fix(python): imports between subpackages are broken

packages/@jsii/python-runtime/tests/test_compliance.py

@@ -70,9 +70,11 @@
     StructUnionConsumer,
     SomeTypeJsii976,
     StructParameterType,
-    AnonymousImplementationProvider
+    AnonymousImplementationProvider,
+    UpcasingReflectable,
 )
 from scope.jsii_calc_lib import IFriendly, EnumFromScopedModule, Number
+from scope.jsii_calc_lib.submodule import IReflectable, ReflectableEntry
 
 
 # Note: The names of these test functions have been chosen to map as closely to the
@@ -1168,3 +1170,15 @@ def test_collection_of_interfaces_map_of_structs():
 def test_collection_of_interfaces_map_of_interfaces():
     for elt in InterfaceCollections.map_of_interfaces().values():
         assert getattr(elt, "ring") is not None
+
+
+def test_dependency_submodule_types_are_usable():
+    subject = UpcasingReflectable({ 'foo': 'bar' })
+
+    assert UpcasingReflectable.REFLECTOR.as_map(subject) == { 'FOO': 'bar' }
+
+
+def test_load_submodules():
+    from jsii_calc.submodule import nested_submodule
+    import jsii_calc.submodule
+

packages/@jsii/spec/lib/assembly.ts

@@ -161,6 +161,14 @@ export interface AssemblyConfiguration extends Targetable {
  * An entity on which targets may be configured.
  */
 export interface Targetable {
+  /**
+   * Submodules defined in this assembly, if any, associated with their
+   * designated targets configuration.
+   *
+   * @default none
+   */
+  submodules?: { [fqn: string]: { targets?: AssemblyTargets } };
+
   /**
    * A map of target name to configuration, which is used when generating
    * packages for various languages.