require("../env");

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

var assert = require("assert");

module.exports = {

  topic: function() {

    return d3.select("body").html("").selectAll()

        .data(["foo", "bar"])

      .enter().append("div")

        .attr("class", String);

  },

  "defaults to 250 milliseconds": function(selection) {

    var t = selection.transition();

    assert.strictEqual(t[0][0].duration, 250);

    assert.strictEqual(t[0][1].duration, 250);

  },

  "can specify duration as a number": function(selection) {

    var t = selection.transition().duration(150);

    assert.strictEqual(t[0][0].duration, 150);

    assert.strictEqual(t[0][1].duration, 150);

    t.duration(50);

    assert.strictEqual(t[0][0].duration, 50);

    assert.strictEqual(t[0][1].duration, 50);

  },

  "can specify duration as a function": function(selection) {

    var dd = [], ii = [], tt = [], t = selection.transition().duration(f);

    function f(d, i) { dd.push(d); ii.push(i); tt.push(this); return i * 20; }

    assert.strictEqual(t[0][0].duration, 0);

    assert.strictEqual(t[0][1].duration, 20);

    assert.deepEqual(dd, ["foo", "bar"], "expected data, got {actual}");

    assert.deepEqual(ii, [0, 1], "expected index, got {actual}");

    assert.domEqual(tt[0], t[0][0].node, "expected this, got {actual}");

    assert.domEqual(tt[1], t[0][1].node, "expected this, got {actual}");

  },

  "coerces duration to a number": function(selection) {

    var t = selection.transition().duration("150");

    assert.strictEqual(t[0][0].duration, 150);

    assert.strictEqual(t[0][1].duration, 150);

  }

};