bloodhound/tests/tests.hs

{-# LANGUAGE DeriveGeneric       #-}
{-# LANGUAGE OverloadedStrings   #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}
module Main where

import           Control.Applicative
import           Control.Monad
import           Control.Monad.Reader
import           Data.Aeson
import qualified Data.HashMap.Strict             as HM
import           Data.List                       (nub)
import           Data.List.NonEmpty              (NonEmpty (..))
import qualified Data.List.NonEmpty              as NE
import qualified Data.Map.Strict                 as M
import           Data.Text                       (Text)
import qualified Data.Text                       as T
import           Data.Time.Calendar              (Day (..))
import           Data.Time.Clock                 (UTCTime (..),
                                                  secondsToDiffTime)
import qualified Data.Vector                     as V
import           Database.Bloodhound
import           GHC.Generics                    (Generic)
import           Network.HTTP.Client
import qualified Network.HTTP.Types.Status       as NHTS
import           Prelude                         hiding (filter, putStrLn)
import           Test.Hspec
import           Test.QuickCheck.Property.Monoid

import           Test.Hspec.QuickCheck           (prop)
import           Test.QuickCheck

testServer  :: Server
testServer  = Server "http://localhost:9200"
testIndex   :: IndexName
testIndex   = IndexName "bloodhound-tests-twitter-1"
testMapping :: MappingName
testMapping = MappingName "tweet"

withTestEnv :: BH IO a -> IO a
withTestEnv = withBH defaultManagerSettings testServer

validateStatus :: Response body -> Int -> Expectation
validateStatus resp expected =
  (NHTS.statusCode $ responseStatus resp)
  `shouldBe` (expected :: Int)

createExampleIndex :: BH IO Reply
createExampleIndex = createIndex defaultIndexSettings testIndex
deleteExampleIndex :: BH IO Reply
deleteExampleIndex = deleteIndex testIndex

data ServerVersion = ServerVersion Int Int Int deriving (Show, Eq, Ord)

es14 :: ServerVersion
es14 = ServerVersion 1 4 0

es13 :: ServerVersion
es13 = ServerVersion 1 3 0

es12 :: ServerVersion
es12 = ServerVersion 1 2 0

es11 :: ServerVersion
es11 = ServerVersion 1 1 0

es10 :: ServerVersion
es10 = ServerVersion 1 0 0

serverBranch :: ServerVersion -> ServerVersion
serverBranch (ServerVersion majorVer minorVer patchVer) =
  ServerVersion majorVer minorVer patchVer

mkServerVersion :: [Int] -> Maybe ServerVersion
mkServerVersion [majorVer, minorVer, patchVer] =
  Just (ServerVersion majorVer minorVer patchVer)
mkServerVersion _                 = Nothing

getServerVersion :: IO (Maybe ServerVersion)
getServerVersion = liftM extractVersion (withTestEnv getStatus)
  where
    version'                    = T.splitOn "." . number . version
    toInt                       = read . T.unpack
    parseVersion v              = map toInt (version' v)
    extractVersion              = join . liftM (mkServerVersion . parseVersion)

testServerBranch :: IO (Maybe ServerVersion)
testServerBranch = getServerVersion >>= \v -> return $ liftM serverBranch v

atleast :: ServerVersion -> IO Bool
atleast v = testServerBranch >>= \x -> return $ x >= Just (serverBranch v)

atmost :: ServerVersion -> IO Bool
atmost v = testServerBranch >>= \x -> return $ x <= Just (serverBranch v)

is :: ServerVersion -> IO Bool
is v = testServerBranch >>= \x -> return $ x == Just (serverBranch v)

when' :: Monad m => m Bool -> m () -> m ()
when' b f = b >>= \x -> when x f

data Location = Location { lat :: Double
                         , lon :: Double } deriving (Eq, Generic, Show)

data Tweet = Tweet { user     :: Text
                   , postDate :: UTCTime
                   , message  :: Text
                   , age      :: Int
                   , location :: Location }
           deriving (Eq, Generic, Show)

