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_license.py

@@ -2,51 +2,45 @@ import pytest
 
 from sqlalchemy.exc import IntegrityError
 
-from aurweb.db import create, query
-from aurweb.models.account_type import AccountType
+from aurweb import db
+from aurweb.models.account_type import USER_ID
 from aurweb.models.license import License
 from aurweb.models.package import Package
 from aurweb.models.package_base import PackageBase
 from aurweb.models.package_license import PackageLicense
 from aurweb.models.user import User
-from aurweb.testing import setup_test_db
 
 user = license = pkgbase = package = None
 
 
 @pytest.fixture(autouse=True)
-def setup():
+def setup(db_test):
     global user, license, pkgbase, package
 
-    setup_test_db("Users", "PackageBases", "Packages",
-                  "Licenses", "PackageLicenses")
+    with db.begin():
+        user = db.create(User, Username="test", Email="test@example.org",
+                         RealName="Test User", Passwd="testPassword",
+                         AccountTypeID=USER_ID)
+        license = db.create(License, Name="Test License")
 
-    account_type = query(AccountType,
-                         AccountType.AccountType == "User").first()
-    user = create(User, Username="test", Email="test@example.org",
-                  RealName="Test User", Passwd="testPassword",
-                  AccountType=account_type)
-
-    license = create(License, Name="Test License")
-    pkgbase = create(PackageBase, Name="test-package", Maintainer=user)
-    package = create(Package, PackageBase=pkgbase, Name=pkgbase.Name)
+    with db.begin():
+        pkgbase = db.create(PackageBase, Name="test-package", Maintainer=user)
+        package = db.create(Package, PackageBase=pkgbase, Name=pkgbase.Name)
 
 
 def test_package_license():
-    package_license = create(PackageLicense, Package=package, License=license)
+    with db.begin():
+        package_license = db.create(PackageLicense, Package=package,
+                                    License=license)
     assert package_license.License == license
     assert package_license.Package == package
 
 
 def test_package_license_null_package_raises_exception():
-    from aurweb.db import session
     with pytest.raises(IntegrityError):
-        create(PackageLicense, License=license)
-    session.rollback()
+        PackageLicense(License=license)
 
 
 def test_package_license_null_license_raises_exception():
-    from aurweb.db import session
     with pytest.raises(IntegrityError):
-        create(PackageLicense, Package=package)
-    session.rollback()
+        PackageLicense(Package=package)