Build HTML Tidy, validate homepage HTML in tests

Adds the HTML Tidy library to the dev version, along with the pytidylib
wrapper for it, and a couple of tests that use it to validate the HTML
of the home page.

Includes a fix to the GitLab "Planned features" link that Tidy considers
invalid because it includes some un-encoded characters.

salt/salt/tidy/init.sls

@@ -0,0 +1,25 @@
+{% set tidy_version = '5.7.28' %}
+
+unpack-tidy:
+  archive.extracted:
+    - name: /tmp/tidy-{{ tidy_version }}
+    - source:
+      - https://github.com/htacg/tidy-html5/archive/{{ tidy_version }}.tar.gz
+    - source_hash: sha256=5caa2c769204f506e24ea4986a45abe23f71d14f0fe968314f20065f342ffdba
+    - unless: /usr/local/bin/tidy --version | grep 'version {{ tidy_version }}'
+    - options: --strip-components=1
+    - enforce_toplevel: False
+
+install-tidy:
+  pkg.installed:
+    - pkgs:
+      - build-essential
+  cmd.run:
+    - cwd: /tmp/tidy-{{ tidy_version }}/build/cmake
+    - names:
+      - cmake ../.. -DCMAKE_BUILD_TYPE=Release
+      - make
+      - make install
+      - ldconfig
+    - onchanges:
+      - archive: unpack-tidy

salt/salt/top.sls

@@ -30,6 +30,7 @@ base:
     - development
     - prometheus
     - nodejs
+    - tidy
   'prod':
     - nginx.shortener-config
     - nginx.static-sites-config

tildes/requirements-dev.in

@@ -6,5 +6,6 @@ prospector
 pyramid-debugtoolbar
 pytest
 pytest-mock
+pytidylib
 testing.redis
 webtest

tildes/requirements-dev.txt

@@ -81,6 +81,7 @@ pytest-mock==3.2.0
 pytest==6.0.0
 python-dateutil==2.8.1
 python-editor==1.0.4      # via alembic
+pytidylib==0.3.2
 pyyaml==5.3.1
 qrcode==6.1
 redis==3.5.3

tildes/tests/webtests/test_valid_html5.py

@@ -0,0 +1,20 @@
+# Copyright (c) 2020 Tildes contributors <code@tildes.net>
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+from tidylib import tidy_document
+
+
+def test_homepage_tidy_loggedout(webtest_loggedout):
+    """Validate HTML5 using Tidy on the Tildes homepage, logged out."""
+    homepage = webtest_loggedout.get("/")
+    _document, errors = tidy_document(homepage.body)
+
+    assert not errors
+
+
+def test_homepage_tidy_loggedin(webtest):
+    """Validate HTML5 using Tidy on the Tildes homepage, logged in."""
+    homepage = webtest.get("/")
+    _document, errors = tidy_document(homepage.body)
+
+    assert not errors

tildes/tildes/templates/base.jinja2

@@ -130,7 +130,7 @@
     <li class="site-footer-link"><a href="https://blog.tildes.net">Blog</a></li>
     <li class="site-footer-link"><a href="https://docs.tildes.net/contact">Contact</a></li>
     <li class="site-footer-link"><a href="https://gitlab.com/tildes/tildes">Source code</a></li>
-    <li class="site-footer-link"><a href="https://gitlab.com/tildes/tildes/issues?label_name[]=Feature+Request&label_name[]=Stage%3A%3AAccepted&scope=all&sort=priority&state=opened">Planned features</a> / <a href="https://gitlab.com/tildes/tildes/issues">All issues</a></li>
+    <li class="site-footer-link"><a href="https://gitlab.com/tildes/tildes/issues?label_name%5B%5D=Feature+Request&amp;label_name%5B%5D=Stage%3A%3AAccepted&amp;scope=all&amp;sort=priority&amp;state=opened">Planned features</a> / <a href="https://gitlab.com/tildes/tildes/issues">All issues</a></li>
     <li class="site-footer-link"><a href="https://docs.tildes.net/policies/privacy-policy">Privacy policy</a></li>
     <li class="site-footer-link"><a href="https://docs.tildes.net/policies/terms-of-use">Terms of use</a></li>
   </ul>