skip bit string conversion for js runtime

2 files changed, 10 insertions, 21 deletions

diff --git a/src/gleam/json.gleam b/src/gleam/json.gleam
index b8c49f6..ad61a94 100644
--- a/src/gleam/json.gleam
+++ b/src/gleam/json.gleam
@@ -62,7 +62,7 @@ if javascript {
   }
 
   external fn decode_string(String) -> Result(Dynamic, DecodeError) =
-    "../gleam_json_ffi.mjs" "decode_string"
+    "../gleam_json_ffi.mjs" "decode"
 }
 
 /// Decode a JSON bit string into dynamically typed data which can be decoded
@@ -94,18 +94,18 @@ pub fn decode_bits(
   |> result.map_error(UnexpectedFormat)
 }
 
-fn decode_to_dynamic(bit_string: BitString) -> Result(Dynamic, DecodeError) {
-  do_decode_to_dynamic(bit_string)
-}
-
 if erlang {
-  external fn do_decode_to_dynamic(BitString) -> Result(Dynamic, DecodeError) =
+  external fn decode_to_dynamic(BitString) -> Result(Dynamic, DecodeError) =
     "gleam_json_ffi" "decode"
 }
 
 if javascript {
-  external fn do_decode_to_dynamic(BitString) -> Result(Dynamic, DecodeError) =
-    "../gleam_json_ffi.mjs" "decode"
+  fn decode_to_dynamic(json: BitString) -> Result(Dynamic, DecodeError) {
+    case bit_string.to_string(json) {
+      Ok(string) -> decode_string(string)
+      Error(Nil) -> Error(UnexpectedByte("", 0))
+    }
+  }
 }
 
 /// Convert a JSON value into a string.
diff --git a/src/gleam_json_ffi.mjs b/src/gleam_json_ffi.mjs
index 64d90b0..a66a17d 100644
--- a/src/gleam_json_ffi.mjs
+++ b/src/gleam_json_ffi.mjs
@@ -22,18 +22,7 @@ export function do_null() {
   return null
 }
 
-export function decode(bit_string) {
-  const stringResult = bit_string_to_string(bit_string)
-  if (!stringResult.isOk()) return stringResult
-  try {
-    const result = JSON.parse(stringResult[0])
-    return new Ok(result)
-  } catch (err) {
-    return new Error(getJsonDecodeError(err))
-  }
-}
-
-export function decode_string_to_dynamic(string) {
+export function decode(string) {
   try {
     const result = JSON.parse(string)
     return new Ok(result)
@@ -45,7 +34,7 @@ export function decode_string_to_dynamic(string) {
 function getJsonDecodeError(stdErr) {
   if (isUnexpectedByte(stdErr)) return new toUnexpectedByteError(stdErr)
   if (isUnexpectedEndOfInput(stdErr)) return new UnexpectedEndOfInput()
-  return undefined
+  return new UnexpectedByte('', 0)
 }
 
 function isUnexpectedEndOfInput(err) {