[Login] simplify condition for useEffect

src/Gargantext/Components/Login.purs

@@ -110,7 +110,7 @@ renderCpt d s = R.createElement el {} []
       (state /\ setState) <- R.useState' s
 
       R.useEffect $
-        if (state.username /= s.username && state.password /= s.password) then do
+        if (state /= s) then do
           _ <- d $ SetCredentials state.username state.password
           pure $ d $ PostAuth
         else

src/Gargantext/Components/Login/Types.purs

 module Gargantext.Components.Login.Types where
 
 import Prelude
-import Data.Lens (Iso', iso)
 import Data.Argonaut ( class DecodeJson, class EncodeJson, decodeJson, jsonEmptyObject
-                     , (.?), (.??), (:=), (~>)
-                     )
+                      , (.?), (.??), (:=), (~>)
+                      )
+import Data.Generic.Rep (class Generic)
+import Data.Generic.Rep.Eq (genericEq)
+import Data.Lens (Iso', iso)
 import Data.Maybe (Maybe)
 
 type Username = String
@@ -30,6 +32,12 @@ newtype AuthData = AuthData
   , tree_id :: TreeId
   }
 
+
+derive instance genericAuthData :: Generic AuthData _
+
+instance eqAuthData :: Eq AuthData where
+  eq = genericEq
+
 _AuthData :: Iso' AuthData { token :: Token, tree_id :: TreeId }
 _AuthData = iso (\(AuthData v) -> v) AuthData