Handling overridden css_files/html_static_path.

Users setting those two variables in their conf.py broke SCVersioning.
Handling this by injecting SCVersioning objects during html-page-context
Sphinx API hook.

Fixes #23

README.rst

@@ -44,6 +44,12 @@ Changelog
 
 This project adheres to `Semantic Versioning <http://semver.org/>`_.
 
+Unreleased
+----------
+
+Fixed
+    * banner.css being overridden by conf.py: https://github.com/Robpol86/sphinxcontrib-versioning/issues/23
+
 2.1.3 - 2016-08-24
 ------------------
 

sphinxcontrib/versioning/sphinx_.py

@@ -1,7 +1,5 @@
 """Interface with Sphinx."""
 
-from __future__ import print_function
-
 import logging
 import multiprocessing
 import os
@@ -18,6 +16,7 @@
 from sphinxcontrib.versioning.versions import Versions
 
 SC_VERSIONING_VERSIONS = list()  # Updated after forking.
+STATIC_DIR = os.path.join(os.path.dirname(__file__), '_static')
 
 
 class EventHandlers(object):
@@ -116,6 +115,13 @@ def html_page_context(cls, app, pagename, templatename, context, doctree):
         if cls.SHOW_BANNER and 'body' in context:
             parsed = app.builder.templates.render('banner.html', context)
             context['body'] = parsed + context['body']
+            # Handle overridden css_files.
+            css_files = context.setdefault('css_files', list())
+            if '_static/banner.css' not in css_files:
+                css_files.append('_static/banner.css')
+            # Handle overridden html_static_path.
+            if STATIC_DIR not in app.config.html_static_path:
+                app.config.html_static_path.append(STATIC_DIR)
 
 
 def setup(app):
@@ -130,7 +136,7 @@ def setup(app):
     app.add_config_value('sphinxcontrib_versioning_versions', SC_VERSIONING_VERSIONS, 'html')
 
     # Needed for banner.
-    app.config.html_static_path.append(os.path.join(os.path.dirname(__file__), '_static'))
+    app.config.html_static_path.append(STATIC_DIR)
     app.add_stylesheet('banner.css')
 
     # Tell Sphinx which config values can be set by the user.

tests/test__main__/test_main_build_scenarios.py

@@ -600,6 +600,37 @@ def test_banner(banner, local_docs, run, disable_banner):
            'an old version of Python. The main version is stable')
 
 
+def test_banner_css_override(banner, local_docs, run):
+    """Test the banner CSS being present even if user overrides html_context['css_files'].
+
+    :param banner: conftest fixture.
+    :param local_docs: conftest fixture.
+    :param run: conftest fixture.
+    """
+    local_docs.join('conf.py').write("html_context = {'css_files': ['_static/theme_overrides.css']}\n", mode='a')
+    local_docs.join('conf.py').write("html_static_path = ['_static']\n", mode='a')
+    run(local_docs, ['git', 'commit', '-am', 'Setting override.'])
+    run(local_docs, ['git', 'checkout', '-b', 'other', 'master'])
+    run(local_docs, ['git', 'push', 'origin', 'master', 'other'])
+
+    # Run.
+    destination = local_docs.ensure_dir('..', 'destination')
+    output = run(local_docs, ['sphinx-versioning', 'build', '.', str(destination), '--show-banner'])
+    assert 'Traceback' not in output
+    assert 'Disabling banner.' not in output
+    assert 'Banner main ref is: master' in output
+
+    # Check banner.
+    banner(destination.join('master', 'contents.html'), None)  # No banner in main ref.
+    banner(destination.join('other', 'contents.html'), '../master/contents.html',
+           'the development version of Python. The main version is master')
+
+    # Check CSS.
+    contents = destination.join('other', 'contents.html').read()
+    assert 'rel="stylesheet" href="_static/banner.css"' in contents
+    assert destination.join('other', '_static', 'banner.css').check(file=True)
+
+
 def test_error_bad_path(tmpdir, run):
     """Test handling of bad paths.