require("../env");

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

var vows = require("vows"),

    assert = require("assert");

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

suite.addBatch({

  "range": {

    topic: function() {

      return d3.range;

    },

    "start is an inclusive lower bound": function(range) {

      assert.equal(range(5)[0], 0);

      assert.equal(range(1, 5)[0], 1);

      assert.equal(range(5, 1, -1)[0], 5);

    },

    "stop is an exclusive upper bound": function(range) {

      assert.equal(range(5)[4], 4);

      assert.equal(range(1, 5)[3], 4);

      assert.equal(range(5, 1, -1)[3], 2);

    },

    "with one argument, returns integers [0 … stop)": function(range) {

      assert.deepEqual(range(0), []);

      assert.deepEqual(range(1), [0]);

      assert.deepEqual(range(5), [0, 1, 2, 3, 4]);

    },

    "with two arguments, returns integers [start … stop)": function(range) {

      assert.deepEqual(range(0, 5), [0, 1, 2, 3, 4]);

      assert.deepEqual(range(5, 9), [5, 6, 7, 8]);

    },

    "with three arguments, returns start + k * step": function(range) {

      assert.deepEqual(range(0, 5, 1), [0, 1, 2, 3, 4]);

      assert.deepEqual(range(5, 9, .5), [5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5]);

      assert.deepEqual(range(5, 8.5, .5), [5, 5.5, 6, 6.5, 7, 7.5, 8]);

      assert.deepEqual(range(2, 0, -.5), [2, 1.5, 1, .5]);

    },

    "returns an ascending range if step is positive": function(range) {

      assert.deepEqual(range(0, 5, 1), [0, 1, 2, 3, 4]);

    },

    "returns a descending range if step is negative": function(range) {

      assert.deepEqual(range(5, 0, -1), [5, 4, 3, 2, 1]);

    },

    "returns an empty range if start, stop or step are NaN": function(range) {

      assert.isEmpty(range(0, NaN));

      assert.isEmpty(range(1, NaN));

      assert.isEmpty(range(-1, NaN));

      assert.isEmpty(range(0, undefined));

      assert.isEmpty(range(1, undefined));

      assert.isEmpty(range(-1, undefined));

      assert.isEmpty(range(NaN, 0));

      assert.isEmpty(range(NaN, 1));

      assert.isEmpty(range(NaN, -1));

      assert.isEmpty(range(undefined, 0));

      assert.isEmpty(range(undefined, 1));

      assert.isEmpty(range(undefined, -1));

      assert.isEmpty(range(NaN, NaN));

      assert.isEmpty(range(undefined, undefined));

      assert.isEmpty(range(NaN, NaN, NaN));

      assert.isEmpty(range(undefined, undefined, undefined));

      assert.isEmpty(range(0, 10, NaN));

      assert.isEmpty(range(10, 0, NaN));

      assert.isEmpty(range(0, 10, undefined));

      assert.isEmpty(range(10, 0, undefined));

    },

    "returns an empty range if start equals stop": function(range) {

      assert.isEmpty(range(10, 10));

      assert.isEmpty(range(10, 10, 1));

      assert.isEmpty(range(10, 10, -1));

      assert.isEmpty(range(10, 10, -.5));

      assert.isEmpty(range(10, 10, .5));

      assert.isEmpty(range(0, 0));

      assert.isEmpty(range(0, 0, 1));

      assert.isEmpty(range(0, 0, -1));

      assert.isEmpty(range(0, 0, -.5));

      assert.isEmpty(range(0, 0, .5));

    },

    "returns an empty range if stop is less than start and step is positive": function(range) {

      assert.isEmpty(range(20, 10));

      assert.isEmpty(range(20, 10, 2));

      assert.isEmpty(range(20, 10, 1));

      assert.isEmpty(range(20, 10, .5));

    },

    "returns an empty range if stop is greater than start and step is negative": function(range) {

      assert.isEmpty(range(10, 20, -2));

      assert.isEmpty(range(10, 20, -1));

      assert.isEmpty(range(10, 20, -.5));

    }

  }

});

suite.export(module);