--[[
	The stateUpdater accepts props when they update and computes the
	complete set of props that should be passed to the wrapped component.

	Each connected component will have a stateUpdater created for it.

	stateUpdater is put into the component's state in order for
	getDerivedStateFromProps to be able to access it. It is not mutated.
]]

local function makeStateUpdater(store)
	return function(nextProps, prevState, mappedStoreState)
		-- The caller can optionally provide mappedStoreState if it needed that
		-- value beforehand. Doing so is purely an optimization.
		if mappedStoreState == nil then
			mappedStoreState = prevState.mapStateToProps(store:getState(), nextProps)
		end

		local propsForChild = join(nextProps, mappedStoreState, prevState.mappedStoreDispatch)

		return {
			mappedStoreState = mappedStoreState,
			propsForChild = propsForChild,
		}
	end
end
