Issue in yang files with mandatory leaf and mandatory statement in List container

In the scope of migrating functional tests from Honeynode to Lightynode simulator (derived from lighty.io Netconf simulator), we successfully migrated them for openroadm data models version 1.2.1 and 2.2.1 but we face some issues with functional tests using openroadm 7.1.0 models.

This issue would be related to yangtools which seems not to correctly manage “mandatory” leaf as well as the management of the “when” statement.

Since the openroadm yang models are quite complex, we summarize the following issues in a small yang model attached in the zip file, highlighted these two cases and report it in the ‘trace_MainBugWhenStatement.log’ file:

1/ When a container has a “leaf” set to “mandatory”, we can write this container into datastore even if this lead has not been set (not an issue so far for us).

2/ When a list container has a “leaf” with a “mandatory statement”, this leaf must always be set even if we have a when statement which is false (this is our issue).

This is typically the second case we encounter with functional test migration in TransportPCE and especially with org-openroadm-maintenance-testsignal@2020-0529.yang with the leaf ‘testPattern’ which is mandatory even if the when statement with the leaf ‘enabled’ is false.