support default state in x-interaction

components/x-interaction/__tests__/x-interaction.test.jsx

@@ -260,6 +260,20 @@ describe('x-interaction', () => {
 				target.find(Base).prop('quux')
 			).toBe(10);
 		});
+
+		it('should get default state from second argument', async () => {
+			const Base = () => null;
+			const Wrapped = withActions({}, {
+				foo: 5
+			})(Base);
+
+			const target = mount(<Wrapped />);
+
+			expect(
+				target.find(Base).prop('foo')
+			).toBe(5);
+		});
+
 	});
 
 	describe.skip('server rendering');

components/x-interaction/src/Interaction.jsx

@@ -11,19 +11,27 @@ const invoke = (fnOrObj, ...args) => typeof fnOrObj === 'function'
 	? fnOrObj(...args)
 	: fnOrObj;
 
-export const withActions = (getActions) => (Component) => {
-	const _wraps = { getActions, Component };
+export const withActions = (getActions, getDefaultState = {}) => (Component) => {
+	const _wraps = { getActions, getDefaultState, Component };
 
 	// if the component we're wrapping is already wrapped, we don't want
 	// to wrap it further. so, discard its wrapper and rewrap the original
 	// component with the new actions on top
 	if(Component._wraps) {
 		const wrappedGetActions = Component._wraps.getActions;
+		const wrappedGetDefaultState = Component._wraps.getDefaultState;
+
 		Component = Component._wraps.Component;
+
 		getActions = initialState => Object.assign(
 			invoke(wrappedGetActions, initialState),
 			invoke(_wraps.getActions, initialState)
 		);
+
+		getDefaultState = initialState => Object.assign(
+			invoke(wrappedGetDefaultState, initialState),
+			invoke(_wraps.getDefaultState, initialState)
+		);
 	}
 
 	function Enhanced({
@@ -33,11 +41,12 @@ export const withActions = (getActions) => (Component) => {
 		...initialState
 	}) {
 		const actions = invoke(getActions, initialState);
+		const defaultState = invoke(getDefaultState, initialState);
 
 		return <Interaction {...{
 			id,
 			Component,
-			initialState,
+			initialState: Object.assign({}, defaultState, initialState),
 			actionsRef,
 			serialiser,
 			actions,