Parallelize the unit tests

bin/tests

@@ -6,7 +6,7 @@ set -e
 # correct.
 export LC_ALL="${ENCODING:-en_US.UTF-8}"
 export LANG="${ENCODING:-en_US.UTF-8}"
-
+export COVERAGE_PROCESS_START="$(pwd)/pyproject.toml"
 COMMAND_ARGS="$@"
 
 # Test the postgres connection
@@ -38,5 +38,6 @@ mkdir -p warehouse/static/dist/
 
 # Actually run our tests.
 python -m coverage run -m pytest --strict-markers $COMMAND_ARGS
+python -m coverage combine
 python -m coverage html --show-contexts
 python -m coverage report -m --fail-under 100

docker-compose.yml

@@ -94,6 +94,9 @@ services:
       - ./htmlcov:/opt/warehouse/src/htmlcov:z
       - ./setup.cfg:/opt/warehouse/src/setup.cfg:z
       - ./pyproject.toml:/opt/warehouse/src/pyproject.toml:z
+      # Site customization shim to enable multiprocess coverage collection in tests.
+      # See: https://coverage.readthedocs.io/en/latest/subprocess.html
+      - ./sitecustomize.py:/opt/warehouse/src/sitecustomize.py:z
       - packages:/var/opt/warehouse/packages
       - packages-archive:/var/opt/warehouse/packages-archive
       - sponsorlogos:/var/opt/warehouse/sponsorlogos

pyproject.toml

@@ -17,6 +17,9 @@ omit = [
   # And again, tiny shim code.
   "warehouse/celery.py",
 ]
+# We run multiple processes in parallel, so we need to make sure that we don't
+# write to the same file at the same time.
+parallel = true
 
 [tool.coverage.report]
 exclude_lines = [
@@ -87,6 +90,7 @@ addopts = [
   "--disable-socket",
   "--allow-hosts=localhost,::1,notdatadog,stripe",
   "--durations=20",
+  "--numprocesses=auto",
 ]
 cache_dir = "dev/.pytest_cache"
 norecursedirs = ['build', 'dist', 'node_modules', '*.egg-info', '.state requirements']

requirements/tests.in

@@ -7,6 +7,7 @@ pytest-icdiff
 pytest-postgresql>=3.1.3,<7.0.0
 pytest-randomly
 pytest-socket
+pytest-xdist
 pytz
 responses>=0.5.1
 webtest

requirements/tests.txt

@@ -158,6 +158,10 @@ coverage==7.5.4 \
     --hash=sha256:e564c2cf45d2f44a9da56f4e3a26b2236504a496eb4cb0ca7221cd4cc7a9aca9 \
     --hash=sha256:ed550e7442f278af76d9d65af48069f1fb84c9f745ae249c1a183c1e9d1b025c
     # via -r requirements/tests.in
+execnet==2.0.2 \
+    --hash=sha256:88256416ae766bc9e8895c76a87928c0012183da3cc4fc18016e6f050e025f41 \
+    --hash=sha256:cc59bc4423742fd71ad227122eb0dd44db51efb3dc4095b45ac9a08c770096af
+    # via pytest-xdist
 factory-boy==3.3.0 \
     --hash=sha256:a2cdbdb63228177aa4f1c52f4b6d83fab2b8623bf602c7dedd7eb83c0f69c04c \
     --hash=sha256:bc76d97d1a65bbd9842a6d722882098eb549ec8ee1081f9fb2e8ff29f0c300f1
@@ -238,6 +242,7 @@ pytest==8.2.2 \
     #   pytest-postgresql
     #   pytest-randomly
     #   pytest-socket
+    #   pytest-xdist
 pytest-icdiff==0.9 \
     --hash=sha256:13aede616202e57fcc882568b64589002ef85438046f012ac30a8d959dac8b75 \
     --hash=sha256:efee0da3bd1b24ef2d923751c5c547fbb8df0a46795553fba08ef57c3ca03d82
@@ -254,6 +259,10 @@ pytest-socket==0.7.0 \
     --hash=sha256:71ab048cbbcb085c15a4423b73b619a8b35d6a307f46f78ea46be51b1b7e11b3 \
     --hash=sha256:7e0f4642177d55d317bbd58fc68c6bd9048d6eadb2d46a89307fa9221336ce45
     # via -r requirements/tests.in
+pytest-xdist==3.5.0 \
+    --hash=sha256:cbb36f3d67e0c478baa57fa4edc8843887e0f6cfc42d677530a36d7472b32d8a \
+    --hash=sha256:d075629c7e00b611df89f490a5063944bee7a4362a5ff11c7cc7824a03dfce24
+    # via -r requirements/tests.in
 python-dateutil==2.9.0.post0 \
     --hash=sha256:37dd54208da7e1cd875388217d5e00ebd4179249f90fb72437e91a35459a0ad3 \
     --hash=sha256:a8b2bc7bffae282281c8140a97d3aa9c14da0b136dfe83f850eea9a5f7470427

sitecustomize.py

@@ -0,0 +1,21 @@
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Site customization shim to enable multiprocess coverage collection in tests.
+# See: https://coverage.readthedocs.io/en/latest/subprocess.html
+
+try:
+    import coverage
+
+    coverage.process_startup()
+except ImportError:
+    pass

tests/conftest.py

@@ -249,12 +249,12 @@ def cli():
 
 
 @pytest.fixture(scope="session")
-def database(request):
+def database(request, worker_id):
     config = get_config(request)
     pg_host = config.get("host")
     pg_port = config.get("port") or os.environ.get("PGPORT", 5432)
     pg_user = config.get("user")
-    pg_db = config.get("db", "tests")
+    pg_db = f"tests-{worker_id}"
     pg_version = config.get("version", 16.1)
 
     janitor = DatabaseJanitor(