Independent generation of latest.json file

The new script loads releases from PyPI, independently of the changelog
generation script that used to handle this. If there is a prerelease
newer than the current stable version, that will be the `unstable`
version, instead of an alias to the current stable version.

Leans on `packaging.version` to do the heavy lifting (parsing version
specifiers into sortable `Version` objects). Fortunately we already get
`packaging` and `requests` for free when installing `_sopel` to document
it and its plugins.

Co-authored-by: James <snoopjedi@gmail.com>

document_versions.py

@@ -74,15 +74,6 @@ def main(argv=None):
 
     print("Done! {} versions documented.".format(len(versions.keys())))
 
-    latest = list(versions.keys())[0]
-    with open('latest.json', 'w') as f:
-        f.write("{{\n"  # double braces so Python doesn't get confused
-                "    \"version\": \"{version}\",\n"
-                "    \"unstable\": \"{version}\",\n"
-                "    \"release_notes\": \"https://sopel.chat/changelog/{version}/\"\n"
-                "}}".format(version=latest))
-
-    print("Generated latest.json file pointing to version {}.".format(latest))
 
 if __name__ == '__main__':
     main()

generate_latest_json.py

@@ -0,0 +1,50 @@
+#!/usr/bin/env python3
+"""
+Sopel update-check JSON generation utility
+
+This script creates a `latest.json` file representing the most recent stable and
+unstable `sopel` releases published to PyPI, using PyPI's own JSON API.
+
+Copyright 2024 dgw, technobabbl.es
+Licensed under the Eiffel Forum License 2.
+
+https://sopel.chat
+"""
+import json
+import sys
+
+from packaging.version import parse as parse_version
+import requests
+
+
+def main(argv=None):
+    response = requests.get('https://pypi.org/pypi/sopel/json')
+    response.raise_for_status()
+    data = response.json()
+    releases = sorted(parse_version(v) for v in data['releases'].keys())
+
+    latest = releases[-1]
+    stable = latest
+    if latest.is_prerelease:
+        stable_releases_rev = (ver for ver in reversed(releases[:-1]) if not ver.is_prerelease)
+        try:
+            stable = next(stable_releases_rev)
+        except StopIteration:
+            print("ERROR: Latest version is a prerelease, but no earlier stable version found!")
+            sys.exit(1)
+
+    with open('latest.json', 'w') as f:
+        sopel_version_info = {
+            "version": str(stable),
+            "unstable": str(latest),
+            "release_notes": f"https://sopel.chat/changelog/{stable}/",
+            "unstable_notes": f"https://github.com/sopel-irc/sopel/releases/v{latest}",
+        }
+        json.dump(sopel_version_info, f, indent=4)
+
+    print("Generated latest.json file pointing to {} (stable) + {} (unstable)."
+          .format(stable, latest))
+
+
+if __name__ == '__main__':
+    main()

netlify-build.sh

@@ -3,12 +3,15 @@ set -e
 
 echo "Starting custom build script..."
 
-echo "Generating changelogs & latest.json file"
+echo "Generating changelogs"
 python3 document_versions.py --news=_sopel/NEWS
 
 echo "Installing Sopel globally for plugin autodoc script"
 pip3 install ./_sopel
 
+echo "Generating latest.json file"
+python3 generate_latest_json.py
+
 echo "Generating plugin command/config pages"
 python3 document_sopel_plugins.py --sopel=_sopel