require("../env");

require("../../d3");

var vows = require("vows"),

    assert = require("assert");

var suite = vows.describe("d3.descending");

suite.addBatch({

  "numbers": {

    "returns a negative number if a > b": function() {

      assert.isTrue(d3.descending(1, 0) < 0);

    },

    "returns a positive number if a < b": function() {

      assert.isTrue(d3.descending(0, 1) > 0);

    },

    "returns zero if a == b": function() {

      assert.equal(d3.descending(0, 0), 0);

    },

    "returns NaN if a or b is undefined": function() {

      assert.isNaN(d3.descending(0, undefined));

      assert.isNaN(d3.descending(undefined, 0));

      assert.isNaN(d3.descending(undefined, undefined));

    },

    "returns NaN if a or b is NaN": function() {

      assert.isNaN(d3.descending(0, NaN));

      assert.isNaN(d3.descending(NaN, 0));

      assert.isNaN(d3.descending(NaN, NaN));

    }

  }

});

suite.addBatch({

  "strings": {

    "returns a negative number if a > b": function() {

      assert.isTrue(d3.descending("b", "a") < 0);

    },

    "returns a positive number if a < b": function() {

      assert.isTrue(d3.descending("a", "b") > 0);

    },

    "returns zero if a == b": function() {

      assert.equal(d3.descending("a", "a"), 0);

    }

  }

});

suite.export(module);