ci: add script to check README against plugins list

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-rs/-/merge_requests/2443>

.gitlab-ci.yml

@@ -340,6 +340,14 @@ check commits:
     - ci/check-for-symlinks.sh
     - ci/check-meson-version.sh
 
+check readme:
+  extends: '.debian:12-stable'
+  stage: "lint"
+  tags: [ 'placeholder-job' ]
+  needs: []
+  script:
+    - ci/check-readme-against-plugins-list.py
+
 clippy:
   extends: '.debian:12-stable'
   needs:

ci/check-readme-against-plugins-list.py

@@ -0,0 +1,63 @@
+#!/usr/bin/env python3
+#
+# check-readme-against-plugins-list.py:
+#
+# Check that the README.md covers all plugins in the plugin list.
+
+import json
+import sys
+
+# Read README.md
+with open('README.md') as f:
+    readme = f.read()
+
+# Read plugins doc cache
+with open('docs/plugins/gst_plugins_cache.json', 'r') as f:
+    docs = json.load(f)
+
+plugins = list(docs.keys())
+
+missing_plugins = []
+covered_plugins = []
+
+# Some plugins are listed with their subdir which doesn't match the plugin name
+plugins_remap = {
+    'rsflv': 'flavors',
+    'textahead': 'ahead',
+    'textwrap': 'wrap',
+}
+
+for plugin_name in plugins:
+    if plugin_name in plugins_remap:
+        plugin_name = plugins_remap[plugin_name]
+
+    plugin_bullet_line = f'- `{plugin_name}`:'
+    if plugin_name.startswith('rs'):
+        name2 = plugin_name[2:]
+        plugin_bullet_line2 = f'- `{name2}`:'
+    else:
+        plugin_bullet_line2 = plugin_bullet_line
+    if not plugin_bullet_line in readme and not plugin_bullet_line2 in readme:
+        print(f'{plugin_name}: Missing!')
+        missing_plugins += [plugin_name]
+    else:
+        print(f'{plugin_name}: Ok')
+
+if missing_plugins:
+    sys.exit(
+        '\nMissing plugins in README.md:\n - {}'.format('\n - '.join(missing_plugins)))
+
+sys.exit(0)
+
+# FIXME: for later if we want full coverage of all element names too
+'''
+factories = []
+
+for plugin_name in plugins:
+    plugin = docs[plugin_name]
+    #print(json.dumps(plugin, indent=4))
+    factories += list(plugin['elements'].keys())
+
+print()
+print('Elements:', factories)
+'''