diff --git a/moon.mod.json b/moon.mod.json
index 41ef90e..4ea3740 100644
--- a/moon.mod.json
+++ b/moon.mod.json
@@ -1,6 +1,6 @@
 {
   "name": "rami3l/js-ffi",
-  "version": "0.3.0",
+  "version": "0.3.1",
   "readme": "README.md",
   "repository": "",
   "license": "Apache-2.0",
diff --git a/src/js/async.mbt b/src/js/async.mbt
index 44718eb..d8c9870 100644
--- a/src/js/async.mbt
+++ b/src/js/async.mbt
@@ -1,7 +1,7 @@
 ///|
 pub async fn[T, E : Error] suspend(
   f : ((T) -> Unit, (E) -> Unit) -> Unit
-) -> T!E = "%async.suspend"
+) -> T raise E = "%async.suspend"
 
 ///|
 pub fn async_run(f : async () -> Unit) -> Unit = "%async.run"
@@ -14,7 +14,8 @@ pub fn async_run(f : async () -> Unit) -> Unit = "%async.run"
 /// (i.e. this `Promise` is not handled by an external JavaScript API).
 /// This makes sure that when the operation in the this `Promise` errs out,
 /// the error is caught by the MoonBit runtime.
-pub extern type Promise
+#external
+pub type Promise
 
 ///|
 extern "js" fn Promise::wait_ffi(
@@ -25,8 +26,8 @@ extern "js" fn Promise::wait_ffi(
   #| (self, on_ok, on_err) => self.then((t) => on_ok(t), (e) => on_err(e))
 
 ///|
-pub async fn Promise::wait(self : Promise) -> Value! {
-  suspend!(fn(k, ke) { Promise::wait_ffi(self, k, fn(e) { ke(Error_(e)) }) })
+pub async fn Promise::wait(self : Promise) -> Value raise {
+  suspend(fn(k, ke) { Promise::wait_ffi(self, k, fn(e) { ke(Error_(e)) }) })
 }
 
 ///|
@@ -38,18 +39,18 @@ pub async fn Promise::wait(self : Promise) -> Value! {
 /// This makes sure that when `op` errs out, the error is caught by the MoonBit runtime.
 ///
 /// If you don't care about the result of the operation, you can use `spawn_detach` instead.
-pub fn[T] Promise::unsafe_new(op : async () -> T!) -> Promise {
-  Promise::new_ffi(fn() { Value::cast_from(op!()) })
+pub fn[T] Promise::unsafe_new(op : async () -> T raise) -> Promise {
+  Promise::new_ffi(fn() { Value::cast_from(op()) })
 }
 
 ///|
-extern "js" fn Promise::new_ffi(op : async () -> Value!) -> Promise =
+extern "js" fn Promise::new_ffi(op : async () -> Value raise) -> Promise =
   #| (op) => new Promise((k, ke) => op(k, ke))
 
 ///|
-pub fn[T, E : Error] spawn_detach(op : async () -> T!E) -> Unit {
+pub fn[T, E : Error] spawn_detach(op : async () -> T raise E) -> Unit {
   async_run(fn() {
-    try op!() |> ignore catch {
+    try op() |> ignore catch {
       _ => ()
     }
   })
@@ -62,21 +63,23 @@ pub extern "js" fn Promise::all(promises : Array[Promise]) -> Promise = "(ps) =>
 
 ///|
 /// Wraps each given `async fn` in a `Promise` and waits for all of them to resolve.
-pub async fn[T] async_all!(ops : Array[async () -> T!]) -> Array[T] {
-  async_all_raw!(ops.map(fn(op) { async fn!() { Value::cast_from(op!()) } })).map(
+pub async fn[T] async_all(ops : Array[async () -> T raise]) -> Array[T] raise {
+  async_all_raw(ops.map(fn(op) { async fn() raise { Value::cast_from(op()) } })).map(
     Value::cast,
   )
 }
 
 ///|
-async fn async_all_raw!(ops : Array[async () -> Value!]) -> Array[Value] {
-  Promise::all(ops.map(Promise::unsafe_new)).wait!().cast()
+async fn async_all_raw(
+  ops : Array[async () -> Value raise]
+) -> Array[Value] raise {
+  Promise::all(ops.map(Promise::unsafe_new)).wait().cast()
 }
 
