From c18f29bd396f0bc97296cb03d031e25203871540 Mon Sep 17 00:00:00 2001
From: Jake Howard <git@theorangeone.net>
Date: Fri, 15 Sep 2023 22:29:43 +0100
Subject: [PATCH] Add SRI extension

---
 hooks/pygments-styles.py |  9 +++++----
 hooks/static.py          | 17 ++++++++++++++++-
 hooks/tags.py            |  2 +-
 theme/main.html          |  3 +++
 4 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/hooks/pygments-styles.py b/hooks/pygments-styles.py
index 9252bdc..c0f093a 100644
--- a/hooks/pygments-styles.py
+++ b/hooks/pygments-styles.py
@@ -6,8 +6,9 @@ from minify_html import minify
 from mkdocs.utils import write_file, clean_directory
 
 PYGMENTS_STYLE_DIR = tempfile.mkdtemp()
+PYGMENTS_STYLES_DEST = "assets/pygments.css"
 
-def on_post_build(config):
+def on_post_build(*args, **kwargs):
     clean_directory(PYGMENTS_STYLE_DIR)
 
 on_build_error = on_pre_build = on_post_build
@@ -21,15 +22,15 @@ def minify_css(styles: str) -> str:
 
 
 def on_files(files, config):
-    style_file = os.path.join(PYGMENTS_STYLE_DIR, "pygments.css")
+    style_file = os.path.join(PYGMENTS_STYLE_DIR, PYGMENTS_STYLES_DEST)
 
     style = minify_css(HtmlFormatter(style="monokai").get_style_defs())
 
     write_file(style.encode(), style_file)
 
     files.append(File(
-        path=os.path.basename(style_file),
+        path=PYGMENTS_STYLES_DEST,
         src_dir=PYGMENTS_STYLE_DIR,
-        dest_dir=os.path.join(config["site_dir"], "assets"),
+        dest_dir=config["site_dir"],
         use_directory_urls=False
     ))
diff --git a/hooks/static.py b/hooks/static.py
index d035fe2..f91a914 100644
--- a/hooks/static.py
+++ b/hooks/static.py
@@ -43,6 +43,7 @@ def on_files(files: Files, config):
 
 def on_env(env: jinja2.Environment, config, files):
     env.add_extension(make_static_extension(files))
+    env.add_extension(make_sri_extension(files))
 
     return env
 
@@ -52,6 +53,20 @@ def make_static_extension(files: Files):
 
         def render(self, filename):
             file = files.get_file_from_path(filename)
-            return file.url
+            return f"/{file.url}"
 
     return StaticExtension
+
+
+def make_sri_extension(files: Files):
+    class SRIExtension(StandaloneTag):
+        tags = {"sri_integrity"}
+
+        def render(self, filename):
+            file = files.get_file_from_path(filename)
+            with open(file.abs_src_path, "rb") as f:
+                digest = hashlib.file_digest(f, "sha256").hexdigest()
+
+            return f"sha256-{digest}"
+
+    return SRIExtension
diff --git a/hooks/tags.py b/hooks/tags.py
index 6c9cb54..4cd3f36 100644
--- a/hooks/tags.py
+++ b/hooks/tags.py
@@ -5,7 +5,7 @@ import os
 
 TAGS_TEMP_DIR = tempfile.mkdtemp()
 
-def on_post_build(config):
+def on_post_build(*args, **kwargs):
     clean_directory(TAGS_TEMP_DIR)
 
 on_build_error = on_pre_build = on_post_build
diff --git a/theme/main.html b/theme/main.html
index c9a55c0..30f7f69 100644
--- a/theme/main.html
+++ b/theme/main.html
@@ -19,3 +19,6 @@ URL: {{ get_page_url("tags/tag1.md") }}
 Image resized: {{ "./assets/test.jpg"|resize_image(1500) }}
 
 Globals: {{ globals.foo }}
+
+Static path: {% static "assets/pygments.css" %}
+SRI: {% sri_integrity "assets/pygments.css" %}