Refactoring part 3: moving config classes to a new 'config' module.

src/config.py

@@ -0,0 +1,67 @@
+import codecs
+import os
+
+class Config(object):
+
+    DB_VERSION_TABLE = "__db_version__"
+
+    def __init__(self):
+        self._config = {}
+
+    def __repr__(self):
+        return str(self._config)
+
+    def get(self, config_key):
+        try:
+            return self._config[config_key]
+        except KeyError:
+            raise Exception("invalid configuration key ('%s')" % config_key)
+
+    def put(self, config_key, config_value):
+        if config_key in self._config:
+            raise Exception("the configuration key '%s' already exists and you cannot override any configuration" % config_key)
+        self._config[config_key] = config_value
+
+    def _parse_migrations_dir(self, dirs):
+        abs_dirs = []
+        for dir in dirs.split(':'):
+            abs_dirs.append(os.path.abspath(dir))
+        return abs_dirs
+
+class FileConfig(Config):
+
+    def __init__(self, config_file="simple-db-migrate.conf"):
+        self._config = {}
+
+        # read configurations
+        try:
+            f = codecs.open(config_file, "rU", "utf-8")
+            exec(f.read())
+        except IOError:
+            raise Exception("%s: file not found" % config_file)
+        else:
+            f.close()
+
+        try:
+            self.put("db_host", HOST)
+            self.put("db_user", USERNAME)
+            self.put("db_password", PASSWORD)
+            self.put("db_name", DATABASE)
+            self.put("db_version_table", self.DB_VERSION_TABLE)
+            self.put("migrations_dir", self._parse_migrations_dir(MIGRATIONS_DIR))
+        except NameError, e:
+            raise Exception("config file error: " + str(e))
+
+class InPlaceConfig(Config):
+
+    def __init__(self, db_host, db_user, db_password, db_name, migrations_dir, db_version_table=''):
+        if not db_version_table or db_version_table == '':
+            db_version_table = self.DB_VERSION_TABLE
+        self._config = {
+            "db_host": db_host,
+            "db_user": db_user,
+            "db_password": db_password,
+            "db_name": db_name,
+            "db_version_table": db_version_table,
+            "migrations_dir": self._parse_migrations_dir(migrations_dir)
+        }

src/core.py

@@ -3,72 +3,6 @@
 import os
 import shutil
 import re
-
-# TODO: move to a config module (the 3 config classes below)
-class Config(object):
-
-    DB_VERSION_TABLE = "__db_version__"
-
-    def __init__(self):
-        self._config = {}
-
-    def __repr__(self):
-        return str(self._config)
-
-    def get(self, config_key):
-        try:
-            return self._config[config_key]
-        except KeyError:
-            raise Exception("invalid configuration key ('%s')" % config_key)
-
-    def put(self, config_key, config_value):
-        if config_key in self._config:
-            raise Exception("the configuration key '%s' already exists and you cannot override any configuration" % config_key)
-        self._config[config_key] = config_value
-
-    def _parse_migrations_dir(self, dirs):
-        abs_dirs = []
-        for dir in dirs.split(':'):
-            abs_dirs.append(os.path.abspath(dir))
-        return abs_dirs
-
-class FileConfig(Config):
-
-    def __init__(self, config_file="simple-db-migrate.conf"):
-        self._config = {}
-
-        # read configurations
-        try:
-            f = codecs.open(config_file, "rU", "utf-8")
-            exec(f.read())
-        except IOError:
-            raise Exception("%s: file not found" % config_file)
-        else:
-            f.close()
-
-        try:
-            self.put("db_host", HOST)
-            self.put("db_user", USERNAME)
-            self.put("db_password", PASSWORD)
-            self.put("db_name", DATABASE)
-            self.put("db_version_table", self.DB_VERSION_TABLE)
-            self.put("migrations_dir", self._parse_migrations_dir(MIGRATIONS_DIR))
-        except NameError, e:
-            raise Exception("config file error: " + str(e))
-
-class InPlaceConfig(Config):
-
-    def __init__(self, db_host, db_user, db_password, db_name, migrations_dir, db_version_table=''):
-        if not db_version_table or db_version_table == '':
-            db_version_table = self.DB_VERSION_TABLE
-        self._config = {
-            "db_host": db_host,
-            "db_user": db_user,
-            "db_password": db_password,
-            "db_name": db_name,
-            "db_version_table": db_version_table,
-            "migrations_dir": self._parse_migrations_dir(migrations_dir)
-        }
 
 class Migration(object):
 

