllib.request
+
+fonts_file = "fonts.nix"
+fonts_data = json.loads(
+    subprocess.check_output(["nix", "eval", "--json", "-f", fonts_file])
+)
+
+releases_url = "https://api.github.com/repos/IBM/plex/releases"
+releases = json.loads(urllib.request.urlopen(releases_url).read())
+
+for font in fonts_data.keys():
+    font_tag = f"@ibm/plex-{font}@"
+    font_file = f"plex-{font}.zip"
+    current_version = fonts_data.get(font, {}).get("version")
+
+    latest_release = next(
+        (r for r in releases if r["tag_name"].lower().startswith(font_tag)), None
+    )
+
+    if latest_release is None:
+        print(f"No release found for {font}")
+        continue
+
+    latest_version = latest_release["tag_name"].split("@")[-1]
+
+    if current_version == latest_version:
+        print(f"Font {font} is up-to-date")
+        continue
+
+    print(f"Updating {font} from {current_version} to {latest_version}")
+
+    asset = next(
+        (
+            a
+            for a in latest_release["assets"]
+            if font_file.lower() in a["name"].lower()
+        ),
+        None,
+    )
+
+    if asset is None:
+        print(f"Warning: No asset found for {font}")
+        continue
+
+    asset_url = asset["browser_download_url"]
+
+    raw_hash = (
+        subprocess.check_output(["nix-prefetch-url", "--unpack", asset_url])
+        .decode()
+        .strip()
+    )
+
+    sri_hash = (
+        subprocess.check_output(
+            ["nix", "--extra-experimental-features", "nix-command", "hash", "convert", "--hash-algo", "sha256", raw_hash]
+        )
+        .decode()
+        .strip()
+    )
+
+    for x, y in zip(
+        ["version", "hash", "url"],
+        [latest_version, sri_hash, asset_url]
+    ):
+        if fonts_data[font].get(x) != y:
+            fonts_data[font][x] = y
+
+
+with open(fonts_file, "w") as f:
+    f.write("{\n")
+    for font in sorted(fonts_data.keys()):
+        attrs = fonts_data[font]
+        f.write(f"  {font} = {{\n")
+        for k in sorted(attrs.keys()):
+            v = attrs[k]
+            if isinstance(v, bool):
+                f.write(f"    {k} = {'true' if v else 'false'};\n")
+            else:
+                f.write(f'    {k} = "{v}";\n')
+        f.write("  };\n")
+    f.write("}\n")