diff --git a/bower.json b/bower.json
index 64771f5..b93f69e 100644
--- a/bower.json
+++ b/bower.json
@@ -26,12 +26,19 @@
     "output"
   ],
   "dependencies": {
-    "purescript-arrays": "~0.4.0",
-    "purescript-either": "~0.2.0",
-    "purescript-foreign": "~0.7.0",
-    "purescript-foldable-traversable": "~0.4.0",
-    "purescript-transformers": "~0.8.0",
-    "purescript-aff": "~0.16.0",
-    "purescript-integers": "~0.2.0"
+    "purescript-arrays": "^1.0.0",
+    "purescript-either": "^1.0.0",
+    "purescript-foreign": "^1.0.0",
+    "purescript-foldable-traversable": "^1.0.0",
+    "purescript-transformers": "^1.0.0",
+    "purescript-aff": "^1.0.0",
+    "purescript-integers": "^1.0.0",
+    "purescript-datetime": "^1.0.0",
+    "purescript-unsafe-coerce": "^1.0.0",
+    "purescript-nullable": "^1.0.1"
+  },
+  "devDependencies": {
+    "purescript-spec": "~0.8.0",
+    "purescript-generics": "~1.0.0"
   }
 }
diff --git a/schema.sql b/schema.sql
index 42f979e..3fa6ae6 100644
--- a/schema.sql
+++ b/schema.sql
@@ -4,3 +4,5 @@ CREATE TABLE artist (
     name text NOT NULL,
     year int NOT NULL
 );
+
+CREATE table types (timestamp_no_tz timestamp without time zone);
diff --git a/src/Database/Postgres.purs b/src/Database/Postgres.purs
index 83a6541..3130a69 100644
--- a/src/Database/Postgres.purs
+++ b/src/Database/Postgres.purs
@@ -19,7 +19,7 @@ module Database.Postgres
 import Prelude
 import Control.Monad.Eff (Eff)
 import Data.Either (either)
-import Data.Function (Fn2(), runFn2)
+import Data.Function.Uncurried (Fn2(), runFn2)
 import Data.Array ((!!))
 import Data.Foreign (Foreign, ForeignError)
 import Data.Foreign.Class (class IsForeign, read)
diff --git a/src/Database/Postgres/SqlValue.js b/src/Database/Postgres/SqlValue.js
deleted file mode 100644
index 83b4cbc..0000000
--- a/src/Database/Postgres/SqlValue.js
+++ /dev/null
@@ -1,9 +0,0 @@
-'use strict';
-
-// module Database.Postgres.SqlValue
-
-exports.unsafeToSqlValue = function (x) {
-  return x;
-}
-
-exports.nullSqlValue = null;
diff --git a/src/Database/Postgres/SqlValue.purs b/src/Database/Postgres/SqlValue.purs
index 87b09fa..301eda8 100644
--- a/src/Database/Postgres/SqlValue.purs
+++ b/src/Database/Postgres/SqlValue.purs
@@ -4,9 +4,15 @@ module Database.Postgres.SqlValue
   , toSql
   ) where
 
-import Prelude ((<<<))
+import Prelude
+import Data.Enum (fromEnum)
 import Data.Int (toNumber)
-import Data.Maybe (Maybe(..))
+import Data.Maybe (Maybe)
+import Data.Date (year, month, day)
+import Data.DateTime (DateTime(DateTime))
+import Data.Time (hour, minute, second)
+import Unsafe.Coerce (unsafeCoerce)
+import Data.Nullable (toNullable)
 
 foreign import data SqlValue :: *
 
@@ -14,18 +20,28 @@ class IsSqlValue a where
   toSql :: a -> SqlValue
 
 instance isSqlValueString :: IsSqlValue String where
-  toSql = unsafeToSqlValue
+  toSql = unsafeCoerce
 
 instance isSqlValueNumber :: IsSqlValue Number where
-  toSql = unsafeToSqlValue
+  toSql = unsafeCoerce
 
 instance isSqlValueInt :: IsSqlValue Int where
-  toSql = unsafeToSqlValue <<< toNumber
+  toSql = unsafeCoerce <<< toNumber
 
 instance isSqlValueMaybe :: (IsSqlValue a) => IsSqlValue (Maybe a) where
-  toSql Nothing = nullSqlValue
-  toSql (Just x) = toSql x
-
-foreign import unsafeToSqlValue :: forall a. a -> SqlValue
-
-foreign import nullSqlValue :: SqlValue
+  toSql = unsafeCoerce <<< toNullable <<< (toSql <$> _)
+
+instance isSqlValueDateTime :: IsSqlValue DateTime where
+  toSql = toSql <<< format
+    where
+      format (DateTime d t)
+        = show (fromEnum (year d)) <> "-"
+        <> zeroPad (fromEnum (month d)) <> "-"
+        <> zeroPad (fromEnum (day d)) <> " "
+        <> zeroPad (fromEnum (hour t)) <> ":"
+        <> zeroPad (fromEnum (minute t)) <> ":"
+        <> zeroPad (fromEnum (second t))
+
+      zeroPad :: Int -> String
+      zeroPad i | i < 10 = "0" <> (show i)
+      zeroPad i = show i
diff --git a/test/Main.purs b/test/Main.purs
index 13a23aa..4d3565a 100644
--- a/test/Main.purs
+++ b/test/Main.purs
@@ -1,42 +1,42 @@
 module Test.Main where
 
