1 require("../env");

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

     3 

     4 var assert = require("assert");

     5 

     6 module.exports = {

     7   topic: function() {

     8     var cb = this.callback,

     9         dd = [],

    10         ii = [],

    11         tt = [],

    12         vv = [];

    13 

    14     var s = d3.select("body").html("").append("div").selectAll("div")

    15         .data(["red", "green"])

    16       .enter().append("div")

    17         .attr("color", function(d) { return d3.rgb(d)+""; });

    18 

    19     var t = s.transition()

    20         .attrTween("color", tween);

    21 

    22     function tween(d, i, v) {

    23       dd.push(d);

    24       ii.push(i);

    25       vv.push(v);

    26       if (tt.push(this) >= 2) cb(null, {

    27         selection: s,

    28         transition: t,

    29         data: dd,

    30         index: ii,

    31         value: vv,

    32         context: tt

    33       });

    34       return i && d3.interpolateHsl(v, "blue");

    35     }

    36   },

    37 

    38   // The order here is a bit brittle: because the transition has zero delay,

    39   // it's invoking the start event immediately for all nodes, rather than

    40   // pushing each node onto the timer queue (which would reverse the order of

    41   // callbacks). The order in which tweens are invoked is undefined, so perhaps

    42   // we should sort the expected and actual values before comparing.

    43 

    44   "defines the corresponding attr tween": function(result) {

    45     assert.typeOf(result.transition.tween("attr.color"), "function");

    46   },

    47   "invokes the tween function": function(result) {

    48     assert.deepEqual(result.data, ["red", "green"], "expected data, got {actual}");

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

    50     assert.deepEqual(result.value, ["#ff0000", "#008000"], "expected value, got {actual}");

    51     assert.domEqual(result.context[0], result.selection[0][0], "expected this, got {actual}");

    52     assert.domEqual(result.context[1], result.selection[0][1], "expected this, got {actual}");

    53   },

    54 

    55   "end": {

    56     topic: function(result) {

    57       var cb = this.callback;

    58       result.transition.each("end", function(d, i) { if (i >= 1) cb(null, result); });

    59     },

    60     "uses the returned interpolator": function(result) {

    61       assert.equal(result.selection[0][1].getAttribute("color"), "#0000ff");

    62     },

    63     "does nothing if the interpolator is falsey": function(result) {

    64       assert.equal(result.selection[0][0].getAttribute("color"), "#ff0000");

    65     }

    66   }

    67 };