Add initial testing module for api.py

Author: timothycrosley

tests/test_api.py

@@ -0,0 +1,12 @@
+"""Tests the isort API module"""
+import pytest
+
+from isort import api, exceptions
+
+
+def test_sort_file_invalid_syntax(tmpdir) -> None:
+    """Test to ensure file encoding is respected"""
+    tmp_file = tmpdir.join(f"test_bad_syntax.py")
+    tmp_file.write_text("""print('mismathing quotes")""", "utf8")
+    with pytest.warns(UserWarning):
+        api.sort_file(tmp_file, atomic=True)