Add tests for llcp/err.py

tests/test_llcp_err.py

@@ -0,0 +1,23 @@
+# -*- coding: utf-8 -*-
+from __future__ import absolute_import, division
+
+import errno
+import nfc.llcp.err
+
+
+def test_llcp_error_class():
+    err = nfc.llcp.Error(errno.EPIPE)
+    assert isinstance(err, nfc.llcp.Error)
+    assert isinstance(err, IOError)
+    assert err.errno == errno.EPIPE
+    assert str(err) == "nfc.llcp.Error: [EPIPE] Broken pipe"
+
+
+def test_connect_refused():
+    err = nfc.llcp.ConnectRefused(reason=1)
+    assert isinstance(err, nfc.llcp.ConnectRefused)
+    assert isinstance(err, nfc.llcp.Error)
+    assert err.errno == errno.ECONNREFUSED
+    assert err.reason == 1
+    assert str(err) == ("nfc.llcp.ConnectRefused: [ECONNREFUSED] "
+                        "Connection refused with reason 1")