Add tests for basic column type conversion errors

devenv.sh

@@ -4,6 +4,5 @@
 # Run tests
 function rt ()
 {
-    cabal-dev build
-    ./dist/build/test/test
+    cabal-dev build && ./dist/build/test/test
 }

test/Errors.hs

@@ -1,8 +1,11 @@
+{-# LANGUAGE ScopedTypeVariables #-}
 
 module Errors (
     testErrorsColumns
   ) where
 
+import Prelude hiding (catch)
+import Control.Exception
 import Common
 
 testErrorsColumns :: TestEnv -> Test
@@ -13,6 +16,13 @@ testErrorsColumns TestEnv{..} = TestCase $ do
   assertEqual "row count" 1 (length rows)
   assertEqual "string" (Only "test string") (head rows)
   -- Mismatched number of output columns (selects two, dest type has 1 field)
-  _rows <- query_ conn "SELECT id,t FROM cols" :: IO [Only Int]
+  convFailedTriggered <-
+    catch ((query_ conn "SELECT id,t FROM cols" :: IO [Only Int]) >> return False)
+    (\(_ :: ResultError) -> return True)
+  assertBool "exception" convFailedTriggered
+  -- Same as above but the other way round (select 1, dst has two)
+  convFailed <-
+    catch ((query_ conn "SELECT id FROM cols" :: IO [(Int, String)]) >> return False)
+    (\(_ :: ResultError) -> return True)
+  assertBool "exception" convFailed
   return ()
-