ECMAScript® 2024 Language Specification

Draft ECMA-262 / February 15, 2024

9.6 InitializeHostDefinedRealm ( )

The abstract operation InitializeHostDefinedRealm takes no arguments and returns either a normal completion containing unused or a throw completion. It performs the following steps when called:

  1. Let realm be CreateRealm().
  2. Let newContext be a new execution context.
  3. Set the Function of newContext to null.
  4. Set the Realm of newContext to realm.
  5. Set the ScriptOrModule of newContext to null.
  6. Push newContext onto the execution context stack; newContext is now the running execution context.
  7. If the host requires use of an exotic object to serve as realm's global object, let global be such an object created in a host-defined manner. Otherwise, let global be undefined, indicating that an ordinary object should be created as the global object.
  8. If the host requires that the this binding in realm's global scope return an object other than the global object, let thisValue be such an object created in a host-defined manner. Otherwise, let thisValue be undefined, indicating that realm's global this binding should be the global object.
  9. Perform SetRealmGlobalObject(realm, global, thisValue).
  10. Let globalObj be ? SetDefaultGlobalBindings(realm).
  11. Create any host-defined global object properties on globalObj.
  12. Return unused.