Adding basic docs endpoint sanity test

demo/tests.py

@@ -64,3 +64,14 @@ def test_menu_links(url: str):
 
 
 # TODO tests for forms, including submission
+
+def test_doc():
+    r = client.get('/docs')
+    assert r.status_code == 200, r.text
+    html_content = r.text
+    title_start = html_content.find("<title>") + len("<title>")
+    title_end = html_content.find("</title>")
+    title = html_content[title_start:title_end]
+    assert title == 'FastAPI - Swagger UI'
+    assert r.headers.get('content-type') == 'text/html; charset=utf-8'
+