instance ToJSON   Tweet
instance FromJSON Tweet
instance ToJSON   Location
instance FromJSON Location

data TweetMapping = TweetMapping deriving (Eq, Show)

instance ToJSON TweetMapping where
  toJSON TweetMapping =
    object ["tweet" .=
      object ["properties" .=
        object ["location" .= object ["type" .= ("geo_point" :: Text)]]]]

exampleTweet :: Tweet
exampleTweet = Tweet { user     = "bitemyapp"
                     , postDate = UTCTime
                                  (ModifiedJulianDay 55000)
                                  (secondsToDiffTime 10)
                     , message  = "Use haskell!"
                     , age      = 10000
                     , location = Location 40.12 (-71.34) }

otherTweet :: Tweet
otherTweet = Tweet { user     = "notmyapp"
                   , postDate = UTCTime
                                (ModifiedJulianDay 55000)
                                (secondsToDiffTime 11)
                   , message  = "Use haskell!"
                   , age      = 1000
                   , location = Location 40.12 (-71.34) }

insertData :: BH IO ()
insertData = do
  _ <- deleteExampleIndex
  _ <- createExampleIndex
  _ <- putMapping testIndex testMapping TweetMapping
  _ <- indexDocument testIndex testMapping exampleTweet (DocId "1")
  _ <- refreshIndex testIndex
  return ()

insertOther :: BH IO ()
insertOther = do
  _ <- indexDocument testIndex testMapping otherTweet (DocId "2")
  _ <- refreshIndex testIndex
  return ()

searchTweet :: Search -> BH IO (Either String Tweet)
searchTweet search = do
  reply <- searchByIndex testIndex search
  let result = eitherDecode (responseBody reply) :: Either String (SearchResult Tweet)
  let myTweet = fmap (hitSource . head . hits . searchHits) result
  return myTweet

searchExpectNoResults :: Search -> BH IO ()
searchExpectNoResults search = do
  reply <- searchByIndex testIndex search
  let result = eitherDecode (responseBody reply) :: Either String (SearchResult Tweet)
  let emptyHits = fmap (hits . searchHits) result
  liftIO $
    emptyHits `shouldBe` Right []

searchExpectAggs :: Search -> BH IO ()
searchExpectAggs search = do
  reply <- searchAll search
  let isEmpty x = return (M.null x)
  let result = decode (responseBody reply) :: Maybe (SearchResult Tweet)
  liftIO $
    (result >>= aggregations >>= isEmpty) `shouldBe` Just False

searchValidBucketAgg :: (BucketAggregation a, FromJSON a, Show a) => Search -> Text -> (Text -> AggregationResults -> Maybe (Bucket a)) -> BH IO ()
searchValidBucketAgg search aggKey extractor = do
  reply <- searchAll search
  let bucketDocs = docCount . head . buckets
  let result = decode (responseBody reply) :: Maybe (SearchResult Tweet)
  let count = result >>= aggregations >>= extractor aggKey >>= \x -> return (bucketDocs x)
  liftIO $
    count `shouldBe` Just 1

searchTermsAggHint :: [ExecutionHint] -> BH IO ()
searchTermsAggHint hints = do
      let terms hint = TermsAgg $ (mkTermsAggregation "user") { termExecutionHint = Just hint }
      let search hint = mkAggregateSearch Nothing $ mkAggregations "users" $ terms hint
      forM_ hints $ searchExpectAggs . search
      forM_ hints (\x -> searchValidBucketAgg (search x) "users" toTerms)

searchTweetHighlight :: Search -> BH IO (Either String (Maybe HitHighlight))
searchTweetHighlight search = do
  reply <- searchByIndex testIndex search
  let result = eitherDecode (responseBody reply) :: Either String (SearchResult Tweet)
  let myHighlight = fmap (hitHighlight . head . hits . searchHits) result
  return myHighlight

data BulkTest = BulkTest { name :: Text } deriving (Eq, Generic, Show)
instance FromJSON BulkTest
instance ToJSON BulkTest

