diff --git a/hpgsql-tests/LibPqConnStringParsingSpec.hs b/hpgsql-tests/LibPqConnStringParsingSpec.hs
new file mode 100644
index 0000000..e5b7945
--- /dev/null
+++ b/hpgsql-tests/LibPqConnStringParsingSpec.hs
@@ -0,0 +1,389 @@
+module LibPqConnStringParsingSpec
+  ( spec,
+  )
+where
+
+import Control.Monad (forM_)
+import qualified Data.Char as Char
+import Data.Hashable (Hashable, hash)
+import Data.List (sortOn)
+import Data.Maybe (catMaybes)
+import Data.Text (Text)
+import qualified Data.Text as Text
+import Data.Text.Encoding (decodeUtf8)
+import Data.Word (Word16)
+import Hedgehog (Gen, forAll, (===))
+import qualified Hedgehog.Gen as Gen
+import qualified Hedgehog.Range as Range
+import Hpgsql.Connection (ConnectionString (..), parseLibpqConnectionString, renderLibpqConnectionString)
+import Network.URI
+  ( URI (..),
+    URIAuth (..),
+    escapeURIString,
+    isUnescapedInURIComponent,
+    uriToString,
+  )
+import Test.Hspec
+import Test.Hspec.Hedgehog (hedgehog)
+
+-- This test suite was copied over from my other project, codd, and changed to use
+-- hedgehog instead of quickcheck, plus a few tests removed because they didn't make sense here.
+-- It would be nice to produce "options" fields for the connection strings too, these tests still
+-- produce them as empty.
+
+spec :: Spec
+spec = do
+  describe "Connection string parsing" $ do
+    it "Some hard coded connection strings" $ do
+      -- These are hard coded connection strings that I've tested with psql at some point
+      let stringsAndExpectedConnInfos =
+            [ ( "postgresql://postgres@localhost/some%20thing%20%2F%3F%3A%40",
+                ConnectionString
+                  { hostname = "localhost",
+                    port = 5432,
+                    user = "postgres",
+                    password = "",
+                    database = "some thing /?:@",
+                    options = ""
+                  }
+              ),
+              ( "postgresql://some%20thing%20%2F%3F%3A%40:passwdsome%20thing%20%2F%3F%3A%40@localhost:1/some%20thing%20%2F%3F%3A%40",
+                ConnectionString
+                  { hostname = "localhost",
+                    port = 1,
+                    user = "some thing /?:@",
+                    password = "passwdsome thing /?:@",
+                    database = "some thing /?:@",
+                    options = ""
+                  }
+              ),
+              -- Only mandatory arguments
+              ( "postgresql://postgres@[::1]/somedb",
+                ConnectionString
+                  { hostname = "::1",
+                    port = 5432,
+                    user = "postgres",
+                    password = "",
+                    database = "somedb",
+                    options = ""
+                  }
+              ),
+              ( "dbname='some thing /?:@' user='some thing /?:@'   host = localhost   ",
+                ConnectionString
+                  { hostname = "localhost",
+                    port = 5432,
+                    user = "some thing /?:@",
+                    password = "",
+                    database = "some thing /?:@",
+                    options = ""
+                  }
+              ),
+              ( "dbname='some thing /?:@'\nuser='some thing /?:@' password='passwdsome thing /?:@' port=1 host = localhost\n",
+                ConnectionString
+                  { hostname = "localhost",
+                    port = 1,
+                    user = "some thing /?:@",
+                    password = "passwdsome thing /?:@",
+                    database = "some thing /?:@",
+                    options = ""
+                  }
+              ),
+              ( "\ndbname=codd-experiments   \t\n    user=postgres port=5433 host=::1\n",
+                ConnectionString
+                  { hostname = "::1",
+                    port = 5433,
+                    user = "postgres",
+                    password = "",
+                    database = "codd-experiments",
+                    options = ""
+                  }
+              ),
+              -- Only mandatory arguments
+              ( "dbname=codd-experiments\tuser=postgres\rhost=127.0.0.1",
+                ConnectionString
