Add support for bigint (#5)

* Add support for bigint

Add multiple deserialisation options

* Add npm install

.github/workflows/ci.yml

@@ -31,7 +31,7 @@ jobs:
           path: |
             .spago
             output
-
+      - run: npm install
       - run: spago build
 
       - run: spago -x test.dhall test

package-lock.json

@@ -0,0 +1,27 @@
+{
+  "name": "purescript-yoga-json",
+  "lockfileVersion": 2,
+  "requires": true,
+  "packages": {
+    "": {
+      "dependencies": {
+        "big-integer": "^1.6.51"
+      }
+    },
+    "node_modules/big-integer": {
+      "version": "1.6.51",
+      "resolved": "https://registry.npmjs.org/big-integer/-/big-integer-1.6.51.tgz",
+      "integrity": "sha512-GPEid2Y9QU1Exl1rpO9B2IPJGHPSupF5GnVIP0blYvNOMer2bTvSWs1jGOUg04hTmu67nmLsQ9TBo1puaotBHg==",
+      "engines": {
+        "node": ">=0.6"
+      }
+    }
+  },
+  "dependencies": {
+    "big-integer": {
+      "version": "1.6.51",
+      "resolved": "https://registry.npmjs.org/big-integer/-/big-integer-1.6.51.tgz",
+      "integrity": "sha512-GPEid2Y9QU1Exl1rpO9B2IPJGHPSupF5GnVIP0blYvNOMer2bTvSWs1jGOUg04hTmu67nmLsQ9TBo1puaotBHg=="
+    }
+  }
+}

package.json

@@ -0,0 +1,6 @@
+{
+  "dependencies": {
+    "big-integer": "^1.6.51"
+  },
+  "type": "module"
+}

spago.dhall

@@ -4,6 +4,8 @@
 , dependencies =
   [ "arrays"
   , "bifunctors"
+  , "bigints"
+  , "console"
   , "control"
   , "effect"
   , "either"

src/Yoga/JSON.js

@@ -1,5 +1,18 @@
-export const _parseJSON = JSON.parse;
+function reviver(key, value) {
+    if (key === 'big') {
+        return BigInt(value);
+    }
+    return value;
+}
+export const _parseJSON = (payload) => JSON.parse(payload, reviver);
 
 export const _undefined = undefined;
 
-export const _unsafeStringify = JSON.stringify;
+function replacer(key, value) {
+    if (key === 'big') {
+      return value.toString();
+    }
+    return value;
+  }
+  
+export const _unsafeStringify = (data) => JSON.stringify(data, replacer);

src/Yoga/JSON.purs

@@ -39,11 +39,13 @@ import Control.Monad.Except (ExceptT(..), except, runExcept, throwError, withExc
 import Data.Array as Array
 import Data.Array.NonEmpty (NonEmptyArray, fromArray, toArray)
 import Data.Bifunctor (lmap)
+import Data.BigInt (BigInt)
+import Data.BigInt as BigInt
 import Data.Either (Either, hush, note)
 import Data.FoldableWithIndex (foldrWithIndex)
 import Data.Identity (Identity(..))
 import Data.Int as Int
-import Data.List.NonEmpty (singleton)
+import Data.List.NonEmpty (NonEmptyList, singleton)
 import Data.Map (Map)
 import Data.Map as Map
 import Data.Maybe (Maybe(..), fromMaybe, fromMaybe', maybe)
@@ -57,7 +59,7 @@ import Data.Variant (Variant, inj, on)
 import Effect.Exception (message, try)
 import Effect.Uncurried as EU
 import Effect.Unsafe (unsafePerformEffect)
-import Foreign (F, Foreign, ForeignError(..), MultipleErrors, fail, isNull, isUndefined, readArray, readBoolean, readChar, readInt, readNull, readNumber, readString, tagOf, unsafeFromForeign, unsafeToForeign)
+import Foreign (F, Foreign, ForeignError(..), MultipleErrors, fail, isNull, isUndefined, readArray, readBoolean, readChar, readInt, readNull, readNumber, readString, tagOf, unsafeFromForeign, unsafeReadTagged, unsafeToForeign)
 import Foreign.Index (readProp)
 import Foreign.Object (Object)
 import Foreign.Object as Object
@@ -177,6 +179,24 @@ instance ReadForeign Number where
 instance ReadForeign Int where
   readImpl = readInt
 
