Logger for redux

Install

npm i --save redux-logger

Usage

import thunk from 'redux-thunk';
import promise from 'redux-promise';
import createLogger from 'redux-logger';

const logger = createLogger();
const createStoreWithMiddleware = applyMiddleware(thunk, promise, logger)(createStore);
const store = createStoreWithMiddleware(reducer);

Logger must be last middleware in chain, otherwise it will log thunk and promise, not actual actions (#20).

API

redux-logger exposes single constructor function for creating logger middleware.

createLogger(options?: Object)

Options

level (String)

Level of console. warn, error, info or else.

Default: log

logger (Object)

Implementation of the console API. Useful if you are using a custom, wrapped version of console.

Default: window.console

collapsed (getState: Function, action: Object): boolean

Takes a boolean or optionally a function that receives getState function for accessing current store state and action object as parameters. Returns true if the log group should be collapsed, false otherwise.

Default: false

predicate (getState: Function, action: Object): boolean

If specified this function will be called before each action is processed with this middleware. Receives getState function for accessing current store state and action object as parameters. Returns true if action should be logged, false otherwise.

Default: null (always log)

duration (Boolean)

Print duration of each action?

Default: false

timestamp (Boolean)

Print timestamp with each action?

Default: true

transformer (Function)

Transform state before print. Eg. convert Immutable object to plain JSON.

Default: identity function

actionTransformer (Function)

Transform action before print. Eg. convert Immutable object to plain JSON.

Default: identity function

Examples:

log only in dev mode

const __DEV__ = true;

createLogger({
  predicate: (getState, action) => __DEV__
});

log everything except actions with type AUTH_REMOVE_TOKEN

createLogger({
  predicate: (getState, action) => action.type !== AUTH_REMOVE_TOKEN
});

collapse all actions

createLogger({
  collapsed: true
});

collapse actions with type FORM_CHANGE

createLogger({
  collapsed: (getState, action) => action.type === FORM_CHANGE
});

transform Immutable objects into JSON

createLogger({
  transformer: (state) => {
    var newState = {};
    for (var i of Object.keys(state)) {
      if (Immutable.Iterable.isIterable(state[i])) {
        newState[i] = state[i].toJS();
      } else {
        newState[i] = state[i];
      }
    };
    return newState;
  }
});

License

MIT