def test(self):
location = self.schemata
# Keep track of lack of failures.
failed = False
# Get the maximum schema version.
final_version = max(
schevo.schema.latest_version(location), self.max_version)
# For schema version N from 2 to maximum,
for N in xrange(2, final_version + 1):
# Read schema version N.
schema_N = schevo.schema.read(location, N)
# Create a database directly at version N.
fp_direct = StringIO()
db_direct = database.create(
filename=None,
backend_name='schevo.store',
backend_args=dict(fp=fp_direct, cache_size=100000),
schema_source=schema_N,
schema_version=N,
)
# Read schema version N - 1.
schema_N1 = schevo.schema.read(location, N - 1)
# Create a database at version N - 1.
fp_evolved = StringIO()
db_evolved = database.create(
filename=None,
backend_name='schevo.store',
backend_args=dict(fp=fp_evolved, cache_size=100000),
schema_source=schema_N1,
schema_version=N - 1,
)
# Evolve database to version N.
database.evolve(db_evolved, schema_N, N)
# Compare the databases.
is_equivalent = database.equivalent(db_direct, db_evolved)
# If failure,
if not is_equivalent:
if self.expected_failure:
# If failure expected, keep track of failure.
failed = True
else:
# If failure not expected, raise an exception.
raise Exception(
'Database created directly at version %i is not '
'the same as database created at version %i then '
'evolved to version %i.'
% (N, N - 1, N)
)
db_direct.close()
db_evolved.close()
# If failure expected, but no failures,
if self.expected_failure and not failed:
# Raise an exception.
raise Exception(
'Expected databases to be unequal at some point, but '
'they are all functionally equivalent.'
)
def backend_open(test_object):
"""Perform the actual opening of a database for a test
instance.
- `test_object`: The instance of the test class we're opening
a database for.
"""
format = test_object.format
use_db_cache = test_object._use_db_cache
db_name = 'db'
ex_name = 'ex'
fpv_name = 'fpv'
schema = test_object.schemata[-1]
version = test_object.schema_version
skip_evolution = test_object.skip_evolution
suffix = ''
cache_key = (format, version, skip_evolution, schema, suffix)
if (use_db_cache
and cache_key in _db_cache
and not hasattr(test_object, fpv_name)
):
db, fp = _db_cache[cache_key]
test_object.fp = fp
if not hasattr(test_object, 'db'):
db.backend.open()
db._reset_all()
test_object.db = db
else:
# Forget existing modules.
for m in module.MODULES:
module.forget(m)
if not skip_evolution:
# Open database with version 1.
db = test_object._base_open(suffix, test_object.schemata[0])
# Evolve to latest.
for i in xrange(1, len(test_object.schemata)):
schema_source = test_object.schemata[i]
database.evolve(db, schema_source, version=i+1)
else:
# Open database with target version.
db = test_object._base_open(
suffix, schema, schema_version=version)
if use_db_cache:
fp = test_object.fp
_db_cache[cache_key] = (db, fp)
_cached_dbs.add(db)
return db
def evolve(self, schema_source, version):
"""Evolve the database to a new schema source and version."""
db = self.reopen()
database.evolve(db, schema_source, version)