var includes = require('array-includes');
var assert = require('assert');
var arr = [ 'one', 'two' ];
 
includes(arr, 'one'); // true
includes(arr, 'three'); // false
includes(arr, 'one', 1); // false

var arr = [
    1,
    'foo',
    NaN,
    -0
];
 
assert.equal(arr.indexOf(0) > -1, true);
assert.equal(arr.indexOf(-0) > -1, true);
assert.equal(includes(arr, 0), true);
assert.equal(includes(arr, -0), true);
 
assert.equal(arr.indexOf(NaN) > -1, false);
assert.equal(includes(arr, NaN), true);
 
assert.equal(includes(arr, 'foo', 0), true);
assert.equal(includes(arr, 'foo', 1), true);
assert.equal(includes(arr, 'foo', 2), false);

/* when Array#includes is not present */
delete Array.prototype.includes;
var shimmedIncludes = includes.shim();
 
assert.equal(shimmedIncludes, includes.getPolyfill());
assert.equal(arr.includes('foo', 1), includes(arr, 'foo', 1));

/* when Array#includes is present */
var shimmedIncludes = includes.shim();
 
assert.equal(shimmedIncludes, Array.prototype.includes);
assert.equal(arr.includes(1, 'foo'), includes(arr, 1, 'foo'));