change(aurweb): add parallel tests and improve aurweb.db

This change utilizes pytest-xdist to perform a multiproc test
run and reworks aurweb.db's code. We no longer use a global
engine, session or Session, but we now use a memo of engines
and sessions as they are requested, based on the PYTEST_CURRENT_TEST
environment variable, which is available during testing.

Additionally, this change strips several SQLite components
out of the Python code-base.

SQLite is still compatible with PHP and sharness tests, but
not with our FastAPI implementation.

More changes:
------------
- Remove use of aurweb.db.session global in other code.
- Use new aurweb.db.name() dynamic db name function in env.py.
- Added 'addopts' to pytest.ini which utilizes multiprocessing.
    - Highly recommended to leave this be or modify `-n auto` to
      `-n {cpu_threads}` where cpu_threads is at least 2.

Signed-off-by: Kevin Morris <kevr@0cost.org>

test/test_package_relation.py

@@ -1,103 +1,63 @@
 import pytest
 
-from sqlalchemy.exc import IntegrityError, OperationalError
+from sqlalchemy.exc import IntegrityError
 
 from aurweb import db
-from aurweb.db import create, query
-from aurweb.models.account_type import AccountType
+from aurweb.models.account_type import USER_ID
 from aurweb.models.package import Package
 from aurweb.models.package_base import PackageBase
 from aurweb.models.package_relation import PackageRelation
-from aurweb.models.relation_type import RelationType
+from aurweb.models.relation_type import CONFLICTS_ID, PROVIDES_ID, REPLACES_ID
 from aurweb.models.user import User
-from aurweb.testing import setup_test_db
 
 user = pkgbase = package = None
 
 
 @pytest.fixture(autouse=True)
-def setup():
+def setup(db_test):
     global user, pkgbase, package
 
-    setup_test_db("Users", "PackageBases", "Packages", "PackageRelations")
-
-    account_type = query(AccountType,
-                         AccountType.AccountType == "User").first()
-
     with db.begin():
-        user = create(User, Username="test", Email="test@example.org",
-                      RealName="Test User", Passwd="testPassword",
-                      AccountType=account_type)
-        pkgbase = create(PackageBase,
-                         Name="test-package",
-                         Maintainer=user)
-        package = create(Package,
-                         PackageBase=pkgbase,
-                         Name=pkgbase.Name,
-                         Description="Test description.",
-                         URL="https://test.package")
+        user = db.create(User, Username="test", Email="test@example.org",
+                         RealName="Test User", Passwd="testPassword",
+                         AccountTypeID=USER_ID)
+        pkgbase = db.create(PackageBase,
+                            Name="test-package",
+                            Maintainer=user)
+        package = db.create(Package,
+                            PackageBase=pkgbase,
+                            Name=pkgbase.Name,
+                            Description="Test description.",
+                            URL="https://test.package")
 
 
 def test_package_relation():
-    conflicts = query(RelationType, RelationType.Name == "conflicts").first()
-
     with db.begin():
-        pkgrel = create(PackageRelation, Package=package,
-                        RelationType=conflicts,
-                        RelName="test-relation")
+        pkgrel = db.create(PackageRelation, Package=package,
+                           RelTypeID=CONFLICTS_ID,
+                           RelName="test-relation")
+
     assert pkgrel.RelName == "test-relation"
     assert pkgrel.Package == package
-    assert pkgrel.RelationType == conflicts
-    assert pkgrel in conflicts.package_relations
     assert pkgrel in package.package_relations
 
-    provides = query(RelationType, RelationType.Name == "provides").first()
     with db.begin():
-        pkgrel.RelationType = provides
-    assert pkgrel.RelName == "test-relation"
-    assert pkgrel.Package == package
-    assert pkgrel.RelationType == provides
-    assert pkgrel in provides.package_relations
-    assert pkgrel in package.package_relations
+        pkgrel.RelTypeID = PROVIDES_ID
 
-    replaces = query(RelationType, RelationType.Name == "replaces").first()
     with db.begin():
-        pkgrel.RelationType = replaces
-    assert pkgrel.RelName == "test-relation"
-    assert pkgrel.Package == package
-    assert pkgrel.RelationType == replaces
-    assert pkgrel in replaces.package_relations
-    assert pkgrel in package.package_relations
+        pkgrel.RelTypeID = REPLACES_ID
 
 
 def test_package_relation_null_package_raises_exception():
-    conflicts = query(RelationType, RelationType.Name == "conflicts").first()
-    assert conflicts is not None
-
     with pytest.raises(IntegrityError):
-        with db.begin():
-            create(PackageRelation,
-                   RelationType=conflicts,
-                   RelName="test-relation")
-    db.rollback()
+        PackageRelation(RelTypeID=CONFLICTS_ID, RelName="test-relation")
 
 
 def test_package_relation_null_relation_type_raises_exception():
     with pytest.raises(IntegrityError):
-        with db.begin():
-            create(PackageRelation,
-                   Package=package,
-                   RelName="test-relation")
-    db.rollback()
+        PackageRelation(Package=package, RelName="test-relation")
 
 
 def test_package_relation_null_relname_raises_exception():
-    depends = query(RelationType, RelationType.Name == "conflicts").first()
-    assert depends is not None
-
-    with pytest.raises((OperationalError, IntegrityError)):
-        with db.begin():
-            create(PackageRelation,
-                   Package=package,
-                   RelationType=depends)
-    db.rollback()
+    with pytest.raises(IntegrityError):
+        PackageRelation(Package=package, RelTypeID=CONFLICTS_ID)