Fix downloading a linked css resource with no extension

pyproject.toml

@@ -66,6 +66,7 @@ test = [
     "pytest-env==1.1.5",
     "vcrpy==7.0.0; python_version >='3.10'",
     "mock==5.2.0",
+    "responses==0.25.8",
 ]
 dev = [
     {include-group = "test"},

ricecooker/utils/downloader.py

@@ -390,8 +390,12 @@ def download_assets(
                 # if we're really stuck, just default to HTML as that is most likely if this is a redirect.
                 if not ext:
                     ext = ".html"
-                subpath = os.path.dirname(filename)
-                filename = "index{}".format(ext)
+
+                subpath = filename
+                # Add the existing filename in front of index.xxx, this can contain slashes and those will result
+                # in subdirectories created in the downloaded version. This ensures multiple instances of extensionless
+                # resources referenced from a page won't clobber each other.
+                filename = filename + "/index{}".format(ext)
 
                 os.makedirs(os.path.join(destination, subpath), exist_ok=True)
 
@@ -429,7 +433,7 @@ def js_content_middleware(content, url, **kwargs):
         return content
 
     def css_node_filter(node):
-        if "rel" in node:
+        if "rel" in node.attrs:
             return "stylesheet" in node["rel"]
         return node["href"].split("?")[0].strip().endswith(".css")
 

tests/test_downloader.py

@@ -1,8 +1,49 @@
+import mimetypes
 import os
+import re
+import tempfile
 import unittest
+from pathlib import Path
+from urllib.parse import unquote
+from urllib.parse import urlparse
+
+import responses
 
 from ricecooker.utils import downloader
 
+TESTCONTENT = Path(__file__).resolve().parent / "testcontent"
+
+# Portless host used to serve the checked-in sample tree. A real host (no
+# ":port") keeps the archived paths free of colons, which are illegal in
+# Windows filenames - the reason the previous embedded-server version of this
+# test failed on Windows.
+SAMPLE_HOST = "https://example.org"
+
+
+def _serve_sample_tree(request):
+    """responses callback: serve files from tests/testcontent as a static site.
+
+    Maps the request URL path onto the on-disk sample tree so the fixtures
+    checked in for this test are served verbatim, no local web server needed.
+    """
+    rel_path = unquote(urlparse(request.url).path).lstrip("/")
+    file_path = TESTCONTENT / rel_path
+    if not file_path.is_file():
+        return (404, {}, b"")
+    ext = file_path.suffix
+    if ext == ".html":
+        content_type = "text/html; charset=utf-8"
+    elif ext == "":
+        # Extensionless resources in this fixture are stylesheets; Google Fonts
+        # serves its CSS from an extensionless URL, which is what this test
+        # exercises.
+        content_type = "text/css"
+    else:
+        content_type = (
+            mimetypes.guess_type(str(file_path))[0] or "application/octet-stream"
+        )
+    return (200, {"Content-Type": content_type}, file_path.read_bytes())
+
 
