Add test to verify that put_metric sets non-given values to None (rep…

…laces the instance).

tests/test_routes.py

@@ -174,6 +174,29 @@ def test_api_put_metric(client, populated_db):
     assert d['new_value']['units'] == "lines"
 
 
+def test_api_put_metric_sets_other_values_to_none(client, populated_db):
+    name = "with_everything"
+
+    original = client.get("/api/v1/metric/{}".format(name))
+    assert original.status_code == 200
+    original = original.get_json()
+    assert original['units'] == 'percent'
+    assert original['upper_limit'] == 100.0
+    assert original['lower_limit'] == 20.0
+
+    data = {"name": name}
+    rv = client.put("/api/v1/metric/{}".format(name), json=data)
+    assert rv.status_code == 200
+
+    new = client.get("/api/v1/metric/{}".format(name))
+    assert new.status_code == 200
+    new = new.get_json()
+
+    assert new['units'] is None
+    assert new['upper_limit'] is None
+    assert new['lower_limit'] is None
+
+
 def test_api_put_metric_not_found(client, populated_db):
     name = "missing"
     data = {