diff --git a/app/Main.hs b/app/Main.hs
index bca9a0b0b..1d1931b29 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -23,6 +23,7 @@ import MiniJuvix.Syntax.Concrete.Scoped.Pretty.Base qualified as M
 import MiniJuvix.Syntax.Concrete.Scoped.Pretty.Html
 import MiniJuvix.Syntax.Concrete.Scoped.Pretty.Text qualified as T
 import MiniJuvix.Syntax.Concrete.Scoped.Scoper qualified as Scoper
+import MiniJuvix.Syntax.MicroJuvix.Error qualified as Micro
 import MiniJuvix.Syntax.MicroJuvix.Language qualified as Micro
 import MiniJuvix.Syntax.MicroJuvix.Pretty.Ansi qualified as Micro
 import MiniJuvix.Syntax.MicroJuvix.TypeChecker qualified as Micro
@@ -350,7 +351,7 @@ runCommand c = do
       micro <- miniToMicro root o
       case Micro.checkModule micro of
         Right _ -> putStrLn "Well done! It type checks"
-        Left es -> sequence_ (intersperse (putStrLn "") (printErrorAnsi <$> toList es)) >> exitFailure
+        Left (Micro.TypeCheckerErrors es) -> sequence_ (intersperse (putStrLn "") (printErrorAnsi <$> toList es)) >> exitFailure
     MiniHaskell o -> do
       a <- head . (^. Abstract.resultModules) <$> runIO (upToAbstract (getEntryPoint root o))
       let micro = Micro.translateModule a
@@ -358,7 +359,7 @@ runCommand c = do
         Right checkedMicro -> do
           minihaskell <- fromRightIO' putStrLn (return $ Hask.translateModule checkedMicro)
           Hask.printPrettyCodeDefault minihaskell
-        Left es -> mapM_ printErrorAnsi es >> exitFailure
+        Left es -> printErrorAnsi es >> exitFailure
     Termination (Calls opts@CallsOptions {..}) -> do
       a <- head . (^. Abstract.resultModules) <$> runIO (upToAbstract (getEntryPoint root opts))
       let callMap0 = T.buildCallMap a
diff --git a/src/MiniJuvix/Pipeline.hs b/src/MiniJuvix/Pipeline.hs
index ab1afbbb4..168879dc8 100644
--- a/src/MiniJuvix/Pipeline.hs
+++ b/src/MiniJuvix/Pipeline.hs
@@ -14,6 +14,7 @@ import MiniJuvix.Syntax.Abstract.AbstractResult qualified as Abstract
 import MiniJuvix.Syntax.Concrete.Parser qualified as Parser
 import MiniJuvix.Syntax.Concrete.Scoped.Scoper qualified as Scoper
 import MiniJuvix.Syntax.MicroJuvix.MicroJuvixResult qualified as MicroJuvix
+import MiniJuvix.Syntax.MicroJuvix.MicroJuvixTypedResult qualified as MicroJuvix
 import MiniJuvix.Translation.AbstractToMicroJuvix qualified as MicroJuvix
 import MiniJuvix.Translation.ScopedToAbstract qualified as Abstract
 
@@ -31,8 +32,13 @@ type family StageResult c = res | res -> c where
   StageResult 'Scoping = Scoper.ScoperResult
   StageResult 'Abstract = Abstract.AbstractResult
 
+--------------------------------------------------------------------------------
+
+runIOEither :: Sem '[Files, Error AJuvixError, Embed IO] a -> IO (Either AJuvixError a)
+runIOEither = runM . runError . runFilesIO
+
 runIO :: Sem '[Files, Error AJuvixError, Embed IO] a -> IO a
-runIO = (runM . runError . runFilesIO) >=> mayThrow
+runIO = runIOEither >=> mayThrow
   where
     mayThrow :: Either AJuvixError r -> IO r
     mayThrow = \case
@@ -53,8 +59,8 @@ upToAbstract = upToScoping >=> pipelineAbstract
 upToMicroJuvix :: Members '[Files, Error AJuvixError] r => EntryPoint -> Sem r MicroJuvix.MicroJuvixResult
 upToMicroJuvix = upToAbstract >=> pipelineMicroJuvix
 
