CharSpec.hs

module PostgresqlTypes.CharSpec (spec) where

import Data.Data (Proxy (Proxy))
import Data.Maybe
import Data.Word
import qualified PostgresqlTypes.Char as PgChar
import Test.Hspec
import Test.QuickCheck
import qualified UnitTests.Scripts as Scripts
import Prelude hiding (Char)

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

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

  describe "Constructors" do
    describe "normalizeFromWord8" do
      it "creates Char from ASCII byte" do
        let pgChar = PgChar.normalizeFromWord8 65 -- 'A'
        PgChar.toWord8 pgChar `shouldBe` 65

      it "clears bit 7 for values above 127" do
        let pgChar = PgChar.normalizeFromWord8 200 -- Binary: 11001000
        PgChar.toWord8 pgChar `shouldBe` 72 -- Binary: 01001000 (bit 7 cleared)
    describe "refineFromWord8" do
      it "accepts ASCII values (0-127)" do
        let result = PgChar.refineFromWord8 65
        result `shouldSatisfy` isJust
        fmap PgChar.toWord8 result `shouldBe` Just 65

      it "rejects values above 127" do
        PgChar.refineFromWord8 128 `shouldBe` Nothing
        PgChar.refineFromWord8 255 `shouldBe` Nothing

    describe "normalizeFromChar" do
      it "creates Char from Haskell Char" do
        let pgChar = PgChar.normalizeFromChar 'A'
        PgChar.toChar pgChar `shouldBe` 'A'

    describe "refineFromChar" do
      it "accepts ASCII characters" do
        let result = PgChar.refineFromChar 'Z'
        result `shouldSatisfy` isJust

  describe "Accessors" do
    describe "toWord8" do
      it "extracts Word8 value" do
        let pgChar = PgChar.normalizeFromWord8 42
        PgChar.toWord8 pgChar `shouldBe` 42

    describe "toChar" do
      it "extracts Haskell Char" do
        let pgChar = PgChar.normalizeFromChar 'B'
        PgChar.toChar pgChar `shouldBe` 'B'

  describe "Property Tests" do
    it "roundtrips through toWord8 and normalizeFromWord8 for valid ASCII" do
      property \(w :: Word8) ->
        w <= 127 ==>
          let pgChar = PgChar.normalizeFromWord8 w
           in PgChar.toWord8 pgChar === w

    it "roundtrips through normalizeFromWord8 and toWord8" do
      property \(pgChar :: PgChar.Char) ->
        let w = PgChar.toWord8 pgChar
            pgChar' = PgChar.normalizeFromWord8 w
         in pgChar' === pgChar