atom/test/reducer.js

shared, synchronous, independent state for javascript apps

"use strict";

var atom = require("../");
var test = require("tape");

var genericAction = { a: 1 };

test("atom should accept a single reducer", function (t) {
  t.plan(1);

  var called = false;
  var singleReducer = function () {
    called = true;
    return called;
  };
  var store = atom(singleReducer, 0);

  store.dispatch(genericAction);

  t.ok(called);
});

test("atom should accept an array of reducers", function (t) {
  t.plan(1);

  var store = atom(
    [
      function (_, state) {
        return state + 2;
      },
      function (_, state) {
        return state * state;
      },
      function (_, state) {
        return "" + state;
      },
    ],
    0,
  );

  store.dispatch(genericAction);

  t.equal(store.getState(), "4");
});

test("atom should handle an async reducer", function (t) {
  t.plan(1);

  var calls = 0;
  var store = atom(
    [
      function (_, state) {
        return state + 1;
      },
      function (_, state) {
        return function (dispatch) {
          if (calls) return;
          setTimeout(function () {
            dispatch(genericAction);
          }, 1000);
        };
      },
      function (_, state) {
        return state + 1;
      },
    ],
    0,
  );

  store.subscribe(function () {
    calls++;
    if (calls === 2) {
      t.equal(store.getState(), 4);
    }
  });

  store.dispatch(genericAction);
});