redux-css.js

import { isObjLiteral } from './utils/helpers';
// import { objectMapReducer } from './utils/reducerGenerators'
import {
  setVariable,
  setAllVariables,
  getVariable,
  getAllVariables,
  removeVariable,
  removeAllVaraibles,
} from './utils/css';

const buildReducer = reducer => {
  let formattedReducer;
  formattedReducer = reducer;
  return formattedReducer;
};

const middleware = (reducer, currentVars, action, state) => {
  const nextVars = reducer(currentVars, action, state);
  if (nextVars !== currentVars) {
    new Set([...Object.keys(currentVars), ...Object.keys(nextVars)]).forEach(varName => {
      if (currentVars[varName] !== nextVars[varName]) {
        const value = nextVars[varName];
        if (value !== undefined) {
          setVariable(varName, value);
          currentVars[varName] = value;
        } else {
          removeVariable(varName);
          delete currentVars[varName];
        }
      }
    });
  }
};

export default (initialReducer, initialVars) => {
  let reducer = buildReducer(initialReducer);

  const currentVars = Object.assign(
    {},
    initialVars,
    reducer(initialVars, {
      type: '@@CSS-REDUX/init',
    }),
  );

  setAllVariables(currentVars);

  return {
    middleware: store => next => action => {
      middleware(reducer, currentVars, action, store.getState());
      return next(action);
    },
    replaceReducer: nextReducer => {
      reducer = buildReducer(nextReducer);
    },
    setVariable: (varName, value) => {
      const prevValue = currentVars[varName];
      if (prevValue !== value) {
        setVariable(varName, value);
        currentVars[varName] = value;
      }
      return prevValue;
    },
    setAllVariables: (vars = {}) => {
      for (const varName in vars) {
        const prevValue = currentVars[varName];
        if (prevValue !== vars[varName]) {
          setVariable(varName, vars[varName]);
          currentVars[varName] = vars[varName];
        }
      }
    },
    getVariable: varName => currentVars[varName],
    getAllVariables: () => Object.assign({}, currentVars),
    removeVariable: varName => {
      if (currentVars[varName]) {
        removeVariable(varName);
        delete currentVars[varName];
      }
    },
  };
};