fixes

app/Main.hs

@@ -80,7 +80,7 @@ mineBlock stringData = do
 replaceChain :: MonadIO m => IORef [Block] -> [Block] -> m ()
 replaceChain chainRef newChain = do
   currentChain <- liftIO $ readIORef chainRef
-  if not $ isValidChain (Prelude.head currentChain) newChain || (length currentChain >= length newChain)
+  if not $ isValidChain newChain || (length currentChain >= length newChain)
     then liftDebug $ "chain is not valid for updating!: " ++ show newChain
     else do
       setChain <- liftIO $ atomicModifyIORef' chainRef $ const (newChain, newChain)
@@ -122,8 +122,7 @@ main = do
   _ <- initLogger $ p2pPort args
   debugM "legion" "starting"
   (localNode, procId) <- runP2P (p2pPort args) (seedNode args) (return ())
-  genesis <- initialBlock
-  ref <- maybe (newIORef [genesis]) (const $ newIORef []) (seedNode args)
+  ref <- maybe (newIORef [initialBlock]) (const $ newIORef []) (seedNode args)
   spockCfg <- defaultSpockCfg EmptySession PCNoDatabase (BlockChainState ref localNode procId)
   _ <- async $ runSpock (read (httpPort args) :: Int) (spock spockCfg Main.app)
   -- wait for messages to come in from the p2p network and respond to them

src/Lib.hs

@@ -46,11 +46,10 @@ addHashToBlock block = block { blockHash = calculateBlockHash block }
 -- a hardcoded initial block, we need this to make sure all
 -- nodes have the same starting point, so we have a hard coded
 -- frame of reference to detect validity
-initialBlock :: IO Block
+initialBlock :: Block
 initialBlock = do
-  time <- epoch
-  let block = Block 0 "0" time "initial data" ""
-  return $ block { blockHash = calculateBlockHash block }
+  let block = Block 0 "0" 0 "initial data" ""
+  block { blockHash = calculateBlockHash block }
 
 -- a new block is valid if its index is 1 higher, its
 -- previous hash points to our last block, and its hash is computed
@@ -64,13 +63,13 @@ isValidNewBlock prev next
 
 -- a chain is valid if it starts with our hardcoded initial
 -- block and every block is valid with respect to the previous
-isValidChain :: Block -> [Block] -> Bool
-isValidChain initial chain = case chain of
+isValidChain :: [Block] -> Bool
+isValidChain chain = case chain of
   [] -> True
-  [x] -> x == initial
+  [x] -> x == initialBlock
   (x:xs) ->
     let blockPairs = zip chain xs in
-      x == initial &&
+      x == initialBlock &&
       all (uncurry isValidNewBlock) blockPairs
 
 

test/Spec.hs

@@ -15,7 +15,7 @@ unitTests =
 testValidChain :: IO ()
 testValidChain  = do
   print "running test!"
-  b <- initialBlock
+  let b = initialBlock
   assertBool "block eq" $ b == b
   assertBool "empty chains are valid" $ isValidChain b []
   assertBool "base chain is valid" $ isValidChain b [b]