--- upToMicroJuvixTyped :: Members '[Files, Error AJuvixError] r => EntryPoint -> Sem r MicroJuvixTyped.MicroJuvixTypedResult
--- upToMicroJuvixTyped = upToMicroJuvix >=> pipelineMicroJuvixTyped
+upToMicroJuvixTyped :: Members '[Files, Error AJuvixError] r => EntryPoint -> Sem r MicroJuvix.MicroJuvixTypedResult
+upToMicroJuvixTyped = upToMicroJuvix >=> pipelineMicroJuvixTyped
 
 --------------------------------------------------------------------------------
 
@@ -76,8 +82,9 @@ pipelineMicroJuvix ::
   Sem r MicroJuvix.MicroJuvixResult
 pipelineMicroJuvix = mapError (toAJuvixError @Text) . MicroJuvix.entryMicroJuvix
 
--- pipelineMicroJuvixTyped ::
---   Members '[Files, Error AJuvixError] r =>
---   Abstract.AbstractResult ->
---   Sem r MicroJuvix.MicroJuvixResult
--- pipelineMicroJuvixTyped = mapError (toAJuvixError @Text) . MicroJuvix.entryMicroJuvixTyped
+-- TODO:
+pipelineMicroJuvixTyped ::
+  Members '[Files, Error AJuvixError] r =>
+  MicroJuvix.MicroJuvixResult ->
+  Sem r MicroJuvix.MicroJuvixTypedResult
+pipelineMicroJuvixTyped = undefined
diff --git a/src/MiniJuvix/Pipeline/EntryPoint.hs b/src/MiniJuvix/Pipeline/EntryPoint.hs
index 8ab818882..b431c5a85 100644
--- a/src/MiniJuvix/Pipeline/EntryPoint.hs
+++ b/src/MiniJuvix/Pipeline/EntryPoint.hs
@@ -6,5 +6,6 @@ data EntryPoint = EntryPoint
   { _entryRoot :: FilePath,
     _entryModulePaths :: NonEmpty FilePath
   }
+  deriving stock (Eq, Show)
 
 makeLenses ''EntryPoint
diff --git a/src/MiniJuvix/Prelude/Error.hs b/src/MiniJuvix/Prelude/Error.hs
index 7560ddbbe..dec04abac 100644
--- a/src/MiniJuvix/Prelude/Error.hs
+++ b/src/MiniJuvix/Prelude/Error.hs
@@ -33,6 +33,15 @@ fromAJuvixError (AJuvixError e) = cast e
 throwJuvixError :: (JuvixError err, Member (Error AJuvixError) r) => err -> Sem r a
 throwJuvixError = throw . toAJuvixError
 
+runErrorIO ::
+  (JuvixError a, Member (Embed IO) r) =>
+  Sem (Error a ': r) b ->
+  Sem r b
+runErrorIO =
+  runError >=> \case
+    Left err -> embed (printErrorAnsi err >> exitFailure)
+    Right a -> return a
+
 instance JuvixError Text where
   renderText = id
 
diff --git a/src/MiniJuvix/Syntax/Abstract/Language.hs b/src/MiniJuvix/Syntax/Abstract/Language.hs
index 8531325e3..d007f4db0 100644
--- a/src/MiniJuvix/Syntax/Abstract/Language.hs
+++ b/src/MiniJuvix/Syntax/Abstract/Language.hs
@@ -38,12 +38,12 @@ data Module s = Module
   { _moduleName :: S.Name' s,
     _moduleBody :: ModuleBody
   }
-  deriving stock (Show, Eq)
+  deriving stock (Eq, Show)
 
 newtype ModuleBody = ModuleBody
   { _moduleStatements :: [Statement]
   }
-  deriving stock (Show, Eq)
+  deriving stock (Eq, Show)
 
 data Statement
   = StatementInductive InductiveDef
@@ -52,39 +52,39 @@ data Statement
   | StatementForeign ForeignBlock
   | StatementLocalModule LocalModule
   | StatementAxiom AxiomDef
-  deriving stock (Show, Eq)
+  deriving stock (Eq, Show)
 
 data FunctionDef = FunctionDef
   { _funDefName :: FunctionName,
     _funDefTypeSig :: Expression,
     _funDefClauses :: NonEmpty FunctionClause
   }
-  deriving stock (Show, Eq)
+  deriving stock (Eq, Show)
 
 data FunctionClause = FunctionClause
   { _clausePatterns :: [Pattern],
     _clauseBody :: Expression
   }
-  deriving stock (Show, Eq)
+  deriving stock (Eq, Show)
 
 newtype FunctionRef = FunctionRef
   {_functionRefName :: Name}
-  deriving stock (Show, Eq)
+  deriving stock (Eq, Show)
   deriving newtype (Hashable)
 
