ghc-plugin-non-empty-0.0.0.0: test/Spec.hs

{-# LANGUAGE BangPatterns #-}

module Main (main) where

import Control.Exception (ErrorCall, TypeError)
import Data.List.NonEmpty (NonEmpty (..))
import Test.Hspec (describe, hspec, it, shouldBe, shouldThrow)

import Test.Data.Fail as Test
import Test.Data.Overloaded as Test
import Test.Data.Plain as Test


main :: IO ()
main = hspec $ describe "GhcPluginNonEmpty.plugin" $ do
    describe "Plain" $ do
        it "doesn't change ordinary empty list" $
            Test.emptyList `shouldBe` []
        it "doesn't change ordinary non-empty list" $
            Test.listInt `shouldBe` [3, 1, 2]
        it "correctly converts to non-empty int list" $
            Test.nonEmptyListInt `shouldBe` 5 :| [10, 7]
        it "correctly converts to non-empty bool list" $
            Test.nonEmptyListBool `shouldBe` True :| [False]
        it "correctly converts singleton non-empty int list" $
            Test.nonEmptyListSingleton `shouldBe` 42 :| []
        it "doesn't change explicit non-empty lists" $
            Test.nonEmptyListExplicit `shouldBe` 42 :| [50, 100]

    describe "Fail" $
        it "compiler error on trying to convert empty list to non-empty" $ do
            let action = let !x = Test.emptyNonEmpty in pure x
            action `shouldThrow` \(_ :: TypeError) -> True

    describe "Overloaded" $ do
        it "doesn't change overloaded ordinary empty list" $
            Test.overloadedListEmpty `shouldBe` []
        it "doesn't change overloaded ordinary non-empty list" $
            Test.overloadedListInt `shouldBe` [3, 1, 2]
        it "converts overloaded NonEmpty list" $
            Test.overloadedNonEmptyInt `shouldBe` 15 :| [6, 7]
        it "runtime error on trying to convert empty list to non-empty" $ do
            let action = let !x = Test.overloadedEmptyNonEmpty in pure x
            action `shouldThrow` \(_ :: ErrorCall) -> True