section ticking covers the section

tests/test_plugins/test_guides_htmlimport.py

@@ -212,3 +212,14 @@ def test_an_empty_document_produces_a_named_guide_and_no_blocks():
     parsed = parse('')
     assert parsed['title'] == 'Untitled'
     assert parsed['blocks'] == []
+
+
+def test_a_heading_carries_its_rank():
+    """Ticking a section off has to cross out what belongs to it, and nothing
+    records that a sub-heading belongs to the heading above unless the level
+    travels with them."""
+    parsed = parse('<h1>T</h1><h2>Credentials</h2><p>Intro.</p>'
+                   '<h3>SFLD share</h3><p>Detail.</p><h2>Next</h2>')
+    headings = [(b['text'], b.get('level'))
+                for b in parsed['blocks'] if b['type'] == 'heading']
+    assert headings == [('Credentials', 2), ('SFLD share', 3), ('Next', 2)]