 newtype ConstructorRef = ConstructorRef
   {_constructorRefName :: Name}
-  deriving stock (Show, Eq)
+  deriving stock (Eq, Show)
   deriving newtype (Hashable)
 
 newtype InductiveRef = InductiveRef
   {_inductiveRefName :: Name}
-  deriving stock (Show, Eq)
+  deriving stock (Eq, Show)
   deriving newtype (Hashable)
 
 newtype AxiomRef = AxiomRef
   {_axiomRefName :: Name}
-  deriving stock (Show, Eq)
+  deriving stock (Eq, Show)
   deriving newtype (Hashable)
 
 data Iden
@@ -93,7 +93,7 @@ data Iden
   | IdenVar VarName
   | IdenInductive InductiveRef
   | IdenAxiom AxiomRef
-  deriving stock (Show, Eq)
+  deriving stock (Eq, Show)
 
 data Expression
   = ExpressionIden Iden
@@ -103,7 +103,7 @@ data Expression
   | ExpressionLiteral LiteralLoc
   --- | ExpressionMatch Match
   ---  ExpressionLambda Lambda not supported yet
-  deriving stock (Show, Eq)
+  deriving stock (Eq, Show)
 
 instance HasAtomicity Expression where
   atomicity e = case e of
@@ -117,45 +117,45 @@ data Match = Match
   { _matchExpression :: Expression,
     _matchAlts :: [MatchAlt]
   }
-  deriving stock (Show, Eq)
+  deriving stock (Eq, Show)
 
 data MatchAlt = MatchAlt
   { _matchAltPattern :: Pattern,
     _matchAltBody :: Expression
   }
-  deriving stock (Show, Eq)
+  deriving stock (Eq, Show)
 
 data Application = Application
   { _appLeft :: Expression,
     _appRight :: Expression
   }
-  deriving stock (Show, Eq)
+  deriving stock (Eq, Show)
 
 instance HasAtomicity Application where
   atomicity = const (Aggregate appFixity)
 
 newtype Lambda = Lambda
   {_lambdaClauses :: [LambdaClause]}
-  deriving stock (Show, Eq)
+  deriving stock (Eq, Show)
 
 data LambdaClause = LambdaClause
   { _lambdaParameters :: NonEmpty Pattern,
     _lambdaBody :: Expression
   }
-  deriving stock (Show, Eq)
+  deriving stock (Eq, Show)
 
 data FunctionParameter = FunctionParameter
   { _paramName :: Maybe VarName,
     _paramUsage :: Usage,
     _paramType :: Expression
   }
-  deriving stock (Show, Eq)
+  deriving stock (Eq, Show)
 
 data Function = Function
   { _funParameter :: FunctionParameter,
     _funReturn :: Expression
   }
-  deriving stock (Show, Eq)
+  deriving stock (Eq, Show)
 
 instance HasAtomicity Function where
   atomicity = const (Aggregate funFixity)
@@ -165,14 +165,14 @@ data ConstructorApp = ConstructorApp
   { _constrAppConstructor :: ConstructorRef,
     _constrAppParameters :: [Pattern]
   }
-  deriving stock (Show, Eq)
+  deriving stock (Eq, Show)
 
 data Pattern
   = PatternVariable VarName
   | PatternConstructorApp ConstructorApp
   | PatternWildcard
   | PatternEmpty
-  deriving stock (Show, Eq)
+  deriving stock (Eq, Show)
 
 data InductiveDef = InductiveDef
   { _inductiveName :: InductiveName,
@@ -180,20 +180,20 @@ data InductiveDef = InductiveDef
     _inductiveType :: Maybe Expression,
     _inductiveConstructors :: [InductiveConstructorDef]
   }
-  deriving stock (Show, Eq)
+  deriving stock (Eq, Show)
 
 data InductiveConstructorDef = InductiveConstructorDef
   { _constructorName :: ConstrName,
     _constructorType :: Expression
   }
-  deriving stock (Show, Eq)
+  deriving stock (Eq, Show)
 
 data AxiomDef = AxiomDef
   { _axiomName :: AxiomName,
     _axiomType :: Expression,
     _axiomBackendItems :: [BackendItem]
   }
-  deriving stock (Show, Eq)
+  deriving stock (Eq, Show)
 
 makeLenses ''Module
 makeLenses ''FunctionParameter
diff --git a/src/MiniJuvix/Syntax/Concrete/Language/Stage.hs b/src/MiniJuvix/Syntax/Concrete/Language/Stage.hs
index 3ad649e41..98c3cbb04 100644
--- a/src/MiniJuvix/Syntax/Concrete/Language/Stage.hs
+++ b/src/MiniJuvix/Syntax/Concrete/Language/Stage.hs
@@ -7,6 +7,6 @@ import MiniJuvix.Prelude
 data Stage
   = Parsed
   | Scoped
-  deriving stock (Show)
+  deriving stock (Eq, Show)
 