-import Control.Monad.Eff.Console as C
-import Control.Monad.Aff (Aff, apathize, attempt, runAff)
-import Control.Monad.Aff.Console (log, print)
+import Prelude
+import Control.Monad.Aff (Aff, apathize, attempt)
 import Control.Monad.Eff (Eff)
 import Control.Monad.Eff.Class (liftEff)
 import Control.Monad.Eff.Console (CONSOLE)
 import Control.Monad.Eff.Exception (error)
 import Control.Monad.Error.Class (throwError)
+import Data.Array (length)
+import Data.Date (canonicalDate)
+import Data.DateTime (DateTime(..))
+import Data.Date.Component (Month(..))
+import Data.Enum (toEnum)
+import Data.Time (Time(..))
 import Data.Either (either)
-import Data.Foldable (foldMap)
+import Data.Foreign (Foreign)
+import Data.JSDate (toDateTime)
+import Data.Maybe (Maybe(Nothing, Just), maybe)
 import Data.Foreign.Class (class IsForeign, readProp)
-import Data.Maybe (Maybe)
-import Database.Postgres (DB, Query(Query), queryOne_, execute_, withConnection, query, withClient, end, query_, connect, queryValue_, disconnect, mkConnectionString)
+import Data.Generic (class Generic, gEq)
+import Database.Postgres (DB, Query(Query), queryOne_, execute, execute_, withConnection, query, withClient, end, query_, connect, queryValue_, mkConnectionString)
 import Database.Postgres.SqlValue (toSql)
 import Database.Postgres.Transaction (withTransaction)
-import Prelude (class Show, Unit, return, ($), bind, show, (<>), void, flip, (>>>), const)
+import Node.Process (PROCESS)
 
-main :: forall eff. Eff ( console :: CONSOLE , db :: DB | eff ) Unit
-main = runAff C.print (const $ C.log "All ok") $ do
-  print $ "connecting to " <> mkConnectionString connectionInfo <> "..."
-  exampleUsingWithConnection
-  exampleLowLevel
+import Unsafe.Coerce (unsafeCoerce)
 
-  res <- attempt exampleError
-  either (const $ log "got an error, like we should") (const $ log "FAIL") res
-
-  exampleQueries
-
-  exampleTransaction
-
-  liftEff $ disconnect
+import Test.Spec (describe, it)
+import Test.Spec.Runner (run)
+import Test.Spec.Assertions (fail, shouldEqual)
+import Test.Spec.Reporter.Console (consoleReporter)
 
 data Artist = Artist
   { name :: String
   , year :: Int
   }
 
+connectionInfo :: { host :: String, db :: String, port :: Int, user :: String, password :: String }
 connectionInfo =
   { host: "localhost"
   , db: "test"
@@ -45,22 +45,84 @@ connectionInfo =
   , password: "test"
   }
 
