require("../env");

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

var vows = require("vows"),

    assert = require("assert");

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

suite.addBatch({

  "dispatch": {

    topic: function() {

      return d3.dispatch;

    },

    "returns a map of dispatchers for each event type": function(dispatch) {

      assert.deepEqual(dispatch(), {});

      var d = dispatch("foo");

      assert.isTrue("foo" in d);

      assert.isFalse("bar" in d);

      var d = dispatch("foo", "bar");

      assert.isTrue("foo" in d);

      assert.isTrue("bar" in d);

    },

    "added listeners receive subsequent events": function(dispatch) {

      var d = dispatch("foo"), events = 0;

      d.on("foo", function() { ++events; });

      d.foo();

      assert.equal(events, 1);

      d.foo();

      d.foo();

      assert.equal(events, 3);

    },

    "the listener is passed any arguments to dispatch": function(dispatch) {

      var d = dispatch("foo"), a = {}, b = {}, aa, bb;

      d.on("foo", function(a, b) { aa = a; bb = b; });

      d.foo(a, b);

      assert.equal(aa, a);

      assert.equal(bb, b);

      d.foo(1, "foo");

      assert.equal(aa, 1);

      assert.equal(bb, "foo");

    },

    "the listener's context is the same as dispatch's": function(dispatch) {

      var d = dispatch("foo"), a = {}, b = {}, that;

      d.on("foo", function() { that = this; });

      d.foo.call(a);

      assert.equal(that, a);

      d.foo.call(b);

      assert.equal(that, b);

    },

    "listeners are notified in the order they are added": function(dispatch) {

      var d = dispatch("foo"), a = {}, b = {}, those = [];

      function A() { those.push(a); }

      function B() { those.push(b); }

      d.on("foo.a", A);

      d.on("foo.b", B);

      d.foo();

      assert.deepEqual(those, [a, b]);

      those = [];

      d.on("foo.a", A); // move to the end

      d.foo();

      assert.deepEqual(those, [b, a]);

    },

    "removed listeners do not receive subsequent events": function(dispatch) {

      var d = dispatch("foo"), a = {}, b = {}, those = [];

      function A() { those.push(a); }

      function B() { those.push(b); }

      d.on("foo.a", A);

      d.on("foo.b", B);

      d.foo();

      those = [];

      d.on("foo.a", null);

      d.foo();

      assert.deepEqual(those, [b]);

    },

    "adding an existing listener has no effect": function(dispatch) {

      var d = dispatch("foo"), events = 0;

      function A() { ++events; }

      d.on("foo.a", A);

      d.foo();

      d.on("foo.a", A);

      d.on("foo.a", A);

      d.foo();

      assert.equal(events, 2);

    },

    "removing a missing listener has no effect": function(dispatch) {

      var d = dispatch("foo"), events = 0;

      function A() { ++events; }

      d.on("foo.a", null);

      d.on("foo", A);

      d.on("foo", null);

      d.on("foo", null);

      d.foo();

      assert.equal(events, 0);

    },

    "adding a listener does not affect the current event": function(dispatch) {

      var d = dispatch("foo"), a = {}, b = {}, those = [];

      function A() { d.on("foo.b", B); those.push(a); }

      function B() { those.push(b); }

      d.on("foo.a", A);

      d.foo();

      assert.deepEqual(those, [a]);

    },

    "removing a listener does affect the current event": function(dispatch) {

      var d = dispatch("foo"), a = {}, b = {}, those = [];

      function A() { d.on("foo.b", null); those.push(a); }

      function B() { those.push(b); }

      d.on("foo.a", A);

      d.on("foo.b", B);

      d.foo();

      assert.deepEqual(those, [a]);

    }

  }

});

suite.export(module);