+                  { hostname = "127.0.0.1",
+                    port = 5432,
+                    user = "postgres",
+                    password = "",
+                    database = "codd-experiments",
+                    options = ""
+                  }
+              ),
+              -- I didn't really test this with psql, but IIUC = signs should be accepted as parts of values
+              ( "dbname=codd-experiments\t  user=  post=gres password='abc = def'  host=127.0.0.1",
+                ConnectionString
+                  { hostname = "127.0.0.1",
+                    port = 5432,
+                    user = "post=gres",
+                    password = "abc = def",
+                    database = "codd-experiments",
+                    options = ""
+                  }
+              )
+            ]
+      forM_ stringsAndExpectedConnInfos $ \(connString, expectedConnInfo) -> do
+        parseLibpqConnectionString
+          connString
+          `shouldBe` Right expectedConnInfo
+
+    it "Randomized valid connection strings" $ hedgehog $ do
+      connGen <- forAll genConnStringGen
+      let expectedConn = connInfoFromConnStringGen connGen
+      parseLibpqConnectionString (renderConnStringGen connGen) === Right expectedConn
+      -- Round-tripping with `renderLibpqConnectionString`
+      parseLibpqConnectionString (decodeUtf8 $ renderLibpqConnectionString expectedConn) === Right expectedConn
+
+newtype ObjName = ObjName {unObjName :: Text}
+  deriving newtype (Eq, Ord, Show, Hashable)
+
+validLowerFirstChars :: [Char]
+validLowerFirstChars = '_' : ['a' .. 'z']
+
+validUpperFirstChars :: [Char]
+validUpperFirstChars = ['A' .. 'Z']
+
+genObjName :: Gen ObjName
+genObjName =
+  ObjName . Text.pack
+    <$> Gen.frequency
+      [(100, genLower), (5, genMixed)]
+  where
+    validLowerOtherChars = validLowerFirstChars ++ "0123456789$"
+    validUpperOtherChars = validUpperFirstChars ++ "0123456789$"
+
+    genLower = do
+      c <- Gen.element validLowerFirstChars
+      -- Max Length 63 bytes of UTF8-Encoded name
+      r <- Gen.list (Range.linear 0 62) $ Gen.element validLowerOtherChars
+      pure $ c : r
+    genMixed = do
+      c <- Gen.element $ validLowerFirstChars ++ validUpperFirstChars
+      -- Max Length 63 bytes of UTF8-Encoded name
+      r <-
+        Gen.list (Range.linear 0 62) $
+          Gen.element $
+            validLowerOtherChars
+              ++ validUpperOtherChars
+      pure $ c : r
+
+data HostString = Hostname Text | HostUnixSocket Text
+  deriving stock (Show)
+
+originalHost :: HostString -> Text
+originalHost (Hostname t) = t
+originalHost (HostUnixSocket t) = t
+
+genHostString :: Gen HostString
+genHostString =
+  Gen.element
+    [ Hostname "127.0.0.1",
+      Hostname "200.200.100.100",
+      Hostname "hostnodots",
+      Hostname "some.host.name",
+      Hostname "::1",
+      Hostname "2800:3f0:4001:822::200e",
+      Hostname "2a03:2880:f105:283:face:b00c:0:25de",
+      HostUnixSocket "/var/lib/postgresql"
+    ]
+
+data ConnStringType = URIpostgres | Kwvps
+  deriving stock (Bounded, Enum, Show)
+
+getURIConnString ::
+  Text -> ObjName -> Text -> HostString -> Word16 -> ObjName -> Text
+getURIConnString (Text.unpack -> uriScheme) (Text.unpack . unObjName -> usr) (Text.unpack -> pwd) host port (Text.unpack . unObjName -> dbName) =
+  Text.pack $ uriToString id uri ""
+  where
+    uri =
+      URI
+        { uriScheme,
+          uriAuthority =
+            Just
+              URIAuth
+                { uriUserInfo =
+                    encodeURIComponent usr
+                      <> ( if pwd == ""
+                             then ""
+                             else ':' : encodeURIComponent pwd
+                         )
+                      <> "@",
+                  uriRegName = Text.unpack $ escapeHost host,
+                  uriPort = ':' : show port
+                },
+          uriPath = '/' : encodeURIComponent dbName,
+          uriQuery = "",
+          uriFragment = ""
+        }
+
+encodeURIComponent :: String -> String
+encodeURIComponent = escapeURIString isUnescapedInURIComponent
+
+data KwvpConnGen = KwvpConnGen
+  { -- | Shuffles the relative order of keyword/value pairs in the generated connection string.
