consensus-test: include near-future headers in ChainSync client test

This now exercises the real ChainSync InFutureCheck.

Author: nfrisby

ouroboros-consensus/ouroboros-consensus.cabal

@@ -484,6 +484,7 @@ test-suite consensus-test
   build-depends:
     , async
     , base
+    , base-deriving-via
     , cardano-binary
     , cardano-crypto-class
     , cardano-slotting
@@ -505,6 +506,7 @@ test-suite consensus-test
     , ouroboros-network-protocols:{ouroboros-network-protocols, testlib}
     , QuickCheck
     , quickcheck-state-machine
+    , quiet
     , random
     , serialise
     , si-timers

ouroboros-consensus/src/ouroboros-consensus/Ouroboros/Consensus/Util/Time.hs

@@ -1,11 +1,22 @@
 module Ouroboros.Consensus.Util.Time (
-    -- Conversions
     nominalDelay
+  , multipleNominalDelay
   , secondsToNominalDiffTime
   ) where
 
 import           Data.Time (DiffTime, NominalDiffTime)
 
+{-------------------------------------------------------------------------------
+  Operations
+-------------------------------------------------------------------------------}
+
+-- | Multiply a 'NominalDiffTime' by an integer
+--
+-- The right conversions to use are somewhat tricky. The key fact is that
+-- 'fromIntegral' interprets its argument as seconds.
+multipleNominalDelay :: Integral a => NominalDiffTime -> a -> NominalDiffTime
+multipleNominalDelay dur i = dur * fromIntegral i
+
 {-------------------------------------------------------------------------------
   Conversions
 -------------------------------------------------------------------------------}