noDuplicates :: Eq a => [a] -> Bool
noDuplicates xs = nub xs == xs

instance Arbitrary RegexpFlags where
  arbitrary = oneof [ pure AllRegexpFlags
                    , pure NoRegexpFlags
                    , SomeRegexpFlags <$> arbitrary
                    ]

instance Arbitrary a => Arbitrary (NonEmpty a) where
  arbitrary = liftA2 (:|) arbitrary arbitrary

instance Arbitrary RegexpFlag where
  arbitrary = oneof [ pure AnyString
                    , pure Automaton
                    , pure Complement
                    , pure Empty
                    , pure Intersection
                    , pure Interval
                    ]

arbitraryScore :: Gen Score
arbitraryScore = fmap getPositive <$> arbitrary

instance Arbitrary Text where
  arbitrary = T.pack <$> arbitrary

instance (Arbitrary k, Arbitrary v, Ord k) => Arbitrary (M.Map k v) where
  arbitrary = M.fromList <$> arbitrary

instance Arbitrary IndexName where
  arbitrary = IndexName <$> arbitrary

instance Arbitrary MappingName where
  arbitrary = MappingName <$> arbitrary

instance Arbitrary DocId where
  arbitrary = DocId <$> arbitrary

instance Arbitrary a => Arbitrary (Hit a) where
  arbitrary = Hit <$> arbitrary
                  <*> arbitrary
                  <*> arbitrary
                  <*> arbitraryScore
                  <*> arbitrary
                  <*> arbitrary


instance Arbitrary a => Arbitrary (SearchHits a) where
  arbitrary = do
    tot <- getPositive <$> arbitrary
    score <- arbitraryScore
    hs <- arbitrary
    return $ SearchHits tot score hs

main :: IO ()
main = hspec $ do

  describe "index create/delete API" $ do
    it "creates and then deletes the requested index" $ withTestEnv $ do
      -- priming state.
      _ <- deleteExampleIndex
      resp <- createExampleIndex
      deleteResp <- deleteExampleIndex
      liftIO $ do
        validateStatus resp 200
        validateStatus deleteResp 200


  describe "document API" $ do
    it "indexes, gets, and then deletes the generated document" $ withTestEnv $ do
      _ <- insertData
      docInserted <- getDocument testIndex testMapping (DocId "1")
      let newTweet = eitherDecode
                     (responseBody docInserted) :: Either String (EsResult Tweet)
      liftIO $ (fmap _source newTweet `shouldBe` Right exampleTweet)


  describe "bulk API" $ do
    it "inserts all documents we request" $ withTestEnv $ do
      _ <- insertData
      let firstTest = BulkTest "blah"
      let secondTest = BulkTest "bloo"
      let firstDoc = BulkIndex testIndex
                     testMapping (DocId "2") (toJSON firstTest)
      let secondDoc = BulkCreate testIndex
                     testMapping (DocId "3") (toJSON secondTest)
      let stream = V.fromList [firstDoc, secondDoc]
      _ <- bulk stream
      _ <- refreshIndex testIndex
      fDoc <- getDocument testIndex testMapping (DocId "2")
      sDoc <- getDocument testIndex testMapping (DocId "3")
      let maybeFirst  = eitherDecode $ responseBody fDoc :: Either String (EsResult BulkTest)
      let maybeSecond = eitherDecode $ responseBody sDoc :: Either String (EsResult BulkTest)
      liftIO $ do
        fmap _source maybeFirst `shouldBe` Right firstTest
        fmap _source maybeSecond `shouldBe` Right secondTest


  describe "query API" $ do
    it "returns document for term query and identity filter" $ withTestEnv $ do
      _ <- insertData
      let query = TermQuery (Term "user" "bitemyapp") Nothing
      let filter = IdentityFilter <&&> IdentityFilter
      let search = mkSearch (Just query) (Just filter)
      myTweet <- searchTweet search
      liftIO $
        myTweet `shouldBe` Right exampleTweet

