[oden-js] Get module exports

oden-js/src/value.rs

@@ -1,6 +1,6 @@
 use crate::{AtomRef, ContextRef, Error, Result, Runtime, RustFunction};
 use oden_js_sys as sys;
-use std::ffi::CStr;
+use std::ffi::{CStr, CString};
 use std::fmt;
 use std::ops::{Deref, DerefMut};
 
@@ -309,6 +309,25 @@ impl ValueRef {
 
         Ok(result)
     }
+
+    pub fn get_module_export(&self, ctx: &ContextRef, export: &str) -> Result<Value> {
+        if self.value_type() != ValueType::Module {
+            return Err(Error::InvalidType {
+                expected: ValueType::Bool,
+                found: self.value_type(),
+            });
+        }
+
+        let c_value = match CString::new(export) {
+            Ok(cs) => Ok(cs),
+            Err(_) => Err(Error::UnexpectedNul),
+        }?;
+
+        unsafe {
+            let module = sys::JS_ValueGetPtr(self.val) as *mut sys::JSModuleDef;
+            ctx.check_exception(sys::JS_GetModuleExport(ctx.ctx, module, c_value.into_raw()))
+        }
+    }
 }
 
 impl<'ctx> fmt::Debug for ValueRef {