Zachary Tong 63fef5a31e Add scripting support to AggregatorTestCase (#43494)
This refactors AggregatorTestCase to allow testing mock scripts.
The main change is to QueryShardContext.  This was previously mocked,
but to get the ScriptService you have to invoke a final method
which can't be mocked.

Instead, we just create a mostly-empty QueryShardContext and populate
the fields that are needed for testing.  It also introduces a few
new helper methods that can be overridden to change the default
behavior a bit.

Most tests should be able to override getMockScriptService() to supply
a ScriptService to the context, which is later used by the aggs.
More complicated tests can override queryShardContextMock() as before.

Adds a test to MaxAggregatorTests to test out the new functionality.
2019-06-25 11:52:12 -04:00
..