Run xdist tests runs with -n auto flag - closes #1081

    Make sure we attempt to run tests on not used port for xdist - closes #872

.github/workflows/dockerised-postgres.yml

@@ -57,7 +57,7 @@ jobs:
         uses: fizyk/actions-reuse/.github/actions/[email protected]
         with:
           python-version: ${{ matrix.python-version }}
-          command: pytest -n 0 -k docker --postgresql-host=localhost --postgresql-port 5433 --postgresql-password=postgres --cov-report=xml:coverage-docker.xml
+          command: pytest -n 0 --max-worker-restart 0 -k docker --postgresql-host=localhost --postgresql-port 5433 --postgresql-password=postgres --cov-report=xml:coverage-docker.xml
       - name: Upload coverage to Codecov
         uses: codecov/[email protected]
         with:

.github/workflows/single-postgres.yml

@@ -56,12 +56,12 @@ jobs:
         uses: fizyk/actions-reuse/.github/actions/[email protected]
         with:
           python-version: ${{ matrix.python-version }}
-          command: py.test -svv -n 0 --postgresql-exec="/usr/lib/postgresql/${{ inputs.postgresql }}/bin/pg_ctl" -k "not docker" --cov-report=xml
+          command: py.test -svv -p no:xdist --postgresql-exec="/usr/lib/postgresql/${{ inputs.postgresql }}/bin/pg_ctl" -k "not docker" --cov-report=xml
       - name: Run xdist test
         uses: fizyk/actions-reuse/.github/actions/[email protected]
         with:
           python-version: ${{ matrix.python-version }}
-          command: py.test -n 1 --postgresql-exec="/usr/lib/postgresql/${{ inputs.postgresql }}/bin/pg_ctl" -k "not docker" --cov-report=xml:coverage-xdist.xml
+          command: py.test -n auto --max-worker-restart 0 --postgresql-exec="/usr/lib/postgresql/${{ inputs.postgresql }}/bin/pg_ctl" -k "not docker" --cov-report=xml:coverage-xdist.xml
       - uses: actions/upload-artifact@v4
         if: failure()
         with:

newsfragments/1081.misc.rst

@@ -0,0 +1 @@
+Run xdist test with -n auto, turn off xdist for xdist-less runs

pyproject.toml

@@ -58,7 +58,7 @@ namespaces = false
 
 [tool.pytest.ini_options]
 xfail_strict=true
-addopts = "--max-worker-restart=0 --showlocals --verbose --cov"
+addopts = "--showlocals --verbose --cov"
 testpaths = "tests"
 pytester_example_dir = "tests/examples"
 norecursedirs = "examples"

pytest_postgresql/factories/process.py

@@ -21,7 +21,7 @@
 import platform
 import subprocess
 from pathlib import Path
-from typing import Callable, Iterator, List, Optional, Tuple, Union
+from typing import Callable, Iterator, List, Optional, Tuple, Union, Iterable
 
 import port_for
 import pytest
@@ -54,9 +54,9 @@ def _pg_exe(executable: Optional[str], config: PostgresqlConfigDict) -> str:
     return postgresql_ctl
 
 
-def _pg_port(port: Optional[PortType], config: PostgresqlConfigDict) -> int:
+def _pg_port(port: Optional[PortType], config: PostgresqlConfigDict, excluded_ports: Iterable[int]) -> int:
     """User specified port, otherwise find an unused port from config."""
-    pg_port = get_port(port) or get_port(config["port"])
+    pg_port = get_port(port, excluded_ports) or get_port(config["port"], excluded_ports)
     assert pg_port is not None
     return pg_port
 
@@ -122,7 +122,29 @@ def postgresql_proc_fixture(
         pg_dbname = dbname or config["dbname"]
         pg_load = load or config["load"]
         postgresql_ctl = _pg_exe(executable, config)
-        pg_port = _pg_port(port, config)
+        port_path = tmp_path_factory.getbasetemp()
+        if hasattr(request.config, "workerinput"):
+            port_path = tmp_path_factory.getbasetemp().parent
+
+        pg_port = 0
+        n = 0
+        used_ports: set[int] = set()
+        while True:
+            try:
+                pg_port = _pg_port(port, config, used_ports)
+                if pg_port in used_ports:
+                    # if it's marked as already used, then it means it's not randomly selected. No point in looking further.
+                    break
+                used_ports.add(pg_port)
+                with (port_path / f"postgresql-{pg_port}.port").open("x") as port_file:
+                    port_file.write(f"pg_port {pg_port}\n")
+                break
+            except FileExistsError:
+                if n >= 5:
+                    # Well, end user will get AlreadyRunning error bit later which is more informative, than we can give here.
+                    break
+                n += 1
+
         tmpdir = tmp_path_factory.mktemp(f"pytest-postgresql-{request.fixturename}")
         datadir, logfile_path = _prepare_dir(tmpdir, str(pg_port))
 

tests/test_executor.py

@@ -79,7 +79,7 @@ def test_executor_init_with_password(
     config = get_config(request)
     monkeypatch.setenv("LC_ALL", locale)
     pg_exe = process._pg_exe(None, config)
-    port = process._pg_port(-1, config)
+    port = process._pg_port(-1, config, [])
     tmpdir = tmp_path_factory.mktemp(f"pytest-postgresql-{request.node.name}")
     datadir, logfile_path = process._prepare_dir(tmpdir, port)
     executor = PostgreSQLExecutor(
@@ -103,7 +103,7 @@ def test_executor_init_bad_tmp_path(
     r"""Test init with \ and space chars in the path."""
     config = get_config(request)
     pg_exe = process._pg_exe(None, config)
-    port = process._pg_port(-1, config)
+    port = process._pg_port(-1, config, [])
     tmpdir = tmp_path_factory.mktemp(f"pytest-postgresql-{request.node.name}") / r"a bad\path/"
     tmpdir.mkdir(exist_ok=True)
     datadir, logfile_path = process._prepare_dir(tmpdir, port)

tests/test_template_database.py

@@ -17,7 +17,7 @@
     dbname="stories_templated",
 )
 
-
+@pytest.mark.xdist_group(name="template_database")
 @pytest.mark.parametrize("_", range(5))
 def test_template_database(postgresql_template: Connection, _: int) -> None:
     """Check that the database structure gets recreated out of a template."""