expected project balance

epb.hs

    (old_shares, old_share_value, expected_share_value) <- testDB $ do
        old_project_shares <- fetchProjectSharesDB project_id
        old_user_shares    <- getBy (UniquePledge user_id project_id) >>= \case
            Nothing -> return 0
            Just p  -> return $ pledgeFundedShares $ entityVal p
        return ( old_user_shares
               , projectComputeShareValue old_project_shares
               , projectComputeShareValue $
                     shares : delete old_user_shares old_project_shares )

    let expected_project_balance =
            accountBalance project_account
            - (old_shares *$ old_share_value)
            + (shares *$ expected_share_value)