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var R = require('../source');var eq = require('./shared/eq');

describe('difference', function() {  var M = [1, 2, 3, 4];  var M2 = [1, 2, 3, 4, 1, 2, 3, 4];  var N = [3, 4, 5, 6];  var N2 = [3, 3, 4, 4, 5, 5, 6, 6];  var Z = [3, 4, 5, 6, 10];  var Z2 = [1, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 8];  it('finds the set of all elements in the first list not contained in the second', function() {    eq(R.difference(M, N), [1, 2]);  });
  it('does not allow duplicates in the output even if the input lists had duplicates', function() {    eq(R.difference(M2, N2), [1, 2]);  });
  it('has R.equals semantics', function() {    function Just(x) { this.value = x; }    Just.prototype.equals = function(x) {      return x instanceof Just && R.equals(x.value, this.value);    };
    eq(R.difference([0], [-0]).length, 1);    eq(R.difference([-0], [0]).length, 1);    eq(R.difference([NaN], [NaN]).length, 0);    eq(R.difference([new Just([42])], [new Just([42])]).length, 0);  });
  it('works for arrays of different lengths', function() {    eq(R.difference(Z, Z2), [10]);    eq(R.difference(Z2, Z), [1, 2, 7, 8]);  });
  it('will not create a "sparse" array', function() {    eq(R.difference(M2, [3]).length, 3);  });
  it('returns an empty array if there are no different elements', function() {    eq(R.difference(M2, M), []);    eq(R.difference(M, M2), []);    eq(R.difference([], M2), []);  });
});