Fix exception name

bigchaindb/commands/bigchain.py

@@ -8,6 +8,7 @@ import argparse
 import bigchaindb
 import bigchaindb.config_utils
 from bigchaindb import db
+from bigchaindb.exceptions import DatabaseAlreadyExists
 from bigchaindb.commands.utils import base_parser, start
 from bigchaindb.processes import Processes
 from bigchaindb.crypto import generate_key_pair
@@ -75,7 +76,7 @@ def run_start(args):
     bigchaindb.config_utils.file_config(args.config)
     try:
         db.init()
-    except db.DatabaseAlreadyExistsException:
+    except DatabaseAlreadyExists:
         pass
     p = Processes()
     logger.info('Start bigchaindb main process')

tests/test_commands.py

@@ -0,0 +1,39 @@
+from argparse import Namespace
+
+import pytest
+
+
+@pytest.fixture
+def mock_run_configure(monkeypatch):
+    from bigchaindb.commands import bigchain
+    monkeypatch.setattr(bigchain, 'run_configure', lambda *args, **kwargs: None)
+
+
+@pytest.fixture
+def mock_file_config(monkeypatch):
+    from bigchaindb import config_utils
+    monkeypatch.setattr(config_utils, 'file_config', lambda *args: None)
+
+
+@pytest.fixture
+def mock_db_init_with_existing_db(monkeypatch):
+    from bigchaindb import db
+    from bigchaindb.exceptions import DatabaseAlreadyExists
+
+    def mockreturn():
+        raise DatabaseAlreadyExists
+
+    monkeypatch.setattr(db, 'init', mockreturn)
+
+
+@pytest.fixture
+def mock_processes_start(monkeypatch):
+    from bigchaindb.processes import Processes
+    monkeypatch.setattr(Processes, 'start', lambda *args: None)
+
+
+def test_bigchain_run_start(mock_run_configure, mock_file_config,
+                            mock_processes_start, mock_db_init_with_existing_db):
+    from bigchaindb.commands.bigchain import run_start
+    args = Namespace(config=None, yes=True)
+    run_start(args)