    it "returns document for terms query and identity filter" $ withTestEnv $ do
      _ <- insertData
      let query = TermsQuery (NE.fromList [(Term "user" "bitemyapp")])
      let filter = IdentityFilter <&&> IdentityFilter
      let search = mkSearch (Just query) (Just filter)
      myTweet <- searchTweet search
      liftIO $
        myTweet `shouldBe` Right exampleTweet

    it "returns document for match query" $ withTestEnv $ do
      _ <- insertData
      let query = QueryMatchQuery $ mkMatchQuery (FieldName "user") (QueryString "bitemyapp")
      let search = mkSearch (Just query) Nothing
      myTweet <- searchTweet search
      liftIO $
        myTweet `shouldBe` Right exampleTweet

    it "returns document for multi-match query" $ withTestEnv $ do
      _ <- insertData
      let fields = [FieldName "user", FieldName "message"]
      let query = QueryMultiMatchQuery $ mkMultiMatchQuery fields (QueryString "bitemyapp")
      let search = mkSearch (Just query) Nothing
      myTweet <- searchTweet search
      liftIO $
        myTweet `shouldBe` Right exampleTweet

    it "returns document for bool query" $ withTestEnv $ do
      _ <- insertData
      let innerQuery = QueryMatchQuery $
                       mkMatchQuery (FieldName "user") (QueryString "bitemyapp")
      let query = QueryBoolQuery $
                  mkBoolQuery [innerQuery] [] []
      let search = mkSearch (Just query) Nothing
      myTweet <- searchTweet search
      liftIO $
        myTweet `shouldBe` Right exampleTweet

    it "returns document for boosting query" $ withTestEnv $ do
      _ <- insertData
      let posQuery = QueryMatchQuery $ mkMatchQuery (FieldName "user") (QueryString "bitemyapp")
      let negQuery = QueryMatchQuery $ mkMatchQuery (FieldName "user") (QueryString "notmyapp")
      let query = QueryBoostingQuery $ BoostingQuery posQuery negQuery (Boost 0.2)
      let search = mkSearch (Just query) Nothing
      myTweet <- searchTweet search
      liftIO $
        myTweet `shouldBe` Right exampleTweet

    it "returns document for common terms query" $ withTestEnv $ do
      _ <- insertData
      let query = QueryCommonTermsQuery $
                  CommonTermsQuery (FieldName "user")
                  (QueryString "bitemyapp")
                  (CutoffFrequency 0.0001)
                  Or Or Nothing Nothing Nothing Nothing
      let search = mkSearch (Just query) Nothing
      myTweet <- searchTweet search
      liftIO $
        myTweet `shouldBe` Right exampleTweet


  describe "sorting" $ do
    it "returns documents in the right order" $ withTestEnv $ do
      _ <- insertData
      _ <- insertOther
      let sortSpec = DefaultSortSpec $ mkSort (FieldName "age") Ascending
      let search = Search Nothing
                   (Just IdentityFilter) (Just [sortSpec]) Nothing Nothing
                   False (From 0) (Size 10)
      reply <- searchByIndex testIndex search
      let result = eitherDecode (responseBody reply) :: Either String (SearchResult Tweet)
      let myTweet = fmap (hitSource . head . hits . searchHits) result
      liftIO $
        myTweet `shouldBe` Right otherTweet


  describe "filtering API" $ do
    it "returns document for composed boolmatch and identity" $ withTestEnv $ do
      _ <- insertData
      let queryFilter = BoolFilter (MustMatch (Term "user" "bitemyapp") False)
                        <&&> IdentityFilter
      let search = mkSearch Nothing (Just queryFilter)
      myTweet <- searchTweet search
      liftIO $
        myTweet `shouldBe` Right exampleTweet

    it "returns document for term filter" $ withTestEnv $ do
      _ <- insertData
      let termFilter = TermFilter (Term "user" "bitemyapp") False
      let search = mkSearch Nothing (Just termFilter)
      myTweet <- searchTweet search
      liftIO $
        myTweet `shouldBe` Right exampleTweet

