1 require("../env");

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

     3 

     4 var vows = require("vows"),

     5     assert = require("assert");

     6 

     7 var suite = vows.describe("d3.timer");

     8 

     9 suite.addBatch({

    10   "timer": {

    11     topic: function() {

    12       return d3.timer;

    13     },

    14     "with no delay": {

    15       topic: timer(),

    16       "first calls after 17 ms or less": function(info) {

    17         assert.inDelta(info.start - info.scheduled, 17, 20);

    18       },

    19       "calls until the function returns true": function(info) {

    20         assert.equal(info.count, 4);

    21       },

    22       "calls every 17 ms": function(info) {

    23         assert.inDelta(info.stop - info.start, 17 * 3, 20);

    24       }

    25     },

    26     "with a specified delay": {

    27       topic: timer(250),

    28       "first calls after the delay": function(info) {

    29         assert.inDelta(info.start - info.scheduled, 250, 20);

    30       },

    31       "calls until the function returns true": function(info) {

    32         assert.equal(info.count, 4);

    33       },

    34       "calls every 17 ms": function(info) {

    35         assert.inDelta(info.stop - info.start, 17 * 3, 20);

    36       }

    37     }

    38   }

    39 });

    40 

    41 function timer(delay) {

    42   var args = Array.prototype.slice.call(arguments);

    43   return function() {

    44     var cb = this.callback,

    45         info = {scheduled: Date.now(), count: 0};

    46 

    47     args.unshift(function() {

    48       var count = ++info.count;

    49       if (count === 1) {

    50         info.start = Date.now();

    51       } else if (count === 4) {

    52         info.stop = Date.now();

    53         cb(null, info);

    54         return true;

    55       }

    56     });

    57 

    58     d3.timer.apply(this, args);

    59   };

    60 }

    61 

    62 suite.export(module);