Function JS_Eval 

pub unsafe fn JS_Eval(
    _ctx: *mut JSContext,
    input: *const i8,
    input_len: usize,
    _filename: *const i8,
    _eval_flags: i32,
) -> JSValue

Safety

The caller must ensure that ctx is a valid pointer to a JSContext, and that input points to valid UTF-8 data of length input_len.