 $(genSingletons [''Stage])
diff --git a/src/MiniJuvix/Syntax/Concrete/Parser/InfoTable.hs b/src/MiniJuvix/Syntax/Concrete/Parser/InfoTable.hs
index 1058291a6..8b39a2f1a 100644
--- a/src/MiniJuvix/Syntax/Concrete/Parser/InfoTable.hs
+++ b/src/MiniJuvix/Syntax/Concrete/Parser/InfoTable.hs
@@ -7,5 +7,6 @@ newtype InfoTable = InfoTable
   { _infoParsedItems :: [ParsedItem]
   }
   deriving newtype (Semigroup, Monoid)
+  deriving stock (Eq, Show)
 
 makeLenses ''InfoTable
diff --git a/src/MiniJuvix/Syntax/Concrete/Parser/ParserResult.hs b/src/MiniJuvix/Syntax/Concrete/Parser/ParserResult.hs
index f8fdd4ccc..663c9bb8a 100644
--- a/src/MiniJuvix/Syntax/Concrete/Parser/ParserResult.hs
+++ b/src/MiniJuvix/Syntax/Concrete/Parser/ParserResult.hs
@@ -10,5 +10,6 @@ data ParserResult = ParserResult
     _resultTable :: InfoTable,
     _resultModules :: NonEmpty (Module 'Parsed 'ModuleTop)
   }
+  deriving stock (Eq, Show)
 
 makeLenses ''ParserResult
diff --git a/src/MiniJuvix/Syntax/Concrete/Scoped/InfoTable.hs b/src/MiniJuvix/Syntax/Concrete/Scoped/InfoTable.hs
index f298812cb..3efb99ce3 100644
--- a/src/MiniJuvix/Syntax/Concrete/Scoped/InfoTable.hs
+++ b/src/MiniJuvix/Syntax/Concrete/Scoped/InfoTable.hs
@@ -7,19 +7,23 @@ import MiniJuvix.Syntax.Concrete.Scoped.Name qualified as S
 newtype FunctionInfo = FunctionInfo
   { _functionInfoType :: Expression
   }
+  deriving stock (Eq, Show)
 
 newtype ConstructorInfo = ConstructorInfo
   { _constructorInfoType :: Expression
   }
+  deriving stock (Eq, Show)
 
 data AxiomInfo = AxiomInfo
   { _axiomInfoType :: Expression,
     _axiomInfoBackends :: [BackendItem]
   }
+  deriving stock (Eq, Show)
 
 newtype InductiveInfo = InductiveInfo
   { _inductiveInfoDef :: InductiveDef 'Scoped
   }
+  deriving stock (Eq, Show)
 
 data InfoTable = InfoTable
   { _infoConstructors :: HashMap ConstructorRef ConstructorInfo,
@@ -29,6 +33,7 @@ data InfoTable = InfoTable
     _infoFunctionClauses :: HashMap S.Symbol (FunctionClause 'Scoped),
     _infoNames :: [S.Name]
   }
+  deriving stock (Eq, Show)
 
 emptyInfoTable :: InfoTable
 emptyInfoTable =
diff --git a/src/MiniJuvix/Syntax/Concrete/Scoped/Scoper/ScoperResult.hs b/src/MiniJuvix/Syntax/Concrete/Scoped/Scoper/ScoperResult.hs
index 8c3465eb0..8a037c14c 100644
--- a/src/MiniJuvix/Syntax/Concrete/Scoped/Scoper/ScoperResult.hs
+++ b/src/MiniJuvix/Syntax/Concrete/Scoped/Scoper/ScoperResult.hs
@@ -11,5 +11,6 @@ data ScoperResult = ScoperResult
     _resultScoperTable :: Scoped.InfoTable,
     _resultModules :: NonEmpty (Module 'Scoped 'ModuleTop)
   }
+  deriving stock (Eq, Show)
 
