const CHANGE_ERASER_SIZE = 'scratch-paint/tools/CHANGE_ERASER_SIZE'; const initialState = {brushSize: 20}; const reducer = function (state, action) { if (typeof state === 'undefined') state = initialState; switch (action.type) { case CHANGE_ERASER_SIZE: return {brushSize: Math.max(1, action.brushSize)}; default: return state; } }; // Action creators ================================== reducer.changeBrushSize = function (brushSize) { return { type: CHANGE_ERASER_SIZE, brushSize: brushSize, meta: { throttle: 30 } }; }; export default reducer;