 ///|
-pub fn async_test(op : async () -> Unit!) -> Unit {
+pub fn async_test(op : async () -> Unit raise) -> Unit {
   async_run(async fn() {
-    try op!() catch {
+    op() catch {
       e => {
         println("ERROR in `async_test`: \{e}")
         panic()
diff --git a/src/js/async_test.mbt b/src/js/async_test.mbt
index 6bcda65..f1de729 100644
--- a/src/js/async_test.mbt
+++ b/src/js/async_test.mbt
@@ -5,7 +5,7 @@ async fn op1() -> String? {
 
 ///|
 async fn op2() -> String? {
-  guard op1!() is Some(prefix)
+  guard op1() is Some(prefix)
   Some(prefix + ", World")
 }
 
@@ -16,19 +16,20 @@ async fn op3() -> String? {
 
 ///|
 test "Promise::wait" {
-  @js.async_test(fn!() {
+  @js.async_test(fn() raise {
     // Promise::unsafe_new + Promise::wait is a noop.
-    let res = @js.Promise::unsafe_new(fn() { op1!() }).wait!()
-    assert_eq!(res.cast(), Some("Hello"))
+    let res = @js.Promise::unsafe_new(fn() { op1() }).wait()
+    assert_eq(res.cast(), Some("Hello"))
   })
 }
 
 ///|
 test "async_all" {
-  @js.async_test(fn!() {
-    assert_eq!(
-      @js.async_all!([fn() { op2!() }, fn() { op1!() }, fn() { op3!() }]),
-      [Some("Hello, World"), Some("Hello"), None],
-    )
+  @js.async_test(fn() raise {
+    assert_eq(@js.async_all([fn() { op2() }, fn() { op1() }, fn() { op3() }]), [
+      Some("Hello, World"),
+      Some("Hello"),
+      None,
+    ])
   })
 }
diff --git a/src/js/error.mbt b/src/js/error.mbt
index 66bf523..d633585 100644
--- a/src/js/error.mbt
+++ b/src/js/error.mbt
@@ -1,5 +1,5 @@
 ///|
-pub type! Error_ Value
+pub suberror Error_ Value
 
 ///|
 extern "js" fn Error_::cause_ffi(self : Value) -> Value = "(self) => self.cause"
@@ -34,7 +34,7 @@ extern "js" fn Error_::wrap_ffi(
 pub fn[T] Error_::wrap(
   op : () -> Value,
   map_ok~ : (Value) -> T = Value::cast
-) -> T!Error_ {
+) -> T raise Error_ {
   let mut res : Result[Value, Error_] = Ok(Value::undefined())
   Error_::wrap_ffi(op, fn(v) { res = Ok(v) }, fn(e) { res = Err(Error_(e)) })
   match res {
diff --git a/src/js/js.mbti b/src/js/js.mbti
index 618c059..cef0af2 100644
--- a/src/js/js.mbti
+++ b/src/js/js.mbti
@@ -5,64 +5,38 @@ import(
 )
 
 // Values
-async fn[T] async_all(Array[() -> T!]) -> Array[T]!
+async fn[T] async_all(Array[() -> T raise]) -> Array[T] raise
 
 let async_iterator : Symbol
 
 fn async_run(() -> Unit) -> Unit
 
-fn async_test(() -> Unit!) -> Unit
-
-fn extends(Value, Value) -> Value
-
-fn[T] get_with_index(Value, Int) -> T
-
-fn[T] get_with_string(Value, String) -> T
-
-fn[T] get_with_symbol(Value, Symbol) -> T
+fn async_test(() -> Unit raise) -> Unit
 
 let globalThis : Value
 
-fn is_bool(Value) -> Bool
-
-fn is_null(Value) -> Bool
-
-fn is_number(Value) -> Bool
-
-fn is_object(Value) -> Bool
-
-fn is_string(Value) -> Bool
-
-fn is_symbol(Value) -> Bool
-
-fn is_undefined(Value) -> Bool
-
 let iterator : Symbol
 
 fn require(String, keys~ : Array[String] = ..) -> Value
 
-fn[T] set_with_index(Value, Int, T) -> Unit
-
-fn[T] set_with_string(Value, String, T) -> Unit
-
-fn[T] set_with_symbol(Value, Symbol, T) -> Unit
-
-fn[T, E : Error] spawn_detach(() -> T!E) -> Unit
+fn[T, E : Error] spawn_detach(() -> T raise E) -> Unit
 
-async fn[T, E : Error] suspend(((T) -> Unit, (E) -> Unit) -> Unit) -> T!E
+async fn[T, E : Error] suspend(((T) -> Unit, (E) -> Unit) -> Unit) -> T raise E
 
