tests: Add tests for decoding actual pack file

test/unit/Cardano/Wallet/PackfileSpec.hs

@@ -4,12 +4,19 @@ module Cardano.Wallet.PackfileSpec (spec) where
 
 import Prelude
 
+import qualified Data.ByteString.Char8 as B8
 import qualified Data.ByteString.Lazy.Char8 as L8
 
+import Data.Either
+    ( fromRight, isRight )
 import Test.Hspec
-    ( Spec, describe, it, shouldBe )
+    ( Spec, describe, it, shouldBe, shouldSatisfy )
 
+import Cardano.Wallet.Primitive (Block(..), BlockHeader(..))
 import Cardano.Wallet.Binary.Packfile
+    (decodePackfile, PackfileError (..))
+import Cardano.Wallet.Binary (decodeBlock)
+import Cardano.Wallet.BinaryHelpers (unsafeDeserialiseFromBytes)
 
 -- version 1 header
 packFileHeader :: L8.ByteString
@@ -23,6 +30,11 @@ testTwoBlobs = packFileHeader
         <> "\0\0\0\11first block\0"
         <> "\0\0\0\12second block"
 
+-- Get this file from cardano-http-bridge with:
+-- wget -O test/data/epoch-mainnet-104 http://localhost:8080/mainnet/epoch/104
+testPackfile :: FilePath
+testPackfile = "test/data/epoch-mainnet-104"
+
 spec :: Spec
 spec = do
     describe "Decoding pack file" $ do
@@ -56,3 +68,33 @@ spec = do
         it "should reject extra data" $ do
             let decoded = decodePackfile (packFileHeader <> "a")
             decoded `shouldBe` Left (BlobDecodeError "not enough bytes")
+
+    describe "Decoding a mainnet pack file" $ do
+        it "should decode pack file for mainnet epoch 104" $ do
+            bs <- L8.readFile testPackfile
+            let decoded = decodePackfile bs
+            decoded `shouldSatisfy` isRight
+            length (fromRight [] decoded) `shouldBe` 21600
+
+        it "should decode the entire blocks" $ do
+            bs <- L8.readFile testPackfile
+            let Right (first:second:_) = decodePackfile bs
+            B8.length first `shouldBe` 648092
+            B8.length second `shouldBe` 1181
+
+        it "should decode correct blocks" $ do
+            bs <- L8.readFile testPackfile
+            let (ebb:first:second:_) = map header $ unsafeDeserialiseEpoch bs
+            epochIndex ebb `shouldBe` 104
+            epochIndex first `shouldBe` 104
+            slotNumber ebb `shouldBe` 0 -- epoch genesis block
+            slotNumber first `shouldBe` 0 -- first block
+            slotNumber second `shouldBe` 1 -- second block
+
+-- | Decode all blocks in a pack file, without error handling
+unsafeDeserialiseEpoch :: L8.ByteString -> [Block]
+unsafeDeserialiseEpoch = either giveUp decodeBlocks . decodePackfile
+    where
+        decodeBlocks = map decodeBlob
+        decodeBlob = unsafeDeserialiseFromBytes decodeBlock . L8.fromStrict
+        giveUp err = error ("Could not decode pack file: " <> show err)