tests: Add tests for defaults in core schema config

Tests check if default core schema has cache_dir, config_dir, data_dir and max_tracklist_length and if they have proper type

tests/config/test_defaults.py

@@ -0,0 +1,26 @@
+from __future__ import absolute_import, unicode_literals
+
+from mopidy import config
+
+
+def test_core_schema_has_cache_dir():
+    assert 'cache_dir' in config._core_schema
+    assert isinstance(config._core_schema['cache_dir'], config.Path)
+
+
+def test_core_schema_has_config_dir():
+    assert 'config_dir' in config._core_schema
+    assert isinstance(config._core_schema['config_dir'], config.Path)
+
+
+def test_core_schema_has_data_dir():
+    assert 'data_dir' in config._core_schema
+    assert isinstance(config._core_schema['data_dir'], config.Path)
+
+
+def test_core_schema_has_max_tracklist_length():
+    assert 'max_tracklist_length' in config._core_schema
+    max_tracklist_length_schema = config._core_schema['max_tracklist_length']
+    assert isinstance(max_tracklist_length_schema, config.Integer)
+    assert max_tracklist_length_schema._minimum == 1
+    assert max_tracklist_length_schema._maximum == 10000