 // Types and methods
-pub type! Error_ Value
+pub suberror Error_ Value
 fn Error_::cause(Self) -> Value?
-fn[T] Error_::wrap(() -> Value, map_ok~ : (Value) -> T = ..) -> T!Self
+fn[T] Error_::wrap(() -> Value, map_ok~ : (Value) -> T = ..) -> T raise Self
 impl Show for Error_
 
 type Nullable[_]
 fn[T] Nullable::from_option(T?) -> Self[T]
+#deprecated
 fn[T] Nullable::get_exn(Self[T]) -> T
 fn[T] Nullable::is_null(Self[T]) -> Bool
 fn[T] Nullable::null() -> Self[T]
 fn[T] Nullable::to_option(Self[T]) -> T?
+fn[T] Nullable::unwrap(Self[T]) -> T
 
 pub type Object Value
 fn[K, V] Object::extend_iter(Self, Iter[(K, V)]) -> Unit
@@ -72,6 +46,7 @@ fn[K, V] Object::from_iter(Iter[(K, V)]) -> Self
 fn[K, V] Object::from_iter2(Iter2[K, V]) -> Self
 fn Object::from_value(Value) -> Optional[Self]
 fn Object::from_value_unchecked(Value) -> Self
+fn Object::inner(Self) -> Value
 fn Object::new() -> Self
 fn[K, V] Object::op_get(Self, K) -> V
 fn[K, V] Object::op_set(Self, K, V) -> Unit
@@ -79,15 +54,18 @@ fn Object::to_value(Self) -> Value
 
 type Optional[_]
 fn[T] Optional::from_option(T?) -> Self[T]
+#deprecated
 fn[T] Optional::get_exn(Self[T]) -> T
 fn[T] Optional::is_undefined(Self[T]) -> Bool
 fn[T] Optional::to_option(Self[T]) -> T?
 fn[T] Optional::undefined() -> Self[T]
+fn[T] Optional::unwrap(Self[T]) -> T
 
-pub extern type Promise
+#external
+pub type Promise
 fn Promise::all(Array[Self]) -> Self
-fn[T] Promise::unsafe_new(() -> T!) -> Self
-async fn Promise::wait(Self) -> Value!
+fn[T] Promise::unsafe_new(() -> T raise) -> Self
+async fn Promise::wait(Self) -> Value raise
 
 type Symbol
 fn Symbol::make() -> Self
@@ -179,7 +157,8 @@ fn[A, B, C, D, E, F : Cast, G, H] Union8::to5(Self[A, B, C, D, E, F, G, H]) -> F
 fn[A, B, C, D, E, F, G : Cast, H] Union8::to6(Self[A, B, C, D, E, F, G, H]) -> G?
 fn[A, B, C, D, E, F, G, H : Cast] Union8::to7(Self[A, B, C, D, E, F, G, H]) -> H?
 
-pub extern type Value
+#external
+pub type Value
 fn[Arg, Result] Value::apply(Self, Array[Arg]) -> Result
 fn[Arg, Result] Value::apply_with_index(Self, Int, Array[Arg]) -> Result
 fn[Arg, Result] Value::apply_with_string(Self, String, Array[Arg]) -> Result
@@ -187,8 +166,8 @@ fn[Arg, Result] Value::apply_with_symbol(Self, Symbol, Array[Arg]) -> Result
 fn[T] Value::cast(Self) -> T
 fn[T] Value::cast_from(T) -> Self
 fn Value::extends(Self, Self) -> Self
-fn Value::from_json(Json) -> Self!
-fn Value::from_json_string(String) -> Self!
+fn Value::from_json(Json) -> Self raise
+fn Value::from_json_string(String) -> Self raise
 fn[T] Value::get_with_index(Self, Int) -> T
 fn[T] Value::get_with_string(Self, String) -> T
 fn[T] Value::get_with_symbol(Self, Symbol) -> T
@@ -206,8 +185,8 @@ fn[Arg, Result] Value::new_with_symbol(Self, Symbol, Array[Arg]) -> Result
 fn[T] Value::set_with_index(Self, Int, T) -> Unit
 fn[T] Value::set_with_string(Self, String, T) -> Unit
 fn[T] Value::set_with_symbol(Self, Symbol, T) -> Unit
-fn Value::to_json(Self) -> Json!
-fn Value::to_json_string(Self) -> String!
+fn Value::to_json(Self) -> Json raise
+fn Value::to_json_string(Self) -> String raise
 fn Value::to_string(Self) -> String
 impl Show for Value
 impl @json.FromJson for Value
diff --git a/src/js/null.mbt b/src/js/null.mbt
index e6ae8fa..bb13675 100644
--- a/src/js/null.mbt
+++ b/src/js/null.mbt
@@ -1,5 +1,6 @@
 ///|
-extern type Nullable[_]
+#external
+type Nullable[_]
 
