1 files changed, 112 insertions, 0 deletions
diff --git a/addon-sdk/source/test/event/helpers.js b/addon-sdk/source/test/event/helpers.js
new file mode 100644
index 000000000..d0d63d46f
--- /dev/null
+++ b/addon-sdk/source/test/event/helpers.js
@@ -0,0 +1,112 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+const { on, once, off, emit, count } = require("sdk/event/core");
+
+const { setImmediate, setTimeout } = require("sdk/timers");
+const { defer } = require("sdk/core/promise");
+
+/**
+ * Utility function that returns a promise once the specified event's `type`
+ * is emitted on the given `target`, or the delay specified is passed.
+ *
+ * @param {Object|Number} [target]
+ *    The delay to wait, or the object that receives the event.
+ *    If not given, the function returns a promise that will be resolved
+ *    as soon as possible.
+ * @param {String} [type]
+ *    A string representing the event type to waiting for.
+ * @param {Boolean} [capture]
+ *    If `true`, `capture` indicates that the user wishes to initiate capture.
+ *
+ * @returns {Promise}
+ *    A promise resolved once the delay given is passed, or the object
+ *    receives the event specified
+ */
+const wait = function(target, type, capture) {
+  let { promise, resolve, reject } = defer();
+
+  if (!arguments.length) {
+    setImmediate(resolve);
+  }
+  else if (typeof(target) === "number") {
+    setTimeout(resolve, target);
+  }
+  else if (typeof(target.once) === "function") {
+    target.once(type, resolve);
+  }
+  else if (typeof(target.addEventListener) === "function") {
+    target.addEventListener(type, function listener(...args) {
+      this.removeEventListener(type, listener, capture);
+      resolve(...args);
+    }, capture);
+  }
+  else if (typeof(target) === "object" && target !== null) {
+    once(target, type, resolve);
+  }
+  else {
+    reject('Invalid target given.');
+  }
+
+  return promise;
+};
+exports.wait = wait;
+
+function scenario(setup) {
+  return function(unit) {
+    return function(assert) {
+      let actual = [];
+      let input = {};
+      unit(input, function(output, events, expected, message) {
+        let result = setup(output, expected, actual);
+
+        events.forEach(event => emit(input, "data", event));
+
+        assert.deepEqual(actual, result, message);
+      });
+    }
+  }
+}
+
+exports.emits = scenario(function(output, expected, actual) {
+  on(output, "data", function(data) {
+    return actual.push(this, data);
+  });
+
+  return expected.reduce(($$, $) => $$.concat(output, $), []);
+});
+
+exports.registerOnce = scenario(function(output, expected, actual) {
+  function listener(data) {
+    return actual.push(data);
+  }
+  on(output, "data", listener);
+  on(output, "data", listener);
+  on(output, "data", listener);
+
+  return expected;
+});
+
+exports.ignoreNew = scenario(function(output, expected, actual) {
+  on(output, "data", function(data) {
+    actual.push(data + "#1");
+    on(output, "data", function(data) {
+      actual.push(data + "#2");
+    });
+  });
+
+  return expected.map($ => $ + "#1");
+});
+
+exports.FIFO = scenario(function(target, expected, actual) {
+  on(target, "data", $ => actual.push($ + "#1"));
+  on(target, "data", $ => actual.push($ + "#2"));
+  on(target, "data", $ => actual.push($ + "#3"));
+
+  return expected.reduce(function(result, value) {
+    return result.concat(value + "#1", value + "#2", value + "#3");
+  }, []);
+});