oxc-project/oxc · error · napi::Error

ObjectExpected

ObjectExpected

Error message

Expected a RegExp object

What it means

N-API conversion error from JsRegExp::from_napi_value: the incoming JS value was checked with instanceof against the global RegExp constructor and failed, so the value cannot be treated as a RegExp by the binding.

Source

Thrown at crates/oxc_napi/src/js_reg_exp.rs:48

        "RegExp"
    }

    fn value_type() -> napi::ValueType {
        napi::ValueType::Object
    }
}

impl ValidateNapiValue for JsRegExp {}

impl FromNapiValue for JsRegExp {
    unsafe fn from_napi_value(env: sys::napi_env, napi_val: sys::napi_value) -> napi::Result<Self> {
        let object = Object::from_raw(env, napi_val);
        let env = Env::from(env);
        let global = env.get_global()?;
        let constructor = global.get_named_property::<Function<Unknown, ()>>("RegExp")?;

        if !object.instanceof(constructor)? {
            return Err(Error::new(Status::ObjectExpected, "Expected a RegExp object"));
        }

        Ok(Self {
            source: object.get_named_property::<String>("source")?,
            flags: object.get_named_property::<String>("flags")?,
            last_index: object.get_named_property::<u32>("lastIndex").unwrap_or_default(),
        })
    }
}

impl ToNapiValue for JsRegExp {
    unsafe fn to_napi_value(env: sys::napi_env, value: Self) -> napi::Result<sys::napi_value> {
        let global = Env::from(env).get_global()?;
        let constructor =
            global.get_named_property::<Function<FnArgs<(String, String)>, Unknown>>("RegExp")?;
        let object = constructor.new_instance(FnArgs::from((value.source, value.flags)))?;
        let mut object = Object::from_raw(env, object.raw());
        if value.last_index != 0 {

View on GitHub (pinned to e1e7af627c)

Solutions

1. Pass a RegExp literal (e.g. /abc/) or new RegExp(...) from JS
2. Check value instanceof RegExp on the JS side before calling the binding
3. Accept a string|RegExp union in the API and construct a RegExp internally

When it happens

Trigger: Thrown at crates/oxc_napi/src/js_reg_exp.rs:48 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of oxc-project/oxc@e1e7af627c (2026-08-20). Data as JSON: /api/errors/788b33bdfd451695. Report an issue: GitHub.