 ///|
 pub fn[T] Nullable::is_null(self : Nullable[T]) -> Bool {
@@ -7,8 +8,17 @@ pub fn[T] Nullable::is_null(self : Nullable[T]) -> Bool {
 }
 
 ///|
+#deprecated("get_exn does not check for null values. Use unwrap instead")
 pub fn[T] Nullable::get_exn(self : Nullable[T]) -> T = "%identity"
 
+///| Unwraps the nullable value, panicking if it is null.
+pub fn[T] Nullable::unwrap(self : Nullable[T]) -> T {
+  if self.is_null() {
+    abort("Cannot unwrap a null value")
+  }
+  self.get_exn()
+}
+
 ///|
 pub fn[T] Nullable::to_option(self : Nullable[T]) -> T? {
   guard not(Value::cast_from(self).is_null()) else { None }
diff --git a/src/js/object.mbt b/src/js/object.mbt
index 1cc542f..c6e1edc 100644
--- a/src/js/object.mbt
+++ b/src/js/object.mbt
@@ -11,7 +11,7 @@ pub fn Object::from_value_unchecked(value : Value) -> Object {
 
 ///|
 pub fn Object::to_value(self : Object) -> Value {
-  self._
+  self.inner()
 }
 
 ///|
@@ -52,10 +52,10 @@ pub fn[K, V] Object::from_iter2(it : Iter2[K, V]) -> Object {
 
 ///|
 pub fn[K, V] Object::op_get(self : Object, key : K) -> V {
-  self._.get_ffi(Value::cast_from(key)).cast()
+  self.inner().get_ffi(Value::cast_from(key)).cast()
 }
 
 ///|
 pub fn[K, V] Object::op_set(self : Object, key : K, value : V) -> Unit {
-  self._.set_ffi(Value::cast_from(key), Value::cast_from(value))
+  self.inner().set_ffi(Value::cast_from(key), Value::cast_from(value))
 }
diff --git a/src/js/object_test.mbt b/src/js/object_test.mbt
index 94b16bd..7e83c51 100644
--- a/src/js/object_test.mbt
+++ b/src/js/object_test.mbt
@@ -1,12 +1,12 @@
 ///|
 test "Object::extend_object" {
   let obj = @js.Object::from_value_unchecked(
-    @json.from_json!({ "a": 1, "b": 2, "c": 3 }),
+    @json.from_json({ "a": 1, "b": 2, "c": 3 }),
   )
   let obj1 = @js.Object::from_value_unchecked(
-    @json.from_json!({ "b": [6, 7], "d": 44, "a": 55 }),
+    @json.from_json({ "b": [6, 7], "d": 44, "a": 55 }),
   )
-  @json.inspect!(obj.extend_object(obj1)._.to_json!(), content={
+  @json.inspect(obj.extend_object(obj1).inner().to_json(), content={
     "a": 55,
     "b": [6, 7],
     "c": 3,
diff --git a/src/js/optional.mbt b/src/js/optional.mbt
index 492bddf..a98f3f4 100644
--- a/src/js/optional.mbt
+++ b/src/js/optional.mbt
@@ -1,14 +1,24 @@
 ///|
-extern type Optional[_]
+#external
+type Optional[_]
 
 ///|
 pub fn[T] Optional::is_undefined(self : Optional[T]) -> Bool {
   self |> Value::cast_from |> Value::is_undefined
 }
 
-///|
+///| 
+#deprecated("get_exn does not check for undefined values. Use unwrap instead")
 pub fn[T] Optional::get_exn(self : Optional[T]) -> T = "%identity"
 