    it "returns document for existential filter" $ withTestEnv $ do
      _ <- insertData
      let search = mkSearch Nothing (Just (ExistsFilter (FieldName "user")))
      myTweet <- searchTweet search
      liftIO $
        myTweet `shouldBe` Right exampleTweet

    it "returns document for geo boundingbox filter" $ withTestEnv $ do
      _ <- insertData
      let box = GeoBoundingBox (LatLon 40.73 (-74.1)) (LatLon 40.10 (-71.12))
      let bbConstraint = GeoBoundingBoxConstraint (FieldName "tweet.location") box False GeoFilterMemory
      let geoFilter = GeoBoundingBoxFilter bbConstraint
      let search = mkSearch Nothing (Just geoFilter)
      myTweet <- searchTweet search
      liftIO $
        myTweet `shouldBe` Right exampleTweet

    it "doesn't return document for nonsensical boundingbox filter" $ withTestEnv $ do
      _ <- insertData
      let box          = GeoBoundingBox (LatLon 0.73 (-4.1)) (LatLon 0.10 (-1.12))
      let bbConstraint = GeoBoundingBoxConstraint (FieldName "tweet.location") box False GeoFilterMemory
      let geoFilter    = GeoBoundingBoxFilter bbConstraint
      let search       = mkSearch Nothing (Just geoFilter)
      searchExpectNoResults search

    it "returns document for geo distance filter" $ withTestEnv $ do
      _ <- insertData
      let geoPoint = GeoPoint (FieldName "tweet.location") (LatLon 40.12 (-71.34))
      let distance = Distance 10.0 Miles
      let optimizeBbox = OptimizeGeoFilterType GeoFilterMemory
      let geoFilter = GeoDistanceFilter geoPoint distance SloppyArc optimizeBbox False
      let search = mkSearch Nothing (Just geoFilter)
      myTweet <- searchTweet search
      liftIO $
        myTweet `shouldBe` Right exampleTweet

    it "returns document for geo distance range filter" $ withTestEnv $ do
      _ <- insertData
      let geoPoint = GeoPoint (FieldName "tweet.location") (LatLon 40.12 (-71.34))
      let distanceRange = DistanceRange (Distance 0.0 Miles) (Distance 10.0 Miles)
      let geoFilter = GeoDistanceRangeFilter geoPoint distanceRange
      let search = mkSearch Nothing (Just geoFilter)
      myTweet <- searchTweet search
      liftIO $
        myTweet `shouldBe` Right exampleTweet

    it "doesn't return document for wild geo distance range filter" $ withTestEnv $ do
      _ <- insertData
      let geoPoint = GeoPoint (FieldName "tweet.location") (LatLon 40.12 (-71.34))
      let distanceRange = DistanceRange (Distance 100.0 Miles) (Distance 1000.0 Miles)
      let geoFilter = GeoDistanceRangeFilter geoPoint distanceRange
      let search = mkSearch Nothing (Just geoFilter)
      searchExpectNoResults search

    it "returns document for geo polygon filter" $ withTestEnv $ do
      _ <- insertData
      let points = [LatLon 40.0 (-70.00),
                    LatLon 40.0 (-72.00),
                    LatLon 41.0 (-70.00),
                    LatLon 41.0 (-72.00)]
      let geoFilter = GeoPolygonFilter (FieldName "tweet.location") points
      let search = mkSearch Nothing (Just geoFilter)
      myTweet <- searchTweet search
      liftIO $
        myTweet `shouldBe` Right exampleTweet

    it "doesn't return document for bad geo polygon filter" $ withTestEnv $ do
      _ <- insertData
      let points = [LatLon 40.0 (-70.00),
                    LatLon 40.0 (-71.00),
                    LatLon 41.0 (-70.00),
                    LatLon 41.0 (-71.00)]
      let geoFilter = GeoPolygonFilter (FieldName "tweet.location") points
      let search = mkSearch Nothing (Just geoFilter)
      searchExpectNoResults search

    it "returns document for ids filter" $ withTestEnv $ do
      _ <- insertData
      let filter = IdsFilter (MappingName "tweet") [DocId "1"]
      let search = mkSearch Nothing (Just filter)
      myTweet <- searchTweet search
      liftIO $
        myTweet `shouldBe` Right exampleTweet