 makeLenses ''ScoperResult
diff --git a/src/MiniJuvix/Syntax/Concrete/Scoped/Utils.hs b/src/MiniJuvix/Syntax/Concrete/Scoped/Utils.hs
index 3a8e4874e..14405ae05 100644
--- a/src/MiniJuvix/Syntax/Concrete/Scoped/Utils.hs
+++ b/src/MiniJuvix/Syntax/Concrete/Scoped/Utils.hs
@@ -18,6 +18,7 @@ getAllModules m =
     allImports (MkScopedModule _ w) =
       concat [i : allImports (mkScopedModule t) | StatementImport i@(Import t) <- _moduleBody w]
         <> concatMap (allImports . mkScopedModule) [l | StatementModule l <- _moduleBody w]
+
     singl :: Module 'Scoped 'ModuleTop -> (S.NameId, Module 'Scoped 'ModuleTop)
     singl n = (S._nameId (_modulePath n), n)
 
diff --git a/src/MiniJuvix/Syntax/MicroJuvix/Error.hs b/src/MiniJuvix/Syntax/MicroJuvix/Error.hs
index d9cc30b8a..a187505f6 100644
--- a/src/MiniJuvix/Syntax/MicroJuvix/Error.hs
+++ b/src/MiniJuvix/Syntax/MicroJuvix/Error.hs
@@ -5,12 +5,18 @@ module MiniJuvix.Syntax.MicroJuvix.Error
   )
 where
 
-import MiniJuvix.Prelude
+--------------------------------------------------------------------------------
+
+import Data.Text qualified as Text
+import MiniJuvix.Prelude qualified as Prelude
+import MiniJuvix.Prelude.Base
 import MiniJuvix.Syntax.MicroJuvix.Error.Pretty
 import MiniJuvix.Syntax.MicroJuvix.Error.Pretty qualified as P
 import MiniJuvix.Syntax.MicroJuvix.Error.Types
 import Prettyprinter
 
+--------------------------------------------------------------------------------
+
 data TypeCheckerError
   = ErrTooManyPatterns TooManyPatterns
   | ErrWrongConstructorType WrongConstructorType
@@ -19,6 +25,13 @@ data TypeCheckerError
   | ErrExpectedFunctionType ExpectedFunctionType
   deriving stock (Show)
 
+newtype TypeCheckerErrors = TypeCheckerErrors
+  { _unTypeCheckerErrors :: NonEmpty TypeCheckerError
+  }
+  deriving stock (Show)
+
+makeLenses ''TypeCheckerErrors
+
 ppTypeCheckerError :: TypeCheckerError -> Doc Eann
 ppTypeCheckerError = \case
   ErrWrongConstructorType e -> ppError e
@@ -30,9 +43,16 @@ ppTypeCheckerError = \case
 docStream :: TypeCheckerError -> SimpleDocStream Eann
 docStream = layoutPretty defaultLayoutOptions . ppTypeCheckerError
 
-instance JuvixError TypeCheckerError where
+instance Prelude.JuvixError TypeCheckerError where
   renderAnsiText :: TypeCheckerError -> Text
   renderAnsiText = renderAnsi . docStream
 
   renderText :: TypeCheckerError -> Text
   renderText = P.renderText . docStream
+
+instance Prelude.JuvixError TypeCheckerErrors where
+  renderAnsiText :: TypeCheckerErrors -> Text
+  renderAnsiText TypeCheckerErrors {..} = (Text.unlines . toList) (fmap Prelude.renderAnsiText _unTypeCheckerErrors)
+
+  renderText :: TypeCheckerErrors -> Text
+  renderText TypeCheckerErrors {..} = (Text.unlines . toList) (fmap Prelude.renderText _unTypeCheckerErrors)
diff --git a/src/MiniJuvix/Syntax/MicroJuvix/TypeChecker.hs b/src/MiniJuvix/Syntax/MicroJuvix/TypeChecker.hs
index e00851b0f..42b94af5f 100644
--- a/src/MiniJuvix/Syntax/MicroJuvix/TypeChecker.hs
+++ b/src/MiniJuvix/Syntax/MicroJuvix/TypeChecker.hs
@@ -14,12 +14,12 @@ newtype LocalVars = LocalVars
 