+-- | Attempt to coerce a foreign value to a `BigInt`.
+readBigInt ∷
+  ∀ m. Monad m ⇒ Foreign → ExceptT (NonEmptyList ForeignError) m BigInt
+readBigInt = unsafeReadTagged "BigInt"
+
+instance ReadForeign BigInt where
+  readImpl fValue = tryInt fValue <|> readBigInt fValue <|> tryString fValue
+    where
+    tryInt f = readInt f <#> BigInt.fromInt
+    tryString f = do
+      bi ← readString f
+      BigInt.fromString bi
+        # note
+            ( singleton $ ForeignError $ "String " <> bi <>
+                " could not be converted to BigInt"
+            )
+        # except
+        
 instance ReadForeign String where
   readImpl = readString
 
@@ -351,6 +371,9 @@ instance WriteForeign Char where
 instance WriteForeign Number where
   writeImpl = unsafeToForeign
 
+instance WriteForeign BigInt where
+  writeImpl = unsafeToForeign
+
 instance WriteForeign Boolean where
   writeImpl = unsafeToForeign
 
@@ -484,4 +507,4 @@ instance (Newtype nt key, ReadForeign (Map key value)) => ReadForeign (Map nt va
 
 unsafeStringToInt :: String → Int
 unsafeStringToInt = Int.fromString >>>
-  (fromMaybe' \_ -> unsafeCrashWith "impossible")
+  (fromMaybe' \_ -> unsafeCrashWith "impossible")

test/BasicsSpec.purs

@@ -3,6 +3,7 @@ module Test.BasicsSpec where
 import Prelude
 
 import Data.Array.NonEmpty as NEA
+import Data.BigInt (BigInt)
 import Data.Either (Either(..))
 import Data.Foldable (traverse_)
 import Data.List as List
@@ -51,7 +52,26 @@ spec = describe "En- and decoding" $ do
       $ roundtrips (Map.fromFoldable [(Stringy "A" /\ "B"),(Stringy "C" /\ "D")])
     it "roundtrips Map with Int newtype keys"
       $ roundtrips (Map.fromFoldable [(Inty 4 /\ "B"),(Inty 8 /\ "D")])
+    it "roundtrips BigInt" do
+      let
+        inputStr = """{ "number":1, "big": 18014398509481982, "smallBig": 10 }"""
+        expected = """{"smallBig":"10","number":1,"big":"18014398509481982"}"""
+        parsed ∷ _ ({ number ∷ Int, big ∷ BigInt, smallBig ∷ BigInt })
+        parsed = readJSON inputStr
+        stringified = parsed <#> writeJSON
+      stringified `shouldEqual` (Right expected)
+      -- [TODO] Comment in as soon as bug in big-integers is fixed
+    -- it "roundtrips BigInt (2)" do
+    --   let
+    --     smallBig = BigInt.fromInt 10
+    --     big = unsafePartial $ fromJust $ BigInt.fromString "18014398509481982"
+        
+    --     expected = { big, smallBig }
+    --     json = spy "json" $ writeJSON expected
 
+    --     parsed ∷ _ ({ big ∷ BigInt, smallBig ∷ BigInt })
+    --     parsed = readJSON json
+    --   (spy "parsed" parsed) `shouldEqual` (Right expected)
   describe "works on record types" do
     it "roundtrips" do
       roundtrips { a: 12, b: "54" }
@@ -111,4 +131,4 @@ derive newtype instance Show Inty
 derive newtype instance Eq Inty
 derive newtype instance Ord Inty
 derive newtype instance WriteForeign Inty
-derive newtype instance ReadForeign Inty
+derive newtype instance ReadForeign Inty