resolver / add schema_resolver tests (wip)

Author: Nementon

tests/test_resolver/test_resolver_schema_resolver.py

@@ -0,0 +1,22 @@
+import urllib
+
+import pytest
+
+
+def test___init__invalid_data(mocker):
+    from openapi_python_client.resolver.schema_resolver import SchemaResolver
+
+    with pytest.raises(ValueError):
+        SchemaResolver(None)
+
+    invalid_url = "foobar"
+    with pytest.raises(ValueError):
+        SchemaResolver(invalid_url)
+
+    invalid_url = 42
+    with pytest.raises(urllib.error.URLError):
+        SchemaResolver(invalid_url)
+
+    invalid_url = mocker.Mock()
+    with pytest.raises(urllib.error.URLError):
+        SchemaResolver(invalid_url)