module Nuthatch.Probe.Assert
  ( assert
  , assertContains
  , assertEqual
  , requireEnv
  ) where

import           Control.Monad (unless)
import qualified Data.ByteString as BS
import           System.Environment (lookupEnv)

assert :: String -> Bool -> IO ()
assert label condition =
  unless condition (fail label)

assertContains :: String -> BS.ByteString -> BS.ByteString -> IO ()
assertContains label needle haystack =
  assert label (needle `BS.isInfixOf` haystack)

assertEqual :: (Eq value, Show value) => String -> value -> value -> IO ()
assertEqual label expected actual =
  unless (actual == expected) $
    fail (label <> ": expected " <> show expected <> ", got " <> show actual)

requireEnv :: String -> IO String
requireEnv name =
  lookupEnv name >>= maybe (fail ("missing " <> name)) pure