Handle exceptions from JSON::stringify

crates/js-sys/src/lib.rs

@@ -2683,8 +2683,8 @@ extern "C" {
     /// specified.
     ///
     /// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify
-    #[wasm_bindgen(static_method_of = JSON)]
-    pub fn stringify(obj: &JsValue) -> JsString;
+    #[wasm_bindgen(catch, static_method_of = JSON)]
+    pub fn stringify(obj: &JsValue) -> Result<JsString, JsValue>;
 
 }
 

crates/js-sys/tests/wasm/JSON.js

@@ -0,0 +1,4 @@
+exports.set_in_object = function(obj, name, value) {
+    obj[name] = value;
+};
+

crates/js-sys/tests/wasm/JSON.rs

@@ -1,8 +1,15 @@
 use wasm_bindgen::JsValue;
 use wasm_bindgen_test::*;
+use wasm_bindgen::prelude::*;
 use wasm_bindgen::JsCast;
 use js_sys::*;
 
+
+#[wasm_bindgen(module = "tests/wasm/JSON.js")]
+extern {
+    fn set_in_object(obj: &Object, name: &str, value: &JsValue);
+}
+
 #[wasm_bindgen_test]
 fn parse_array() {
 
@@ -63,7 +70,22 @@ fn stringify() {
     arr.push(&JsValue::from(true));
     arr.push(&JsValue::from("hello"));
 
-    let str = JSON::stringify(&JsValue::from(arr));
+    let str = JSON::stringify(&JsValue::from(arr)).unwrap();
     let rust_str: String = From::from(str);
     assert_eq!(rust_str, "[1,true,\"hello\"]");
-}
+}
+
+#[wasm_bindgen_test]
+fn stringify_error() {
+    let func = Function::new_no_args("throw new Error(\"rust really rocks\")");
+    let obj = Object::new();
+    set_in_object(&obj, "toJSON", &JsValue::from(func));
+
+    let result = JSON::stringify(&JsValue::from(obj));
+    assert!(result.is_err());
+    let err_obj = result.unwrap_err();
+    assert!(err_obj.is_instance_of::<Error>());
+    let err: &Error = err_obj.dyn_ref().unwrap();
+    let err_msg: String = From::from(err.message());
+    assert!(err_msg.contains("rust really rocks"));
+}