Implement cache busting: append a suffix to CSS and JS URLs

mkdocs/commands/build.py

@@ -36,9 +36,9 @@ def get_context(nav, files, config, page=None, base_url=''):
     if page is not None:
         base_url = utils.get_relative_url('.', page.url)
 
-    extra_javascript = utils.create_media_urls(config['extra_javascript'], page, base_url)
+    extra_javascript = utils.create_media_urls(config['site_dir'], config['extra_javascript'], page, base_url)
 
-    extra_css = utils.create_media_urls(config['extra_css'], page, base_url)
+    extra_css = utils.create_media_urls(config['site_dir'], config['extra_css'], page, base_url)
 
     if isinstance(files, Files):
         files = files.documentation_pages()

mkdocs/utils/__init__.py

@@ -14,6 +14,7 @@
 import fnmatch
 import posixpath
 import functools
+import hashlib
 import importlib_metadata
 from collections import defaultdict
 from datetime import datetime, timezone
@@ -296,10 +297,22 @@ def _get_rel_path(path, base, base_is_url):
         return posixpath.join(base, path)
 
 
-def create_media_urls(path_list, page=None, base=''):
+@functools.lru_cache()
+def _file_digest(filename):
+    with open(filename, 'rb') as f:
+        content = f.read()
+    return hashlib.sha256(content).hexdigest()[:8]
+
+
+def create_media_urls(site_dir, path_list, page=None, base=''):
     """
     Return a list of URLs relative to the given page or using the base.
     """
+    for i, path in enumerate(path_list):
+        try:
+            path_list[i] += '?' + _file_digest(os.path.join(site_dir, path))
+        except FileNotFoundError:
+            pass
     return [normalize_url(path, page, base) for path in path_list]