 makeLenses ''LocalVars
 
-checkModule :: Module -> Either (NonEmpty TypeCheckerError) Module
+checkModule :: Module -> Either TypeCheckerErrors Module
 checkModule m = run $ do
   (es, checkedModule) <- runOutputList $ runReader (buildTable m) (checkModule' m)
-  return $ case es of
-    [] -> Right checkedModule
-    (x : xs) -> Left (x :| xs)
+  return $ case nonEmpty es of
+    Nothing -> Right checkedModule
+    Just xs -> Left (TypeCheckerErrors {_unTypeCheckerErrors = xs})
 
 checkModule' ::
   Members '[Reader InfoTable, Output TypeCheckerError] r =>
diff --git a/test/Base.hs b/test/Base.hs
index c8faa7593..f44470398 100644
--- a/test/Base.hs
+++ b/test/Base.hs
@@ -7,38 +7,35 @@ module Base
 where
 
 import MiniJuvix.Prelude
-import MiniJuvix.Syntax.Abstract.Language qualified as A
-import MiniJuvix.Syntax.Concrete.Language qualified as M
-import MiniJuvix.Syntax.Concrete.Parser qualified as M
-import MiniJuvix.Syntax.Concrete.Scoped.Scoper qualified as M
-import MiniJuvix.Translation.ScopedToAbstract qualified as A
 import Test.Tasty
 import Test.Tasty.HUnit
 
-parseModuleIO :: FilePath -> IO (M.Module 'M.Parsed 'M.ModuleTop)
-parseModuleIO = fromRightIO id . Parser.runModuleParserIO
+-- parseModuleIO :: FilePath -> IO (M.Module 'M.Parsed 'M.ModuleTop)
+-- parseModuleIO = fromRightIO id . Parser.runModuleParserIO
 
-parseTextModuleIO :: Text -> IO (M.Module 'M.Parsed 'M.ModuleTop)
-parseTextModuleIO = fromRightIO id . return . Parser.runModuleParser "literal string"
+-- parseTextModuleIO :: Text -> IO (M.Module 'M.Parsed 'M.ModuleTop)
+-- parseTextModuleIO = fromRightIO id . return . Parser.runModuleParser "literal string"
 
-scopeModuleIO :: M.Module 'M.Parsed 'M.ModuleTop -> IO (M.Module 'M.Scoped 'M.ModuleTop)
-scopeModuleIO = fmap (head . Scoper._resultModules) . fromRightIO' printErrorAnsi . Scoper.scopeCheck1IO "."
+-- scopeModuleIO :: M.Module 'M.Parsed 'M.ModuleTop -> IO (M.Module 'M.Scoped 'M.ModuleTop)
+-- scopeModuleIO = fmap (head . Scoper._resultModules) . fromRightIO' printErrorAnsi . Scoper.scopeCheck1IO "."
 
-translateModuleIO :: M.Module 'M.Scoped 'M.ModuleTop -> IO A.TopModule
-translateModuleIO = fmap snd . fromRightIO id . return . A.translateModule
+-- translateModuleIO :: M.Module 'M.Scoped 'M.ModuleTop -> IO A.TopModule
+-- translateModuleIO = fmap snd . fromRightIO id . return . A.translateModule
 
 data AssertionDescr
   = Single Assertion
   | Steps ((String -> IO ()) -> Assertion)
 
 data TestDescr = TestDescr
-  { testName :: String,
-    testRoot :: FilePath,
+  { _testName :: String,
+    _testRoot :: FilePath,
     -- | relative to root
-    testAssertion :: AssertionDescr
+    _testAssertion :: AssertionDescr
   }
 
+makeLenses ''TestDescr
+
 mkTest :: TestDescr -> TestTree
-mkTest TestDescr {..} = case testAssertion of
-  Single assertion -> testCase testName $ withCurrentDirectory testRoot assertion
-  Steps steps -> testCaseSteps testName (withCurrentDirectory testRoot . steps)
+mkTest TestDescr {..} = case _testAssertion of
+  Single assertion -> testCase _testName $ withCurrentDirectory _testRoot assertion
+  Steps steps -> testCaseSteps _testName (withCurrentDirectory _testRoot . steps)
diff --git a/test/Scope/Negative.hs b/test/Scope/Negative.hs
index 3ef4f63ca..05369d470 100644
--- a/test/Scope/Negative.hs
+++ b/test/Scope/Negative.hs
@@ -1,29 +1,40 @@
 module Scope.Negative (allTests) where
 
 import Base
+import MiniJuvix.Pipeline
 import MiniJuvix.Syntax.Concrete.Scoped.Error
 import MiniJuvix.Syntax.Concrete.Scoped.Scoper qualified as M
 
 type FailMsg = String
 
 data NegTest = NegTest
-  { name :: String,
-    relDir :: FilePath,
-    file :: FilePath,
-    checkErr :: ScopeError -> Maybe FailMsg
+  { _name :: String,
+    _relDir :: FilePath,
+    _file :: FilePath,
+    _checkErr :: ScopeError -> Maybe FailMsg
   }
 
