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_base_open(test_object, suffix, schema_source, schema_version):
"""Perform the actual opening of a database, then return it.
- `test_object`: The instance of the test class we're opening
a database for.
- `suffix`: The suffix to use on variable names when storing
open databases and auxiliary information.
- `schema_source`: Schema source code to use.
- `schema_version`: Version of the schema to use.
"""
db_name = 'db' + suffix
filename = getattr(test_object, 'filename' + suffix, None)
if filename is None:
filename = random_filename()
db = database.create(
filename = filename,
backend_name = 'durus',
backend_args = test_object.backend_args,
schema_source = schema_source,
schema_version = schema_version,
format = test_object.format,
)
else:
db = database.open(
filename = filename,
backend_name = 'durus',
backend_args = test_object.backend_args,
)
setattr(test_object, db_name, db)
setattr(test_object, 'filename' + suffix, filename)
return db
def backend_base_open(test_object, suffix, schema_source, schema_version):
"""Perform the actual opening of a database, then return it.
- `test_object`: The instance of the test class we're opening
a database for.
- `suffix`: The suffix to use on variable names when storing
open databases and auxiliary information.
- `schema_source`: Schema source code to use.
- `schema_version`: Version of the schema to use.
"""
db_name = 'db' + suffix
contents = TestMethods_CreatesDatabase.backend_db_contents(
test_object, suffix)
fp = StringIO(contents)
if len(contents) == 0:
db = database.create(
filename=None,
backend_name='schevo.store',
backend_args=dict(fp=fp, cache_size=100000),
schema_source=schema_source,
schema_version=schema_version,
format=test_object.format,
)
else:
db = database.open(
filename=None,
backend_name='schevo.store',
backend_args=dict(fp=fp, cache_size=100000),
)
setattr(test_object, db_name, db)
setattr(test_object, 'fp' + suffix, fp)
return db