Revamp development workflow

.gitignore

@@ -41,6 +41,7 @@ pip-delete-this-directory.txt
 # Unit test / coverage reports
 htmlcov/
 .tox/
+.nox/
 .coverage
 .cache
 .pytest_cache/

.travis.yml

@@ -1,40 +1,63 @@
-language: python
-sudo: false
-python:
-- '2.7'
-- '3.4'
-- '3.5'
+# System information
+os: linux
 addons:
   postgresql: "9.3"
+services:
+  - redis
 
-cache:
-  directories:
-  - $HOME/.pip-cache/
+language: python
+python: 3.5
+cache: pip
+
+# Use a two-stage approach, to minimize CI time on failures.
+stages:
+- primary
+- secondary
+
+env: DJANGO_SETTINGS_MODULE="settings.test_settings"
+
+jobs:
+  include:
+    # Basic Checks
+    - stage: primary
+      env: NOXSESSION=lint-3.5
+    - env: NOXSESSION=test-3.5
+    # - env: NOXSESSION=docs
+
+    - stage: secondary
+      env: NOXSESSION=test-3.6
+      python: 3.6
+    ## Commented out, due to: Pinned psycopg2 not being compatible.
+    # - env: NOXSESSION=test-3.7
+    #   python: 3.7
+    ## Commented out, due to:
+    ## 1. Pinned celery version not being compatible.
+    ## 2. Pinned Django version not being compatible with newer celery.
+    ## 3. Current codebase needing quite a few changes to be compatible
+    ##    with newer Django.
+    # - env: NOXSESSION=test-3.7
+    #   python: 3.7
 
 install:
-  - pip install pip==9.0.1
-  - pip install -r requirements-dev.txt --allow-all-external
-  - pip install coveralls
-  - pip install --upgrade pytest
+  # Get the latest pip
+  - python -m pip install --upgrade pip
+  # Reinstall pip, using the latest pip
+  - python -m pip install --force-reinstall pip
 
-env:
-  - DJANGO_SETTINGS_MODULE="settings.test_settings"
+  # Install the CI dependencies
+  - python -m pip install celery==3.1.20  # pin from requirements.txt
+  - python -m pip install nox
+  - python -m pip install coveralls
 
+before_script:
+  - celery -A junction worker -l info &
 script:
-- flake8
-- pytest --cov -v --tb=native
-- coverage report -m
-
+  - nox
 after_success:
-  coveralls
+  - coveralls
 
 notifications:
   email:
     on_success: change  # [always|never|change]
     on_failure: always  # [always|never|change]
 
-services:
-  - redis-server
-
-before_script:
-  - celery -A junction worker -l info &

junction/proposals/views.py

@@ -183,7 +183,7 @@ def detail_proposal(request, conference_slug, slug, hashid=None):
         proposal = get_object_or_404(Proposal, slug=slug, conference=conference)
         return HttpResponseRedirect(proposal.get_absolute_url())
 
-    if proposal.deleted == True:
+    if proposal.deleted:
         raise Http404("404")
 
     # Here we have obtained the proposal that we want to display.
@@ -295,7 +295,6 @@ def proposals_to_review(request, conference_slug):
     if not permissions.is_proposal_reviewer(request.user, conference):
         raise PermissionDenied
 
-
     proposals_qs = Proposal.objects.select_related(
         'proposal_type', 'proposal_section', 'conference', 'author',
     ).filter(conference=conference).filter(status=ProposalStatus.PUBLIC).order_by('created_at')

noxfile.py

@@ -0,0 +1,45 @@
+"""Automation using nox.
+"""
+
+import nox
+
+
+@nox.session(python=["3.5", "3.6", "3.7", "3.8"])
+def test(session):
+    session.install("-r", "requirements.txt")
+    session.install("-r", "tools/requirements-test.txt")
+
+    session.run("pytest", "--cov", "-v", "--tb=native")
+    session.run("coverage", "report", "-m")
+
+
+@nox.session(python=["3.5", "3.6", "3.7", "3.8"])
+def lint(session):
+    session.install("-r", "tools/requirements-lint.txt")
+    session.run(
+        "flake8",
+        "--max-complexity=24",
+        "--statistics",
+        "--benchmark",
+        "--ignore=E5,F4",
+        "junction/"
+    )
+    # TODO: Add tests/ to the arguments above.
+
+
+@nox.session(python="3.5")
+def docs(session):
+    session.install("-r", "tools/requirements-docs.txt")
+
+    def get_sphinx_build_command(kind):
+        return [
+            "sphinx-build",
+            "-W",
+            "-c", "docs/",  # see note above
+            "-d", "docs/build/_doctrees/" + kind,
+            "-b", kind,
+            "docs/" + kind,
+            "docs/_build/" + kind,
+        ]
+
+    session.run(*get_sphinx_build_command("html"))