Improve tests and connection class

bigchaindb/backend/connection.py

@@ -61,7 +61,9 @@ def connect(backend=None, host=None, port=None, name=None, max_tries=None,
         raise ConfigurationError('Error loading backend `{}`'.format(backend)) from exc
 
     logger.debug('Connection: {}'.format(Class))
-    return Class(host=host, port=port, dbname=dbname, replicaset=replicaset)
+    return Class(host=host, port=port, dbname=dbname,
+                 max_tries=max_tries, connection_timeout=connection_timeout,
+                 replicaset=replicaset)
 
 
 class Connection:
@@ -142,3 +144,5 @@ class Connection:
                 if attempt == self.max_tries:
                     logger.critical('Cannot connect to the Database. Giving up.')
                     raise ConnectionError() from exc
+            else:
+                break

bigchaindb/backend/rethinkdb/changefeed.py

@@ -3,6 +3,7 @@ import logging
 import rethinkdb as r
 
 from bigchaindb import backend
+from bigchaindb.backend.exceptions import BackendError
 from bigchaindb.backend.changefeed import ChangeFeed
 from bigchaindb.backend.utils import module_dispatch_registrar
 from bigchaindb.backend.rethinkdb.connection import RethinkDBConnection
@@ -23,7 +24,7 @@ class RethinkDBChangeFeed(ChangeFeed):
             try:
                 self.run_changefeed()
                 break
-            except (r.ReqlDriverError, r.ReqlOpFailedError) as exc:
+            except BackendError as exc:
                 logger.exception(exc)
                 time.sleep(1)
 

bigchaindb/backend/rethinkdb/connection.py

@@ -1,7 +1,7 @@
 import rethinkdb as r
 
 from bigchaindb.backend.connection import Connection
-from bigchaindb.backend.exceptions import ConnectionError
+from bigchaindb.backend.exceptions import ConnectionError, OperationError
 
 
 class RethinkDBConnection(Connection):
@@ -24,7 +24,10 @@ class RethinkDBConnection(Connection):
                 :attr:`~.RethinkDBConnection.max_tries`.
         """
 
-        return query.run(self.conn)
+        try:
+            return query.run(self.conn)
+        except r.ReqlDriverError as exc:
+            raise OperationError from exc
 
     def _connect(self):
         """Set a connection to RethinkDB.
@@ -39,4 +42,4 @@ class RethinkDBConnection(Connection):
         try:
             return r.connect(host=self.host, port=self.port, db=self.dbname)
         except r.ReqlDriverError as exc:
-            raise ConnectionError() from exc
+            raise ConnectionError from exc

tests/backend/rethinkdb/test_connection.py

@@ -1,6 +1,7 @@
 import time
 import multiprocessing as mp
 from threading import Thread
+from unittest import mock
 from unittest.mock import patch
 
 import pytest
@@ -34,6 +35,7 @@ def test_run_a_simple_query():
 
 def test_raise_exception_when_max_tries():
     from bigchaindb.backend import connect
+    from bigchaindb.backend.exceptions import OperationError
 
     class MockQuery:
         def run(self, conn):
@@ -41,28 +43,41 @@ def test_raise_exception_when_max_tries():
 
     conn = connect()
 
-    with pytest.raises(r.ReqlDriverError):
+    with pytest.raises(OperationError):
         conn.run(MockQuery())
 
 
 def test_reconnect_when_connection_lost():
     from bigchaindb.backend import connect
 
-    def raise_exception(*args, **kwargs):
-        raise r.ReqlDriverError('mock')
-
-    conn = connect()
     original_connect = r.connect
-    r.connect = raise_exception
 
-    def delayed_start():
-        time.sleep(1)
-        r.connect = original_connect
+    with patch('rethinkdb.connect') as mock_connect:
+        mock_connect.side_effect = [
+            r.ReqlDriverError('mock'),
+            original_connect()
+        ]
 
-    thread = Thread(target=delayed_start)
-    query = r.expr('1')
-    thread.start()
-    assert conn.run(query) == '1'
+        conn = connect()
+        query = r.expr('1')
+        assert conn.run(query) == '1'
+
+
+def test_reconnect_when_connection_lost_tries_n_times():
+    from bigchaindb.backend import connect
+    from bigchaindb.backend.exceptions import ConnectionError
+
+    with patch('rethinkdb.connect') as mock_connect:
+        mock_connect.side_effect = [
+            r.ReqlDriverError('mock'),
+            r.ReqlDriverError('mock'),
+            r.ReqlDriverError('mock')
+        ]
+
+        conn = connect(max_tries=3)
+        query = r.expr('1')
+        with pytest.raises(ConnectionError):
+            assert conn.run(query) == '1'
 
 
 def test_changefeed_reconnects_when_connection_lost(monkeypatch):