vuex-mock-context

Test mock for vuex context

Install

npm install vuex-mock-context -D

Why

For testing that vuex actions commit mutations and dispatch actions as expected.
See Composing Actions in the Vuex docs.

Usage

You have this vuex action

save(context, payload) {
  context.commit('INCREMENT_SAVE_COUNT');
  return context.dispatch('update', payload);
}

You can test it like this

import {create} from 'vuex-mock-context';
import actions from './actions';

test('save action increments count and then updates', function() {
  // set up mock context
  const context = create();

  // invoke action handler
  return actions.save(context, {value: 'whatever'})
    .then(() => {
      // verify context interactions
      assert.deepEquals(context.log, [
        {mutation: ['INCREMENT_SAVE_COUNT']},
        {action: ['update', {value: 'whatever'}]}
      ]);
    });
});

Snapshot testing

If you are using Jest or some other framework that supports snapshot testing, capture and verify context.log with a snapshot:

expect(context.log).toMatchSnapshot();

API

import {create} from 'vuex-mock-context';

const mockContext = create(actionHandler)

Create a mock context.
actionHandler is an optional function that receives all parameters sent to dispatch() and returns a Promise which will be the return value of dispatch(). Defaults to function that returns a resolved Promise with undefined value.

mockContext.commit()

Just like context.commit() in vuex.

mockContext.dispatch()

Just like context.dispatch() in vuex.
Return value is determined by actionHandler, see above.

mockContext.log

Array of objects that represent context interactions. There are two types of interactions:

1. mutation

{mutation: [<args passed to commit>]}

For example

context.commit('DO_SOMETHING', {value: 1});

becomes

{mutation: ['DO_SOMETHING', {value: 1}]}

1. action

{action: [<args passed to dispatch>]}

For example

context.dispatch('save', {id: 5});

becomes

{action: ['save', {id: 5}]}

mockContext.state

mockContext.getters

mockContext.rootState

mockContext.rootGetters

All of these start off as an empty object. You can add properties as needed.

License

MIT