+makeLenses ''NegTest
+
+root :: FilePath
+root = "tests/negative"
+
 testDescr :: NegTest -> TestDescr
 testDescr NegTest {..} =
-  TestDescr
-    { testName = name,
-      testRoot = root </> relDir,
-      testAssertion = Single $ do
-        p <- parseModuleIO file >>= M.scopeCheck1IO "."
-        case p of
-          Left err -> whenJust (checkErr err) assertFailure
-          Right _ -> assertFailure "The scope checker did not find an error."
-    }
+  let tRoot = root </> _relDir
+   in TestDescr
+        { _testName = _name,
+          _testRoot = tRoot,
+          _testAssertion = Single $ do
+            let entryPoint = EntryPoint tRoot (pure _file)
+            res <- runIOEither (upToScoping entryPoint)
+            let msg1 = "The scope checker did not find an error."
+            let msg2 = "An error ocurred but it was not in the scoper."
+            case mapLeft fromAJuvixError res of
+              Left (Just err) -> whenJust (_checkErr err) assertFailure
+              Left Nothing -> assertFailure msg1
+              Right _ -> assertFailure msg2
+        }
 
 allTests :: TestTree
 allTests =
@@ -31,9 +42,6 @@ allTests =
     "Scope negative tests"
     (map (mkTest . testDescr) tests)
 
-root :: FilePath
-root = "tests/negative"
-
 wrongError :: Maybe FailMsg
 wrongError = Just "Incorrect error"
 
diff --git a/test/Scope/Positive.hs b/test/Scope/Positive.hs
index e65cea8d1..e291e90e5 100644
--- a/test/Scope/Positive.hs
+++ b/test/Scope/Positive.hs
@@ -4,55 +4,70 @@ import Base
 import Data.Algorithm.Diff
 import Data.Algorithm.DiffOutput
 import Data.HashMap.Strict qualified as HashMap
+import MiniJuvix.Pipeline
+import MiniJuvix.Prelude
+import MiniJuvix.Syntax.Concrete.Parser qualified as Parser
 import MiniJuvix.Syntax.Concrete.Scoped.Pretty.Text qualified as M
-import MiniJuvix.Syntax.Concrete.Scoped.Scoper qualified as M
+import MiniJuvix.Syntax.Concrete.Scoped.Scoper qualified as Scoper
 import MiniJuvix.Syntax.Concrete.Scoped.Utils
 import Text.Show.Pretty hiding (Html)
 
 data PosTest = PosTest
-  { name :: String,
-    relDir :: FilePath,
-    file :: FilePath
+  { _name :: String,
+    _relDir :: FilePath,
+    _file :: FilePath
   }
 
+makeLenses ''PosTest
+
 root :: FilePath
 root = "tests/positive"
 
 testDescr :: PosTest -> TestDescr
 testDescr PosTest {..} =
-  TestDescr
-    { testName = name,
-      testRoot = root </> relDir,
-      testAssertion = Steps $ \step -> do
-        step "Parse"
-        p <- parseModuleIO file
+  let testRoot = root </> _relDir
+   in TestDescr
+        { _testName = _name,
+          _testRoot = testRoot,
+          _testAssertion = Steps $ \step -> do
+            let entryPoint = EntryPoint testRoot (pure _file)
 
-        step "Scope"
-        s <- scopeModuleIO p
-        let fs :: HashMap FilePath Text
-            fs =
-              HashMap.fromList
-                [ (getModuleFilePath m, M.renderPrettyCodeDefault m)
-                  | m <- toList (getAllModules s)
-                ]
+            step "Parsing"
+            p :: Parser.ParserResult <- runIO (upToParsing entryPoint)
 
-        step "Pretty"
-        let scopedPretty = M.renderPrettyCodeDefault s
-        let parsedPretty = M.renderPrettyCodeDefault p
+            let p2 = head (p ^. Parser.resultModules)
 
-        step "Parse again"
-        p' <- parseTextModuleIO scopedPretty
-        parsedPretty' <- parseTextModuleIO parsedPretty
+            step "Scoping"
+            s :: Scoper.ScoperResult <- runIO (pipelineScoper p)
 
