#35: Checking if a file is empty or does not define SQL_UP or SQL_DOWN.

src/simple_db_migrate/core.py

@@ -29,14 +29,26 @@ def get_all_migration_files(self):
         return files
 
     def get_sql_command(self, sql_file, migration_up=True):
-        f = open(self.__migrations_dir + "/" + sql_file, "r")
-        exec(f.read())
-        f.close()
-
-        if migration_up:
-            return SQL_UP
+        try:
+            f = open(self.__migrations_dir + "/" + sql_file, "r")
+            exec(f.read())
+        except IOError:
+            self.__cli.error_and_exit("%s: file not found" % self.__migrations_dir + "/" + sql_file)
         else:
-            return SQL_DOWN
+            f.close()
+
+        try:
+            (SQL_UP, SQL_DOWN)
+        except NameError:
+            self.__cli.error_and_exit("migration file is incorrect; it does not define 'SQL_UP' or 'SQL_DOWN' ('%s')" % sql_file)
+
+        sql = ""
+        sql = SQL_UP if migration_up else SQL_DOWN
+
+        if sql is None or sql == "":
+            self.__cli.error_and_exit("migration command is empty ('%s')" % sql_file)
+
+        return sql    
 
     def get_all_migration_versions(self):
         versions = []

tests/core_test.py

@@ -30,6 +30,14 @@ def setUp(self):
         f.close()
         self.__test_migration_files.append(file_with_commands)
 
+        # migration file without commands
+        file_without_commands = "20090214120700_example_migration_file_without_commands.migration"
+        f = open(file_without_commands, "w")
+        f.write("SQL_UP = ''\n")
+        f.write("SQL_DOWN = ''\n")
+        f.close()
+        self.__test_migration_files.append(file_without_commands)
+
         # very very last schema version available
         file_in_the_future = "21420101000000_example_migration_file.migration"
         self.__create_empty_file(file_in_the_future)
@@ -106,6 +114,26 @@ def test_it_should_get_migration_down_command_in_file(self):
         sql = db_migrate.get_sql_command(migration_file, False)
         self.assertEquals(sql, "drop table test;")
 
+    def test_it_should_not_get_migration_command_in_files_with_blank_commands(self):
+        db_migrate = SimpleDBMigrate(".")
+        migration_file = "20090214120700_example_migration_file_without_commands.migration"
+        try:
+            sql = db_migrate.get_sql_command(migration_file, True)
+            self.fail("it should not pass here")
+        except:
+            pass
+
+    def test_it_should_not_get_migration_command_in_empty_file(self):
+        db_migrate = SimpleDBMigrate(".")
+        migration_file = self.__test_migration_files[0]
+        try:
+            sql = db_migrate.get_sql_command(migration_file, True)
+            self.fail("it should not pass here")
+        except NameError:
+            self.fail("it should not pass here")
+        except:
+            pass
+
     def test_it_should_get_migration_version_from_file(self):
         db_migrate = SimpleDBMigrate(".")
         # good file name