The compression spec has two sets of testing that is specified (of which we implement neither):

1:

In general, after implementing this functionality and the test cases, running the traditional client test suite against a server with compression enabled, and ensuring the test suite is configured to provide a valid compressor as part of the connection string, is a good idea. MongoDB-supported drivers MUST add such variant to their CI environment.

2:

The following cases assume a standalone MongoDB 3.4 (or later) node configured with:
mongod --networkMessageCompressors "snappy" -vvv
Connection strings, and results
<test cases>