Add test for dispatch.

test/core/dispatch-test.js

@@ -0,0 +1,116 @@
+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.foo.add(function() { ++events; });
+      d.foo.dispatch();
+      assert.equal(events, 1);
+      d.foo.dispatch();
+      d.foo.dispatch();
+      assert.equal(events, 3);
+    },
+    "the listener is passed any arguments to dispatch": function(dispatch) {
+      var d = dispatch("foo"), a = {}, b = {}, aa, bb;
+      d.foo.add(function(a, b) { aa = a; bb = b; });
+      d.foo.dispatch(a, b);
+      assert.equal(aa, a);
+      assert.equal(bb, b);
+      d.foo.dispatch(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.foo.add(function() { that = this; });
+      d.foo.dispatch.call(a);
+      assert.equal(that, a);
+      d.foo.dispatch.call(b);
+      assert.equal(that, b);
+    },
+    "listeners are notified in the order they are first added": function(dispatch) {
+      var d = dispatch("foo"), a = {}, b = {}, those = [];
+      function A() { those.push(a); }
+      function B() { those.push(b); }
+      d.foo.add(A);
+      d.foo.add(B);
+      d.foo.dispatch();
+      assert.deepEqual(those, [a, b]);
+      those = [];
+      d.foo.remove(A);
+      d.foo.add(A);
+      d.foo.dispatch();
+      assert.deepEqual(those, [a, b]);
+    },
+    "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.foo.add(A);
+      d.foo.add(B);
+      d.foo.dispatch();
+      those = [];
+      d.foo.remove(A);
+      d.foo.dispatch();
+      assert.deepEqual(those, [b]);
+    },
+    "adding an existing listener has no effect": function(dispatch) {
+      var d = dispatch("foo"), events = 0;
+      function A() { ++events; }
+      d.foo.add(A);
+      d.foo.dispatch();
+      d.foo.add(A);
+      d.foo.add(A);
+      d.foo.dispatch();
+      assert.equal(events, 2);
+    },
+    "removing a missing listener has no effect": function(dispatch) {
+      var d = dispatch("foo"), events = 0;
+      function A() { ++events; }
+      d.foo.remove(A);
+      d.foo.add(A);
+      d.foo.remove(A);
+      d.foo.remove(A);
+      d.foo.dispatch();
+      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.foo.add(B); those.push(a); }
+      function B() { those.push(b); }
+      d.foo.add(A);
+      d.foo.dispatch();
+      assert.deepEqual(those, [a]);
+    },
+    "removing a listener does affect the current event": function(dispatch) {
+      var d = dispatch("foo"), a = {}, b = {}, those = [];
+      function A() { d.foo.remove(B); those.push(a); }
+      function B() { those.push(b); }
+      d.foo.add(A);
+      d.foo.add(B);
+      d.foo.dispatch();
+      assert.deepEqual(those, [a]);
+    }
+  }
+});
+
+suite.export(module);