MoneySpec.hs

module PostgresqlTypes.MoneySpec (spec) where

import qualified Data.Attoparsec.Text
import Data.Data (Proxy (Proxy))
import Data.Int
import qualified PostgresqlTypes.Algebra
import qualified PostgresqlTypes.Money as Money
import Test.Hspec
import Test.QuickCheck
import qualified TextBuilder
import qualified UnitTests.Scripts as Scripts
import Prelude

spec :: Spec
spec = do
  describe "Show/Read laws" do
    Scripts.testShowRead (Proxy @Money.Money)

  describe "IsScalar laws" do
    Scripts.testIsScalar (Proxy @Money.Money)

  describe "Constructors" do
    describe "fromInt64" do
      it "creates Money from positive Int64" do
        let pgMoney = Money.fromInt64 12345
        Money.toInt64 pgMoney `shouldBe` 12345

      it "creates Money from negative Int64" do
        let pgMoney = Money.fromInt64 (-12345)
        Money.toInt64 pgMoney `shouldBe` (-12345)

      it "creates Money from zero" do
        let pgMoney = Money.fromInt64 0
        Money.toInt64 pgMoney `shouldBe` 0

  describe "Accessors" do
    describe "toInt64" do
      it "extracts Int64 value representing cents" do
        let pgMoney = Money.fromInt64 9999
        Money.toInt64 pgMoney `shouldBe` 9999

  describe "Edge Cases" do
    it "textual encoder handles minBound @Int64 correctly" do
      let pgMoney = Money.fromInt64 (minBound @Int64)
          encoded = TextBuilder.toText (PostgresqlTypes.Algebra.textualEncoder pgMoney)
          decoded = Data.Attoparsec.Text.parseOnly (PostgresqlTypes.Algebra.textualDecoder @Money.Money) encoded
      decoded `shouldBe` Right pgMoney

    it "textual encoder handles maxBound @Int64 correctly" do
      let pgMoney = Money.fromInt64 (maxBound @Int64)
          encoded = TextBuilder.toText (PostgresqlTypes.Algebra.textualEncoder pgMoney)
          decoded = Data.Attoparsec.Text.parseOnly (PostgresqlTypes.Algebra.textualDecoder @Money.Money) encoded
      decoded `shouldBe` Right pgMoney

  describe "Property Tests" do
    it "roundtrips through toInt64 and fromInt64" do
      property \(i :: Int64) ->
        let pgMoney = Money.fromInt64 i
         in Money.toInt64 pgMoney === i

    it "roundtrips through fromInt64 and toInt64" do
      property \(pgMoney :: Money.Money) ->
        let i = Money.toInt64 pgMoney
            pgMoney' = Money.fromInt64 i
         in pgMoney' === pgMoney