+    shuffleIdx :: Int,
+    -- | The boolean dictates quoting when quoting is optional.
+    -- The Int represents extra spaces around this kwvp. These will be added one by one
+    -- left-to-right everywhere they are acceptable until a limit of 4 (therefore ignoring > 4 spaces).
+    user :: (ObjName, Bool, Int),
+    kwvp_password :: Maybe (Text, Bool, Int),
+    host :: (HostString, Bool, Int),
+    kwvp_port :: Maybe (Word16, Bool, Int),
+    dbname :: (ObjName, Bool, Int)
+  }
+  deriving stock (Show)
+
+getKeywordValuePairConnString :: KwvpConnGen -> Text
+getKeywordValuePairConnString KwvpConnGen {..} =
+  Text.intercalate " " $
+    map (\(kw, v) -> kw <> "=" <> v) mixedKwvps
+  where
+    mixedKwvps =
+      sortOn ((`mod` max 1 shuffleIdx) . hash) $
+        catMaybes
+          [ Just $ addExtraSpaces user ("user", quoteIfNeeded unObjName user),
+            Just $
+              addExtraSpaces
+                host
+                ("host", quoteIfNeeded originalHost host),
+            Just $
+              addExtraSpaces dbname ("dbname", quoteIfNeeded unObjName dbname),
+            (\p -> addExtraSpaces p ("password", quoteIfNeeded id p))
+              <$> kwvp_password,
+            (\p -> addExtraSpaces p ("port", quoteIfNeeded (Text.pack . show) p))
+              <$> kwvp_port
+          ]
+    addExtraSpaces (_, _, spaces) (k, v)
+      | spaces <= 0 = (k, v)
+      | spaces == 1 = (" " <> k, v)
+      | spaces == 2 = (" " <> k <> " ", v)
+      | spaces == 3 = (" " <> k <> " ", " " <> v)
+      | otherwise = (" " <> k <> " ", " " <> v <> " ")
+    quoteIfNeeded un (v, force, _) =
+      if needsQuoting (un v) || force
+        then
+          "'"
+            <> Text.replace "'" "\\'" (Text.replace "\\" "\\\\" (un v))
+            <> "'"
+        else un v
+    needsQuoting v =
+      "'"
+        `Text.isInfixOf` v
+        || "\\"
+          `Text.isInfixOf` v
+        || Text.any Char.isSpace v
+        || v
+          == ""
+
+escapeHost :: HostString -> Text
+escapeHost (Hostname host) =
+  -- bracket-escape IPv6 addresses
+  if ":" `Text.isInfixOf` host then "[" <> host <> "]" else host
+escapeHost (HostUnixSocket socketpath) = Text.pack $ encodeURIComponent $ Text.unpack socketpath
+
+newtype ConnStringGen = ConnStringGen (Either KwvpConnGen (Text, ObjName, Text, HostString, Word16, ObjName))
+
+instance Show ConnStringGen where
+  show (ConnStringGen kwvpOrUriScheme) = Text.unpack $
+    case kwvpOrUriScheme of
+      Left kwvpConnGen -> getKeywordValuePairConnString kwvpConnGen
+      Right (uriScheme, usr, pwd, host, port, dbName) ->
+        getURIConnString uriScheme usr pwd host port dbName
+
+renderConnStringGen :: ConnStringGen -> Text
+renderConnStringGen (ConnStringGen kwvpOrUriScheme) =
+  case kwvpOrUriScheme of
+    Left kwvpConnGen -> getKeywordValuePairConnString kwvpConnGen
+    Right (uriScheme, usr, pwd, host, port, dbName) ->
+      getURIConnString uriScheme usr pwd host port dbName
+
+connInfoFromConnStringGen :: ConnStringGen -> ConnectionString
+connInfoFromConnStringGen (ConnStringGen kwvpOrUriScheme) =
+  case kwvpOrUriScheme of
+    Left KwvpConnGen {user = (user, _, _), host = (host, _, _), dbname = (dbname, _, _), kwvp_password, kwvp_port} ->
+      ConnectionString
