v3.0.0

New Features

Performance improvements (thanks to @johnhaley81)
Updated Typescript typings (thanks to everyone who helped)

Breaking Changes

For performance reasons, a selector is now not recalculated if its input is equal by reference (===).

Example:

import { createSelector } from 'reselect';

const mySelector = createSelector(
  state => state.values.filter(val => val < 5),
  values => {
    console.log('calling..')
    return values.reduce((acc, val) => acc + val, 0)
  }
)

var createSelector = require('./dist/reselect.js').createSelector;

const mySelector = createSelector(
  state => state.values.filter(val => val < 5),
  values => {
    console.log('calling..')
    return values.reduce((acc, val) => acc + val, 0)
  }
)

var state1 = {values: [1,2,3,4,5,6,7,8,9]};
console.log(mySelector(state1));
state1.values = [3,4,5,6,7,8,9];
console.log(mySelector(state1));
var state2 = {values: [1,2,3,4,5,6,7,8,9]};
console.log(mySelector(state2));
var state3 = {values: [3,4,5,6,7]};
console.log(mySelector(state3));

Output in v2.5.4:

calling..
10
calling..
7
calling..
10
calling..
7

Output in v3.0.0:

calling..
10
10
calling..
10
calling..
7