    it "returns document for Double range filter" $ withTestEnv $ do
      _ <- insertData
      let filter = RangeFilter (FieldName "age")
                   (RangeDoubleGtLt (GreaterThan 1000.0) (LessThan 100000.0))
                   RangeExecutionIndex False
      let search = mkSearch Nothing (Just filter)
      myTweet <- searchTweet search
      liftIO $
        myTweet `shouldBe` Right exampleTweet

    it "returns document for UTCTime date filter" $ withTestEnv $ do
      _ <- insertData
      let filter = RangeFilter (FieldName "postDate")
                   (RangeDateGtLt
                    (GreaterThanD (UTCTime
                                (ModifiedJulianDay 55000)
                                (secondsToDiffTime 9)))
                    (LessThanD (UTCTime
                                (ModifiedJulianDay 55000)
                                (secondsToDiffTime 11))))
                   RangeExecutionIndex False
      let search = mkSearch Nothing (Just filter)
      myTweet <- searchTweet search
      liftIO $
        myTweet `shouldBe` Right exampleTweet


    it "returns document for regexp filter" $ withTestEnv $ do
      _ <- insertData
      let filter = RegexpFilter (FieldName "user") (Regexp "bite.*app")
                   AllRegexpFlags (CacheName "test") False (CacheKey "key")
      let search = mkSearch Nothing (Just filter)
      myTweet <- searchTweet search
      liftIO $
        myTweet `shouldBe` Right exampleTweet

    it "doesn't return document for non-matching regexp filter" $ withTestEnv $ do
      _ <- insertData
      let filter = RegexpFilter (FieldName "user")
                   (Regexp "boy") AllRegexpFlags
                   (CacheName "test") False (CacheKey "key")
      let search = mkSearch Nothing (Just filter)
      searchExpectNoResults search

  describe "Aggregation API" $ do
    it "returns term aggregation results" $ withTestEnv $ do
      _ <- insertData
      let terms = TermsAgg $ mkTermsAggregation "user"
      let search = mkAggregateSearch Nothing $ mkAggregations "users" terms
      searchExpectAggs search
      searchValidBucketAgg search "users" toTerms

    it "can give collection hint parameters to term aggregations" $ when' (atleast es13) $ withTestEnv $ do
      _ <- insertData
      let terms = TermsAgg $ (mkTermsAggregation "user") { termCollectMode = Just BreadthFirst }
      let search = mkAggregateSearch Nothing $ mkAggregations "users" terms
      searchExpectAggs search
      searchValidBucketAgg search "users" toTerms

    it "can give execution hint paramters to term aggregations" $ when' (atmost es11) $ withTestEnv $ do
      _ <- insertData
      searchTermsAggHint [Map, Ordinals]

    it "can give execution hint paramters to term aggregations" $ when' (is es12) $ withTestEnv $ do
      _ <- insertData
      searchTermsAggHint [GlobalOrdinals, GlobalOrdinalsHash, GlobalOrdinalsLowCardinality, Map, Ordinals]

    it "can give execution hint paramters to term aggregations" $ when' (atleast es12) $ withTestEnv $ do
      _ <- insertData
      searchTermsAggHint [GlobalOrdinals, GlobalOrdinalsHash, GlobalOrdinalsLowCardinality, Map]

    it "returns date histogram aggregation results" $ withTestEnv $ do
      _ <- insertData
      let histogram = DateHistogramAgg $ mkDateHistogram (FieldName "postDate") Minute
      let search = mkAggregateSearch Nothing (mkAggregations "byDate" histogram)
      searchExpectAggs search
      searchValidBucketAgg search "byDate" toDateHistogram