+///| Unwraps the optional value, panicking if it is undefined.
+pub fn[T] Optional::unwrap(self : Self[T]) -> T {
+  if self.is_undefined() {
+    abort("Cannot unwrap an undefined value")
+  }
+  self.get_exn()
+}
+
 ///|
 pub fn[T] Optional::to_option(self : Optional[T]) -> T? {
   if Value::cast_from(self).is_undefined() {
diff --git a/src/js/require.mbt b/src/js/require.mbt
index fc2e7f1..10f9596 100644
--- a/src/js/require.mbt
+++ b/src/js/require.mbt
@@ -3,7 +3,7 @@ extern "js" fn require_ffi(path : String) -> Value = "(path) => require(path)"
 
 ///|
 pub fn require(path : String, keys~ : Array[String] = []) -> Value {
-  keys.fold(init=require_ffi(path), fn {
-    acc, key => acc.get_ffi(Value::cast_from(key))
-  })
+  keys.fold(init=require_ffi(path), (acc, key) => acc.get_ffi(
+    Value::cast_from(key),
+  ))
 }
diff --git a/src/js/symbol.mbt b/src/js/symbol.mbt
index f4fd347..d579238 100644
--- a/src/js/symbol.mbt
+++ b/src/js/symbol.mbt
@@ -1,5 +1,6 @@
 ///|
-extern type Symbol
+#external
+type Symbol
 
 ///|
 pub fn Symbol::make() -> Symbol {
diff --git a/src/js/union.mbt b/src/js/union.mbt
index 9cfa941..ff46a18 100644
--- a/src/js/union.mbt
+++ b/src/js/union.mbt
@@ -1,5 +1,6 @@
 ///| Union type `A | B` for JavaScript values.
-extern type Union2[_, _]
+#external
+type Union2[_, _]
 
 ///|
 pub fn[A : Cast, B] Union2::to0(self : Union2[A, B]) -> A? {
@@ -22,7 +23,8 @@ pub fn[A, B : Cast] Union2::from1(value : B) -> Union2[A, B] {
 }
 
 ///| Union type `A | B | C` for JavaScript values.
-extern type Union3[_, _, _]
+#external
+type Union3[_, _, _]
 
 ///|
 pub fn[A : Cast, B, C] Union3::to0(self : Union3[A, B, C]) -> A? {
@@ -55,7 +57,8 @@ pub fn[A, B, C : Cast] Union3::from2(value : C) -> Union3[A, B, C] {
 }
 
 ///| Union type `A | B | C | D` for JavaScript values.
-extern type Union4[_, _, _, _]
+#external
+type Union4[_, _, _, _]
 
 ///|
 pub fn[A : Cast, B, C, D] Union4::to0(self : Union4[A, B, C, D]) -> A? {
@@ -98,7 +101,8 @@ pub fn[A, B, C, D : Cast] Union4::from3(value : D) -> Union4[A, B, C, D] {
 }
 
 ///| Union type `A | B | C | D | E` for JavaScript values.
-extern type Union5[_, _, _, _, _]
+#external
+type Union5[_, _, _, _, _]
 
 ///|
 pub fn[A : Cast, B, C, D, E] Union5::to0(self : Union5[A, B, C, D, E]) -> A? {
@@ -151,7 +155,8 @@ pub fn[A, B, C, D, E : Cast] Union5::from4(value : E) -> Union5[A, B, C, D, E] {
 }
 
 ///| Union type `A | B | C | D | E | F` for JavaScript values.
-extern type Union6[_, _, _, _, _, _]
+#external
+type Union6[_, _, _, _, _, _]
 
 ///|
 pub fn[A : Cast, B, C, D, E, F] Union6::to0(
@@ -238,7 +243,8 @@ pub fn[A, B, C, D, E, F : Cast] Union6::from5(
 }
 
 ///| Union type `A | B | C | D | E | F | G` for JavaScript values.
-extern type Union7[_, _, _, _, _, _, _]
+#external
+type Union7[_, _, _, _, _, _, _]
 
 ///|
 pub fn[A : Cast, B, C, D, E, F, G] Union7::to0(
@@ -339,7 +345,8 @@ pub fn[A, B, C, D, E, F, G : Cast] Union7::from6(
 }
 
 ///| Union type `A | B | C | D | E | F | G | H` for JavaScript values.
-extern type Union8[_, _, _, _, _, _, _, _]
+#external
+type Union8[_, _, _, _, _, _, _, _]
 
 ///|
 pub fn[A : Cast, B, C, D, E, F, G, H] Union8::to0(
diff --git a/src/js/value.mbt b/src/js/value.mbt
index 66c1edf..1b48672 100644
--- a/src/js/value.mbt
+++ b/src/js/value.mbt
@@ -1,5 +1,6 @@
 ///|
-pub extern type Value
+#external
+pub type Value
 
