Remove the lxml dependency.

Replace lxml with html.parser for the structural-diff.

3 files changed, 31 insertions, 13 deletions

diff --git a/requirements.txt b/requirements.txt
index be5330a8..05a0b12b 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -5,4 +5,3 @@ pyflakes
 pylint
 tox
 wcag-contrast-ratio
-lxml
diff --git a/tests/support/structural_diff.py b/tests/support/structural_diff.py
index d2e4d7f2..cea27d10 100644
--- a/tests/support/structural_diff.py
+++ b/tests/support/structural_diff.py
@@ -1,17 +1,37 @@
-import lxml.html
-import lxml.etree
-import pytest
+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):
-    for a, e in lxml.etree.iterwalk(t, events=("start", "end"),):
-        text = e.text.strip() if e.text else ""
-        yield (a, e.tag, repr(text), ', '.join([k[0]+':'+k[1] for k in sorted(e.attrib.items(), key = lambda x: x[0])]))
+    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(lxml.html.fromstring(a))
-    b_s = _serialize(lxml.html.fromstring(b))
-    
+    a_s = _serialize(a)
+    b_s = _serialize(b)
+
     for e, f in zip(a_s, b_s):
-        print(e, f)
-        assert e == f
\ No newline at end of file
+        assert e == f, f'Expected: {e}, found: {f}'
diff --git a/tox.ini b/tox.ini
index 3d6dac4c..dc0a5be5 100644
--- a/tox.ini
+++ b/tox.ini
@@ -6,7 +6,6 @@ deps =
     pytest
     pytest-cov
     wcag-contrast-ratio
-    lxml
 commands = pytest {posargs}