-exampleUsingWithConnection :: forall eff. Aff (console :: C.CONSOLE, db :: DB | eff) Unit
-exampleUsingWithConnection = withConnection connectionInfo $ \c -> do
-  execute_ (Query "delete from artist") c
-  execute_ (Query "insert into artist values ('Led Zeppelin', 1968)") c
-  execute_ (Query "insert into artist values ('Deep Purple', 1968)") c
-  year <- queryValue_ (Query "insert into artist values ('Fairport Convention', 1967) returning year" :: Query Number) c
-  print (show year)
-  artists <- query_ (Query "select * from artist" :: Query Artist) c
-  printRows artists
-
-exampleLowLevel :: forall eff. Aff (console :: C.CONSOLE, db :: DB | eff) Unit
-exampleLowLevel = do
-  client <- connect connectionInfo
-  artists <- query_ (Query "select * from artist order by name desc" :: Query Artist) client
-  printRows artists
-  liftEff $ end client
+main :: Eff (process :: PROCESS, console :: CONSOLE , db :: DB) Unit
+main = run [consoleReporter] do
+  describe "connection string" do
+    it "should build one from the connection record" do
+      mkConnectionString connectionInfo `shouldEqual` "postgres://testuser:test@localhost:5432/test"
+
+  describe "withConnection" do
+    it "Returns a connection" do
+      withConnection connectionInfo $ \c -> do
+        execute_ (Query "delete from artist") c
+        execute_ (Query "insert into artist values ('Led Zeppelin', 1968)") c
+        execute_ (Query "insert into artist values ('Deep Purple', 1968)") c
+        let
+          q :: Query Int
+          q = Query "insert into artist values ('Fairport Convention', 1967) returning year"
+
+        year <- queryValue_ q c
+        year `shouldEqual` (Just 1967)
+
+        artists <- query_ (Query "select * from artist" :: Query Artist) c
+        length artists `shouldEqual` 3
+
+  describe "Low level API" do
+    it "Can be used to manage connections manually" do
+      client <- connect connectionInfo
+      execute_ (Query "delete from artist") client
+      execute_ (Query "insert into artist values ('Led Zeppelin', 1968)") client
+
+      artists <- query_ (Query "select * from artist order by name desc" :: Query Artist) client
+      artists `shouldEqual` [Artist { name: "Led Zeppelin", year: 1968 }]
+
+      liftEff $ end client
+
+  describe "Error handling" do
+    it "When query cannot be converted to the requested data type we get an error" do
+      res <- attempt exampleError
+      either (const $ pure unit) (const $ fail "FAIL") res
+
+  describe "Query params" do
+    it "Select using a query param" do
+      withClient connectionInfo $ \c -> do
+        execute_ (Query "delete from artist") c
+        execute_ (Query "insert into artist values ('Led Zeppelin', 1968)") c
+        execute_ (Query "insert into artist values ('Deep Purple', 1968)") c
+        execute_ (Query "insert into artist values ('Toto', 1977)") c
+        artists <- query (Query "select * from artist where name = $1" :: Query Artist) [toSql "Toto"] c
+        length artists `shouldEqual` 1
+
+        noRows <- query (Query "select * from artist where name = $1" :: Query Artist) [toSql "FAIL"] c
+        length noRows `shouldEqual` 0
+
+  describe "data types" do
+    it "datetimes can be inserted" do
+      withConnection connectionInfo \c -> do
+        execute_ (Query "delete from types") c
+        let date = canonicalDate <$> toEnum 2016 <*> Just January <*> toEnum 25
+            time = Time <$> toEnum 23 <*> toEnum 1 <*> toEnum 59 <*> toEnum 0
+            dt = DateTime <$> date <*> time
+        maybe (fail "Not a datetime") (\ts -> do
+          execute (Query "insert into types(timestamp_no_tz) VALUES ($1)") [toSql ts] c
+          ts' <- queryValue_ (Query "select timestamp_no_tz at time zone 'UTC' from types" :: Query Foreign) c
+          let res = unsafeCoerce <$> ts' >>= toDateTime
+          res `shouldEqual` (Just ts)
+        ) dt
+
+
+  describe "transactions" do 
+    it "does not commit after an error inside a transation" do
+      withConnection connectionInfo $ \c -> do
+        execute_ (Query "delete from artist") c
+        apathize $ tryInsert c
+        one <- queryOne_ (Query "select * from artist" :: Query Artist) c
+
+        one `shouldEqual` Nothing
+          where
+          tryInsert = withTransaction $ \c -> do
+            execute_ (Query "insert into artist values ('Not there', 1999)") c
+            throwError $ error "fail"
 
 exampleError :: forall eff. Aff (db :: DB | eff) (Maybe Artist)
 exampleError = withConnection connectionInfo $ \c -> do
@@ -68,36 +130,16 @@ exampleError = withConnection connectionInfo $ \c -> do
   execute_ (Query "insert into artist values ('Led Zeppelin', 1968)") c
   queryOne_ (Query "select year from artist") c
 
-exampleQueries :: forall eff. Aff (console :: C.CONSOLE, db :: DB | eff) Unit
-exampleQueries = withClient connectionInfo $ \c -> do
-  log "Example queries with params:"
-  execute_ (Query "delete from artist") c
-  execute_ (Query "insert into artist values ('Led Zeppelin', 1968)") c
-  execute_ (Query "insert into artist values ('Deep Purple', 1968)") c
-  execute_ (Query "insert into artist values ('Toto', 1977)") c
-  artists <- query (Query "select * from artist where name = $1" :: Query Artist) [toSql "Toto"] c
-  printRows artists
-
-exampleTransaction :: forall eff. Aff (console :: C.CONSOLE, db :: DB | eff) Unit
-exampleTransaction = withConnection connectionInfo $ \c -> do
-  execute_ (Query "delete from artist") c
-  apathize $ tryInsert c
-  one <- queryOne_ (Query "select * from artist" :: Query Artist) c
-  void $ print one
-    where
-    tryInsert = withTransaction $ \c -> do
-      execute_ (Query "insert into artist values ('Not there', 1999)") c
-      throwError $ error "fail"
-
-printRows :: forall a eff. (Show a) => Array a -> Aff (console :: C.CONSOLE | eff) Unit
-printRows rows = void $ log $ "result:\n" <> foldMap stringify rows
-  where stringify = show >>> flip (<>) "\n"
-
 instance artistShow :: Show Artist where
   show (Artist p) = "Artist (" <> p.name <> ", " <> show p.year <> ")"
 
+derive instance genericArtist :: Generic Artist
+
+instance eqArtist :: Eq Artist where
+  eq = gEq
+
 instance artistIsForeign :: IsForeign Artist where
   read obj = do
     n <- readProp "name" obj
     y <- readProp "year" obj
-    return $ Artist { name: n, year: y }
+    pure $ Artist { name: n, year: y }