Currently we have a huge test (jstests/aggregation/testshard1.js) that tests many different things, and we would like to split it into multiple files. However, tests in this file all rely on some setup code that inserts a bunch of data into a sharded collection. This takes a while, and we would significantly slow down the tests if we split them up by functionality.

We should add some logic, probably to resmoke.py, to set up a fixture with some data already loaded. For example, we could specify in the suite's YAML what collections to create, how to shard them, and what data to insert. This way, we could have a bunch of different test files that share a common setup, and can avoid large tests that obscure what they are testing.