NetworkController doesn't handle `eth_subscribe` or `eth_unsubscribe`
specially, but as it's supported by Infura, we want to make sure we
exercise these RPC methods in the network client tests, even if it is
just to ensure that they get passed through to the network.
We had tests for these RPC methods, but they were commented out in
c095b1accd when the network client code
was extracted to a separate file. At the time we were considering adding
subscription- and filter-based middleware to NetworkController, and so
we commented out the tests for `eth_subscribe` and `eth_unsubscribe`
temporarily until we could rewrite them in a way that would exercise the
new middleware. We reverted that change in
bd23a49013, which meant that we could
restore the existing tests, but it appears that this task was not caught
during review. This commit takes care of restoring them.
Co-authored-by: legobeat <109787230+legobeat@users.noreply.github.com>
05fb01802d