1 files changed, 37 insertions, 0 deletions
diff --git a/tests/support/structural_diff.py b/tests/support/structural_diff.py
new file mode 100644
index 0000000..cea27d1
--- /dev/null
+++ b/tests/support/structural_diff.py
@@ -0,0 +1,37 @@
+import html.parser
+
+
+class Parser(html.parser.HTMLParser):
+    def __init__(self):
+        super().__init__()
+        self._stream = []
+
+    def handle_starttag(self, tag, attrs):
+        attrs = sorted(attrs, key=lambda x: x[0])
+        attrs = '|'.join([k[0] + ':' + k[1] for k in attrs])
+        self._stream.append(('<', tag, attrs))
+
+    def handle_endtag(self, tag):
+        self._stream.append(('>', tag, ''))
+
+    def handle_data(self, data):
+        self._stream.append(('_', data, ''))
+
+    @property
+    def stream(self):
+        return self._stream
+
+
+def _serialize(t):
+    parser = Parser()
+    parser.feed(t)
+    return parser.stream
+
+
+def structural_diff(a, b):
+    """Check if there is a structural difference between two HTML files."""
+    a_s = _serialize(a)
+    b_s = _serialize(b)
+
+    for e, f in zip(a_s, b_s):
+        assert e == f, f'Expected: {e}, found: {f}'