    it "returns date histogram using fractional date" $ withTestEnv $ do
      _ <- insertData
      let periods            = [Year, Quarter, Month, Week, Day, Hour, Minute, Second]
      let fractionals        = map (FractionalInterval 1.5) [Weeks, Days, Hours, Minutes, Seconds]
      let intervals          = periods ++ fractionals
      let histogram          = mkDateHistogram (FieldName "postDate")
      let search interval    = mkAggregateSearch Nothing $ mkAggregations "byDate" $ DateHistogramAgg (histogram interval)
      let expect interval    = searchExpectAggs (search interval)
      let valid interval     = searchValidBucketAgg (search interval) "byDate" toDateHistogram
      forM_ intervals expect
      forM_ intervals valid

  describe "Highlights API" $ do

    it "returns highlight from query when there should be one" $ withTestEnv $ do
      _ <- insertData
      _ <- insertOther
      let query = QueryMatchQuery $ mkMatchQuery (FieldName "_all") (QueryString "haskell")
      let testHighlight = Highlights Nothing [FieldHighlight (FieldName "message") Nothing]

      let search = mkHighlightSearch (Just query) testHighlight
      myHighlight <- searchTweetHighlight search
      liftIO $
        myHighlight `shouldBe` Right (Just (M.fromList [("message",["Use <em>haskell</em>!"])]))

    it "doesn't return highlight from a query when it shouldn't" $ withTestEnv $ do
      _ <- insertData
      _ <- insertOther
      let query = QueryMatchQuery $ mkMatchQuery (FieldName "_all") (QueryString "haskell")
      let testHighlight = Highlights Nothing [FieldHighlight (FieldName "user") Nothing]

      let search = mkHighlightSearch (Just query) testHighlight
      myHighlight <- searchTweetHighlight search
      liftIO $
        myHighlight `shouldBe` Right Nothing



  describe "ToJSON RegexpFlags" $ do
    it "generates the correct JSON for AllRegexpFlags" $
      toJSON AllRegexpFlags `shouldBe` String "ALL"

    it "generates the correct JSON for NoRegexpFlags" $
      toJSON NoRegexpFlags `shouldBe` String "NONE"

    it "generates the correct JSON for SomeRegexpFlags" $
      let flags = AnyString :| [ Automaton
                               , Complement
                               , Empty
                               , Intersection
                               , Interval ]
      in toJSON (SomeRegexpFlags flags) `shouldBe` String "ANYSTRING|AUTOMATON|COMPLEMENT|EMPTY|INTERSECTION|INTERVAL"

    prop "removes duplicates from flags" $ \(flags :: RegexpFlags) ->
      let String str = toJSON flags
          flagStrs   = T.splitOn "|" str
      in noDuplicates flagStrs

  describe "omitNulls" $ do
    it "checks that omitNulls drops list elements when it should" $
       let dropped = omitNulls $ [ "test1" .= (toJSON ([] :: [Int]))
                                 , "test2" .= (toJSON ("some value" :: Text))]
       in dropped `shouldBe` Object (HM.fromList [("test2", String "some value")])

    it "checks that omitNulls doesn't drop list elements when it shouldn't" $
       let notDropped = omitNulls $ [ "test1" .= (toJSON ([1] :: [Int]))
                                    , "test2" .= (toJSON ("some value" :: Text))]
       in notDropped `shouldBe` Object (HM.fromList [ ("test1", Array (V.fromList [Number 1.0]))
                                                 , ("test2", String "some value")])
    it "checks that omitNulls drops non list elements when it should" $
       let dropped = omitNulls $ [ "test1" .= (toJSON Null)
                                 , "test2" .= (toJSON ("some value" :: Text))]
       in dropped `shouldBe` Object (HM.fromList [("test2", String "some value")])
    it "checks that omitNulls doesn't drop non list elements when it shouldn't" $
       let notDropped = omitNulls $ [ "test1" .= (toJSON (1 :: Int))
                                    , "test2" .= (toJSON ("some value" :: Text))]
       in notDropped `shouldBe` Object (HM.fromList [ ("test1", Number 1.0)
                                                   , ("test2", String "some value")])
  describe "Monoid (SearchHits a)" $ do
    prop "abides the monoid laws" $ eq $
      prop_Monoid (T :: T (SearchHits ()))