+        { hostname = originalHost host,
+          port = case kwvp_port of
+            Nothing -> 5432
+            Just (p, _, _) -> p,
+          user = unObjName user,
+          password = case kwvp_password of
+            Nothing -> ""
+            Just (p, _, _) -> p,
+          database = unObjName dbname,
+          options = ""
+        }
+    Right (_uriScheme, user, password, host, port, dbname) ->
+      ConnectionString
+        { hostname = originalHost host,
+          port = port,
+          user = unObjName user,
+          password = password,
+          database = unObjName dbname,
+          options = ""
+        }
+
+genConnStringGen :: Gen ConnStringGen
+genConnStringGen = do
+  usr <- genObjName
+  pwd <-
+    Gen.choice
+      [ pure "",
+        Gen.list (Range.linear 0 100) (Gen.element [' ' .. '~'])
+      ]
+  host <- genHostString
+  port <- Gen.choice [pure 5432, Gen.word16 Range.linearBounded]
+  dbName <- genObjName
+
+  let connInfo =
+        ConnectionString
+          { hostname = originalHost host,
+            port,
+            user = unObjName usr,
+            password = Text.pack pwd,
+            database = unObjName dbName,
+            options = ""
+          }
+  connStringType <- Gen.enumBounded @_ @ConnStringType
+  case connStringType of
+    Kwvps -> do
+      shuffleIdx <- Gen.int Range.linearBounded
+      b1 <- Gen.bool
+      s1 <- Gen.int Range.linearBounded
+      b2 <- Gen.bool
+      s2 <- Gen.int Range.linearBounded
+      b3 <- Gen.bool
+      s3 <- Gen.int Range.linearBounded
+      b4 <- Gen.bool
+      s4 <- Gen.int Range.linearBounded
+      b5 <- Gen.bool
+      s5 <- Gen.int Range.linearBounded
+      withPwd <-
+        if connInfo.password == ""
+          then Gen.bool
+          else pure True
+      withPort <-
+        if port == 5432
+          then Gen.bool
+          else pure True
+      pure $
+        ConnStringGen $
+          Left $
+            KwvpConnGen
+              { shuffleIdx,
+                user = (usr, b1, s1),
+                kwvp_password =
+                  if withPwd
+                    then Just (Text.pack pwd, b2, s2)
+                    else Nothing,
+                host = (host, b3, s3),
+                kwvp_port =
+                  if withPort
+                    then Just (port, b4, s4)
+                    else Nothing,
+                dbname = (dbName, b5, s5)
+              }
+    URIpostgres -> do
+      uriScheme <- Gen.element ["postgres:", "postgresql:"]
+      pure $
+        ConnStringGen $
+          Right (uriScheme, usr, Text.pack pwd, host, port, dbName)
diff --git a/hpgsql-tests/hpgsql-tests.cabal b/hpgsql-tests/hpgsql-tests.cabal
index 8b13ea3..4a16b6b 100644
--- a/hpgsql-tests/hpgsql-tests.cabal
+++ b/hpgsql-tests/hpgsql-tests.cabal
@@ -31,6 +31,7 @@ executable hpgsql-tests
       DbUtils
       DocumentationExamplesSpec
       EncodingDecodingSpec
+      LibPqConnStringParsingSpec
       NotificationsSpec
       ParsingSpec
       PipelineSpec
@@ -84,10 +85,12 @@ executable hpgsql-tests
     , bytestring
     , case-insensitive
     , containers
+    , hashable
     , hedgehog
     , hpgsql
     , hspec
     , hspec-hedgehog
+    , network-uri
     , postgresql-simple
     , random
     , safe-exceptions