ghcide test IfaceTests, we should remove interface cache dir before we run the test, or the diganostic simply gone

[soulomoon]

This can happened in the second round doing the test.

Reproduce

Run this consectively

LSP_TEST_LOG_MESSAGES=1 LSP_TEST_LOG_STDERR=1  TASTY_PATTERN="iface-error-test-1" cabal test ghcide-tests

we are seeing

Debug | SUCCEEDED LOADING HIE FILE FOR /Users/ares/.cache/ghcide/main-67f5d3e80e9a5dab967334c225648bdcd080465f-67f5d3e80e9a5dab967334c225648bdcd080465f/P.hie

The test past again if we remove the cache dir entirely

[soulomoon]

A possible solution to this would be to remove the .cache dir in setupTestEnvironment, after we migrate this test to hls-test-utils.
But I need to see how much it is slowing down the test.

[komikat]

The test seems to time out on re-runs.

Exception: Timed out waiting to receive a message from the server.
Last message received:
{
    "jsonrpc": "2.0",
    "method": "$/progress",
    "params": {
        "token": "11",
        "value": {
            "kind": "end",
            "message": "Finished indexing 3 files"
        }
    }
}

[soulomoon]

@komikat Yes, since if we have the cache, we won't compile it again and hence the diganostic is not genereated

[komikat]

@soulomoon so expected behaviour should be to not wait for a diagnosis? or delete the specific component being cached before the test is run?

[soulomoon]

@komikat The point of the test is to assert wether the diganostic would arrive. So may be the latter.