feat/overview (#5435)

- fixes issues with xml structure pre commit hook
- Moves comprea-files to lib
- adds a n overview page on status.fsfe.org to see what files have different structures

Co-authored-by: Darragh Elliott <me@delliott.net>
Reviewed-on: #5435
Co-authored-by: delliott <delliott@fsfe.org>
Co-committed-by: delliott <delliott@fsfe.org>

build/fsfe_website_build/lib/checks.py

@@ -0,0 +1,86 @@
+# SPDX-FileCopyrightText: Free Software Foundation Europe e.V. <https://fsfe.org>
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
+import logging
+import sys
+from pathlib import Path
+
+from lxml import etree
+
+logger = logging.getLogger(__name__)
+
+
+def compare_files(
+    file1: Path,
+    file2: Path,
+    attr_whitelist: set[str] | None = None,
+    _path: str = "",
+) -> list[str]:
+    try:
+        t1, t2 = etree.parse(file1), etree.parse(file2)
+    except etree.XMLSyntaxError as e:
+        logger.critical("XML parse error: %s", e)
+        sys.exit(1)
+
+    return compare_elements(t1.getroot(), t2.getroot(), attr_whitelist)
+
+
+def compare_elements(
+    elem1: etree.Element,
+    elem2: etree.Element,
+    attr_whitelist: set[str] | None = None,
+    _path: str = "",
+) -> list[str]:
+    """
+    Recursively compare two XML elements.
+    Returns a list of short, informative error strings.
+    """
+    if attr_whitelist is None:
+        attr_whitelist = set()
+
+    errors: list[str] = []
+    tag_path = f"{_path}/{elem1.tag}" if _path else elem1.tag
+
+    # tag mismatch
+    if elem1.tag != elem2.tag:
+        errors.append(f"Tag mismatch at {tag_path}: {elem1.tag} ≠ {elem2.tag}")
+        return errors  # if tags differ, stop descending
+
+    # attribute deltas
+    attributes_of_elem1 = dict(elem1.attrib.items())
+    attributes_of_elem2 = dict(elem2.attrib.items())
+
+    only_in_elem1 = set(attributes_of_elem1) - set(attributes_of_elem2)
+    only_in_elem2 = set(attributes_of_elem2) - set(attributes_of_elem1)
+    common = set(attributes_of_elem1) & set(attributes_of_elem2)
+
+    if only_in_elem1 or only_in_elem2:
+        errors.append(
+            f"Attribute delta at <{elem1.tag}>"
+            f"  only 1: {list(only_in_elem1)}  only 2: {list(only_in_elem2)}"
+        )
+    for key in common:
+        if (
+            attributes_of_elem1[key] != attributes_of_elem2[key]
+            and key not in attr_whitelist
+        ):
+            error_msg = (
+                f"Attribute value diff at <{elem1.tag} {key}>:"
+                f" {attributes_of_elem1[key]!r} ≠ {attributes_of_elem2[key]!r}"
+            )
+            errors.append(error_msg)
+
+    # child count
+    kids1 = list(elem1)
+    kids2 = list(elem2)
+    if len(kids1) != len(kids2):
+        errors.append(f"Child count at <{elem1.tag}>: {len(kids1)} ≠ {len(kids2)}")
+        return errors  # if counts differ, stop descending
+
+    # and then recurse into children
+    for idx, (child1, child2) in enumerate(zip(kids1, kids2, strict=False), start=1):
+        errors.extend(
+            compare_elements(child1, child2, attr_whitelist, _path=f"{tag_path}[{idx}]")
+        )
+
+    return errors