 class TestArchiver(unittest.TestCase):
     def test_get_archive_filename_absolute(self):
@@ -70,3 +111,63 @@ def test_archive_path_as_relative_url(self):
             link_filename, page_filename
         )
         assert rel_path == "../kolibri_1.2.3.png"
+
+
+# The sample tree lives under a subject folder mirroring a real PreTeXt book:
+# activecalculus.org (the page) references a stylesheet from fonts.googleapis.com
+# via an extensionless URL, whose CSS in turn references a font on
+# fonts.gstatic.com.
+SAMPLE_ROOT = "samples/PreTeXt_book_test_manually_cleaned_urls"
+# The Google Fonts stylesheet URL is extensionless; the original had a colon,
+# replaced with an underscore so the fixture file checks out on Windows.
+CSS_URL_PART = "css2_family_Material+Symbols+Outlined_opsz,wght,FILL,GRAD@24,400,0,0"
+
+
+@responses.activate
+def test_pretextbook_css_fetch():
+    """A stylesheet linked via an extensionless URL is archived and rewritten.
+
+    Regression test for two bugs when archiving a PreTeXt book: the CSS
+    ``<link>`` (matched by ``rel="stylesheet"``, not a ``.css`` extension) was
+    skipped, and the generated ``index.css`` for the extensionless resource was
+    dumped at the archive root instead of nested under the resource's own path,
+    which made its relative font references escape the archive directory.
+    """
+    responses.add_callback(
+        responses.GET,
+        re.compile(re.escape(SAMPLE_HOST) + r"/.*"),
+        callback=_serve_sample_tree,
+    )
+
+    page_url = "{}/{}/activecalculus.org/single2e/sec-5-2-FTC2.html".format(
+        SAMPLE_HOST, SAMPLE_ROOT
+    )
+
+    with tempfile.TemporaryDirectory() as download_root:
+        archive = downloader.ArchiveDownloader(download_root)
+        archive.get_page(page_url)
+
+        book_dest_dir = Path(download_root) / "example.org" / SAMPLE_ROOT
+
+        # The page's stylesheet link is rewritten to the nested index.css.
+        page_html = (
+            book_dest_dir / "activecalculus.org" / "single2e" / "sec-5-2-FTC2.html"
+        ).read_text()
+        assert "../../fonts.googleapis.com/" + CSS_URL_PART + "/index.css" in page_html
+
+        # The extensionless stylesheet is nested under its own path as index.css,
+        # not clobbered at the archive root.
+        index_css = book_dest_dir / "fonts.googleapis.com" / CSS_URL_PART / "index.css"
+        css_contents = index_css.read_text()
+        assert "fonts.gstatic.com/s/materialsymbolsoutlined" in css_contents
+
+        # The font referenced from the CSS is downloaded to its own nested path.
+        font_path = (
+            book_dest_dir
+            / "fonts.gstatic.com"
+            / "s"
+            / "materialsymbolsoutlined"
+            / "v290"
+            / "material_symbols.woff"
+        )
+        assert font_path.stat().st_size > 0

tests/testcontent/samples/PreTeXt_book_test_manually_cleaned_urls/activecalculus.org/single2e/sec-5-2-FTC2.html

@@ -0,0 +1,22 @@
+<html dir="ltr" lang="en-US">
+ <!--******************************************-->
+ <!--*  Authored with PreTeXt                 *-->
+ <!--*  pretextbook.org                       *-->
+ <!--*  Theme: default-modern                 *-->
+ <!--*  Palette: blues                        *-->
+ <!--******************************************-->
+ <head xmlns:book="https://ogp.me/ns/book#" xmlns:og="http://ogp.me/ns#">
+  <meta content="text/html; charset=utf-8" http-equiv="Content-Type"/>
+  <title>
+   AC The Second Fundamental Theorem of Calculus
+  </title>
+  <link href="" rel="preconnect"/>
+  <link crossorigin="sec-5-2-FTC2.html" href="" rel="preconnect"/>
+  <link href="../../fonts.googleapis.com/css2_family_Material+Symbols+Outlined_opsz,wght,FILL,GRAD@24,400,0,0" rel="stylesheet"/>
+ </head>
+ <body class="pretext book ignore-math">
+  <span aria-hidden="true" class="icon material-symbols-outlined">
+   
+  </span>
+ </body>
+</html>

tests/testcontent/samples/PreTeXt_book_test_manually_cleaned_urls/fonts.googleapis.com/css2_family_Material+Symbols+Outlined_opsz,wght,FILL,GRAD@24,400,0,0

@@ -0,0 +1,21 @@
+@font-face {
+  font-family: 'Material Symbols Outlined';
+  font-style: normal;
+  font-weight: 400;
+  src: url("../fonts.gstatic.com/s/materialsymbolsoutlined/v290/material_symbols.woff") format('woff');
+}
+
+.material-symbols-outlined {
+  font-family: 'Material Symbols Outlined';
+  font-weight: normal;
+  font-style: normal;
+  font-size: 24px;
+  line-height: 1;
+  letter-spacing: normal;
+  text-transform: none;
+  display: inline-block;
+  white-space: nowrap;
+  word-wrap: normal;
+  direction: ltr;
+  -moz-font-feature-settings: 'liga';
+}

tests/testcontent/samples/PreTeXt_book_test_manually_cleaned_urls/fonts.gstatic.com/s/materialsymbolsoutlined/v290/material_symbols.woff

@@ -0,0 +1 @@
+Not really a font, just a placeholder file.