 ///|
 pub fn[T] Value::cast_from(value : T) -> Value = "%identity"
@@ -121,8 +122,8 @@ pub fn[Arg, Result] Value::new_with_index(
 }
 
 ///|
-pub fn Value::from_json!(json : Json) -> Value {
-  @json.from_json!(json)
+pub fn Value::from_json(json : Json) -> Value raise {
+  @json.from_json(json)
 }
 
 ///|
@@ -136,36 +137,36 @@ pub impl @json.FromJson for Value with from_json(json : Json, path) {
     Array(xs) => {
       let acc = Array::new(capacity=xs.length())
       for x in xs {
-        acc.push((@json.from_json!(x, path~) : Value))
+        acc.push((@json.from_json(x, path~) : Value))
       }
       Value::cast_from(acc)
     }
     Object(kvs) => {
       let acc = Object::new()
       for k, v in kvs {
-        acc._.set_with_string(k, (@json.from_json!(v, path~) : Value))
+        acc.inner().set_with_string(k, (@json.from_json(v, path~) : Value))
       }
-      acc._
+      acc.inner()
     }
   }
 }
 
 ///|
-pub fn Value::from_json_string!(str : String) -> Value {
-  Error_::wrap!(fn() { Value::from_json_string_ffi(str) })
+pub fn Value::from_json_string(str : String) -> Value raise {
+  Error_::wrap(fn() { Value::from_json_string_ffi(str) })
 }
 
 ///|
 extern "js" fn Value::from_json_string_ffi(str : String) -> Value = "JSON.parse"
 
 ///|
-pub fn Value::to_json_string!(self : Value) -> String {
-  Error_::wrap!(fn() { self.to_json_string_ffi() })
+pub fn Value::to_json_string(self : Value) -> String raise {
+  Error_::wrap(fn() { self.to_json_string_ffi() })
 }
 
 ///|
-pub fn Value::to_json!(self : Value) -> Json {
-  @json.parse!(self.to_json_string!())
+pub fn Value::to_json(self : Value) -> Json raise {
+  @json.parse(self.to_json_string())
 }
 
 ///|
diff --git a/src/js/value_test.mbt b/src/js/value_test.mbt
index b047c43..533c7e5 100644
--- a/src/js/value_test.mbt
+++ b/src/js/value_test.mbt
@@ -60,12 +60,12 @@ let json_str_pretty =
   #|}
 
 ///|
-let json_val : @js.Value = @js.Value::from_json_string?(json_str_pretty).unwrap()
+let json_val : @js.Value = (try? @js.Value::from_json_string(json_str_pretty)).unwrap()
 
 ///|
 test "Value::to_json_string" {
-  inspect!(
-    json_val.to_json_string!(),
+  inspect(
+    json_val.to_json_string(),
     content=
       #|{"_id":"67a6c712bc218526d5e1b516","index":0,"guid":"74e69a18-680a-4a74-a401-e386c30d0a35","isActive":false,"balance":"$3,140.03","picture":"http://placehold.it/32x32","age":33,"eyeColor":"blue","name":"Burt Dominguez","gender":"male","company":"GEEKWAGON","email":"burtdominguez@geekwagon.com","phone":"+1 (913) 583-3488","address":"379 Essex Street, Fresno, Minnesota, 5304","about":"Proident velit ullamco cillum occaecat irure eu proident commodo consectetur est ut elit consectetur.","registered":"2020-12-06T01:54:20 -08:00","latitude":71.680916,"longitude":-88.552886,"tags":["aute","occaecat","qui","esse","commodo","sint","proident"],"friends":[{"id":0,"name":"Gilliam Mcgowan"},{"id":1,"name":"Bryan Stanton"},{"id":2,"name":"Jenifer Elliott"}],"greeting":"Hello, Burt Dominguez! You have 4 unread messages.","favoriteFruit":"apple"}
     ,
@@ -74,13 +74,13 @@ test "Value::to_json_string" {
 
 ///|
 test "Value::to_json" {
-  assert_eq!(json_val.to_json!(), json)
+  assert_eq(json_val.to_json(), json)
 }
 
 ///|
 test "Value::from_json" {
-  assert_eq!(
-    @js.Value::from_json!(json).to_json_string!(),
-    json_val.to_json_string!(),
+  assert_eq(
+    @js.Value::from_json(json).to_json_string(),
+    json_val.to_json_string(),
   )
 }