api: add tests for EventGraceidField

gracedb/api/v1/events/tests/test_eventgraceidfield.py

+try:
+    from unittest import mock
+except ImportError:  # python < 3
+    import mock
+
+import pytest
+from rest_framework.exceptions import ValidationError
+
+from ..fields import EventGraceidField
+
+
+@pytest.mark.parametrize(
+    "graceid",
+    [1234, 1.234, (), [], None, True, lambda x: x]
+)
+def test_bad_types(graceid):
+    field = EventGraceidField()
+
+    err_msg = 'Event graceid must be a string.'
+    with pytest.raises(ValidationError, match=err_msg):
+        field.to_internal_value(graceid)
+
+
+@pytest.mark.parametrize(
+    "graceid",
+    ['GG', '1234G', 'G.1234', 'G1234z', 'Q1234', 'GH12']
+)
+def test_graceid_bad_format(graceid):
+    field = EventGraceidField()
+
+    err_msg = 'Not a valid graceid.'
+    with pytest.raises(ValidationError, match=err_msg):
+        field.to_internal_value(graceid)
+
+
+@pytest.mark.parametrize(
+    "graceid",
+    ['G1234', 'E0001', 'H12', 'M352345', 'T2323', ' T123', 'T123 ', ' T123 ',
+     'g4567', 't456 ', ' m2398     ', '  e8732']
+)
+def test_valid_graceids(graceid):
+    field = EventGraceidField()
+
+    # WHY do we have to mock this as 'gracedb.api...'
+    # instead of just 'api...'??
+    super_tiv = 'gracedb.api.v1.fields.GenericField.to_internal_value'
+    with mock.patch(super_tiv) as mock_super_tiv:
+        field.to_internal_value(graceid)
+
+    call_args, _ = mock_super_tiv.call_args
+    assert mock_super_tiv.call_count == 1
+    assert len(call_args) == 1
+    assert call_args[0].encode() == graceid.upper().strip()