-        step "Scope again"
-        s' <-
-          head . Scoper._resultModules
-            <$> fromRightIO' printErrorAnsi (return (Scoper.scopeCheck1Pure fs "." p'))
-        step "Checks"
-        assertEqDiff "check: scope . parse . pretty . scope . parse = scope . parse" s s'
-        assertEqDiff "check: parse . pretty . scope . parse = parse" p p'
-        assertEqDiff "check: parse . pretty . parse = parse" p parsedPretty'
-    }
+            let s2 = head (s ^. Scoper.resultModules)
+
+            let fs :: HashMap FilePath Text
+                fs =
+                  HashMap.fromList
+                    [ (getModuleFilePath m, M.renderPrettyCodeDefault m)
+                      | m <- toList (getAllModules s2)
+                    ]
+
+            let scopedPretty = M.renderPrettyCodeDefault s2
+            let parsedPretty = M.renderPrettyCodeDefault p2
+
+            step "Parsing pretty scoped"
+            let fs2 = HashMap.singleton _file scopedPretty
+            p' :: Parser.ParserResult <- (runM . runErrorIO @AJuvixError . runFilesPure fs2) (upToParsing entryPoint)
+
+            step "Parsing pretty parsed"
+            let fs3 = HashMap.singleton _file parsedPretty
+            parsedPretty' :: Parser.ParserResult <- (runM . runErrorIO @AJuvixError . runFilesPure fs3) (upToParsing entryPoint)
+
+            step "Scoping the scoped"
+            s' :: Scoper.ScoperResult <- (runM . runErrorIO @AJuvixError . runFilesPure fs) (upToScoping entryPoint)
+
+            step "Checks"
+            assertEqDiff "check: scope . parse . pretty . scope . parse = scope . parse" s s'
+            assertEqDiff "check: parse . pretty . scope . parse = parse" p p'
+            assertEqDiff "check: parse . pretty . parse = parse" p parsedPretty'
+        }
 
 assertEqDiff :: (Eq a, Show a) => String -> a -> a -> Assertion
 assertEqDiff msg a b
diff --git a/test/TypeCheck/Negative.hs b/test/TypeCheck/Negative.hs
index bd580b7d4..b8b290a32 100644
--- a/test/TypeCheck/Negative.hs
+++ b/test/TypeCheck/Negative.hs
@@ -1,6 +1,7 @@
 module TypeCheck.Negative (allTests) where
 
 import Base
+import MiniJuvix.Pipeline
 import MiniJuvix.Syntax.MicroJuvix.Error
 import MiniJuvix.Syntax.MicroJuvix.TypeChecker qualified as T
 import MiniJuvix.Translation.AbstractToMicroJuvix qualified as A
@@ -8,29 +9,29 @@ import MiniJuvix.Translation.AbstractToMicroJuvix qualified as A
 type FailMsg = String
 
 data NegTest = NegTest
-  { name :: String,
-    relDir :: FilePath,
-    file :: FilePath,
-    checkErr :: [TypeCheckerError] -> Maybe FailMsg
+  { _name :: String,
+    _relDir :: FilePath,
+    _file :: FilePath,
+    _checkErr :: TypeCheckerErrors -> Maybe FailMsg
   }
 
 testDescr :: NegTest -> TestDescr
 testDescr NegTest {..} =
-  TestDescr
-    { testName = name,
-      testRoot = root </> relDir,
-      testAssertion = Single $ do
-        result <-
-          parseModuleIO file
-            >>= scopeModuleIO
-            >>= translateModuleIO
-            >>| A.translateModule
-            >>| T.checkModule
+  let tRoot = root </> _relDir
+   in TestDescr
+        { _testName = _name,
+          _testRoot = tRoot,
+          _testAssertion = Single $ do
+            let entryPoint = EntryPoint tRoot (pure _file)
 
-        case result of
-          Left es -> whenJust (checkErr (toList es)) assertFailure
-          Right _ -> assertFailure "The type checker did not find an error."
-    }
+            result <- runIOEither (upToMicroJuvixTyped entryPoint)
+            let msg1 = "The type checker did not find an error."
+            let msg2 = "An error ocurred but it was not in the type checker."
+            case mapLeft fromAJuvixError result of
+              Left (Just err) -> whenJust (_checkErr err) assertFailure
+              Left Nothing -> assertFailure msg1
+              Right _ -> assertFailure msg2
+        }
 
 allTests :: TestTree
 allTests =