tests/config_test.py

@@ -0,0 +1,133 @@
+from test import *
+from config import *
+import codecs
+import unittest
+
+class ConfigTest(unittest.TestCase):
+
+    def test_it_should_parse_migrations_dir_with_one_relative_dir(self):
+        config = Config()
+        dirs = config._parse_migrations_dir('.')
+        assert len(dirs) == 1
+        assert dirs[0] == os.path.abspath('.')
+
+    def test_it_should_parse_migrations_dir_with_two_relative_dirs(self):
+        config = Config()
+        dirs = config._parse_migrations_dir('test:migrations:./a/relative/path:another/path')
+        assert len(dirs) == 4
+        assert dirs[0] == os.path.abspath('test')
+        assert dirs[1] == os.path.abspath('migrations')
+        assert dirs[2] == os.path.abspath('./a/relative/path')
+        assert dirs[3] == os.path.abspath('another/path')
+
+    def test_it_should_parse_migrations_dir_with_one_absolute_dir(self):
+        config = Config()
+        dirs = config._parse_migrations_dir(os.path.abspath('.'))
+        assert len(dirs) == 1
+        assert dirs[0] == os.path.abspath('.')
+
+    def test_it_should_parse_migrations_dir_with_two_absolute_dirs(self):
+        config = Config()
+        dirs = config._parse_migrations_dir('%s:%s:%s:%s' % (
+                os.path.abspath('test'), os.path.abspath('migrations'), 
+                os.path.abspath('./a/relative/path'), os.path.abspath('another/path'))
+        )
+        assert len(dirs) == 4
+        assert dirs[0] == os.path.abspath('test')
+        assert dirs[1] == os.path.abspath('migrations')
+        assert dirs[2] == os.path.abspath('./a/relative/path')
+        assert dirs[3] == os.path.abspath('another/path')
+
+class FileConfigTest(unittest.TestCase):
+
+    def setUp(self):
+        config_file = '''
+HOST = os.getenv('DB_HOST') or 'localhost'
+USERNAME = os.getenv('DB_USERNAME') or 'root'
+PASSWORD = os.getenv('DB_PASSWORD') or ''
+DATABASE = os.getenv('DB_DATABASE') or 'migration_example'
+MIGRATIONS_DIR = os.getenv('MIGRATIONS_DIR') or 'example'
+'''
+        f = open('sample.conf', 'w')
+        f.write(config_file)
+        f.close()
+
+    def tearDown(self):
+        os.remove('sample.conf')
+
+    def test_it_should_read_config_file(self):
+        config_path = os.path.abspath('sample.conf')
+        config = FileConfig(config_path)
+        self.assertEquals(config.get('db_host'), 'localhost')
+        self.assertEquals(config.get('db_user'), 'root')
+        self.assertEquals(config.get('db_password'), '')
+        self.assertEquals(config.get('db_name'), 'migration_example')
+        self.assertEquals(config.get('db_version_table'), Config.DB_VERSION_TABLE)
+        self.assertEquals(config.get('migrations_dir'), [os.path.abspath('example')])
+
+    def test_it_should_stop_execution_when_an_invalid_key_is_requested(self):
+        config_path = os.path.abspath('sample.conf')
+        config = FileConfig(config_path)
+        try:
+            config.get('invalid_config')
+            self.fail('it should not pass here')
+        except:
+            pass
+
+    def test_it_should_create_new_configs(self):
+        config_path = os.path.abspath('sample.conf')
+        config = FileConfig(config_path)
+
+        # ensure that the config does not exist
+        self.assertRaises(Exception, config.get, 'sample_config', 'TEST')
+
+        # create the config
+        config.put('sample_config', 'TEST')
+
+        # read the config
+        self.assertEquals(config.get('sample_config'), 'TEST')
+
+    def test_it_should_not_override_existing_configs(self):
+        config_path = os.path.abspath('sample.conf')
+        config = FileConfig(config_path)
+        config.put('sample_config', 'TEST')
+        self.assertRaises(Exception, config.put, 'sample_config', 'TEST')
+
+class InPlaceConfigTest(unittest.TestCase):
+
+    def test_it_should_configure_default_parameters(self):
+        config = InPlaceConfig('localhost', 'user', 'passwd', 'db', 'dir')
+        self.assertEquals(config.get('db_host'), 'localhost') 
+        self.assertEquals(config.get('db_user'), 'user')
+        self.assertEquals(config.get('db_password'), 'passwd')
+        self.assertEquals(config.get('db_name'), 'db')
+        self.assertEquals(config.get('db_version_table'), Config.DB_VERSION_TABLE)
+        self.assertEquals(config.get('migrations_dir'), [os.path.abspath('dir')])
+
+    def test_it_should_stop_execution_when_an_invalid_key_is_requested(self):
+        config = InPlaceConfig('localhost', 'user', 'passwd', 'db', 'dir')
+        try:
+            config.get('invalid_config')
+            self.fail('it should not pass here')
+        except:
+            pass
+
+    def test_it_should_create_new_configs(self):
+        config = InPlaceConfig('localhost', 'user', 'passwd', 'db', 'dir')
+
+        # ensure that the config does not exist
+        self.assertRaises(Exception, config.get, 'sample_config', 'TEST')
+
+        # create the config
+        config.put('sample_config', 'TEST')
+
+        # read the config
+        self.assertEquals(config.get('sample_config'), 'TEST')
+
+    def test_it_should_not_override_existing_configs(self):
+        config = InPlaceConfig('localhost', 'user', 'passwd', 'db', 'dir')
+        config.put('sample_config', 'TEST')
+        self.assertRaises(Exception, config.put, 'sample_config', 'TEST')
+
+if __name__ == '__main__':
+    unittest.main()