pyrites/haskell-experiments/test/Test/SimpleParserSpec.hs

{-# LANGUAGE DuplicateRecordFields #-}
{-# LANGUAGE OverloadedRecordDot #-}
{-# HLINT ignore "Use const" #-}
{-# HLINT ignore "Unused LANGUAGE pragma" #-}
{-# HLINT ignore "Avoid lambda" #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE NoFieldSelectors #-}
{-# OPTIONS_GHC -Wno-unrecognised-pragmas #-}
{-# LANGUAGE TypeApplications #-}

module Test.SimpleParserSpec where

import Test.Hspec
import Text.Megaparsec
import SimpleParser

spec :: Spec
spec = do
  describe "evaluate expressions" $ do
    it "arithmetic on literals" $ do
      eval (BinaryExpr Add (Literal 2) (Literal 3) ) `shouldBe` 5
      eval (BinaryExpr Subtract (Literal 2) (Literal 3) ) `shouldBe` -1
      eval (BinaryExpr Multiply (Literal 2) (Literal 3) ) `shouldBe` 6
      eval (BinaryExpr Divide (Literal 7) (Literal 3) ) `shouldBe` 2
      eval (UnaryExpr Negate (Literal 7) ) `shouldBe` -7
    it "more complex arithmetic on literals" $ do
      eval (BinaryExpr Add 
        (UnaryExpr Negate (Literal 1)) 
        (BinaryExpr Divide (Literal 7) (Literal 3))
        ) `shouldBe` 1
    it "can parse basic expressions" $ do
      parse parseExpr "" "2" `shouldBe` Right (Literal 2)
      parse parseExpr "" "2+3" `shouldBe` Right (BinaryExpr Add (Literal 2) (Literal 3))