devtools/shared/tests/mochitest/test_eventemitter_basic.html
author Paolo Amadini <paolo.mozmail@amadzone.org>
Mon, 19 Jun 2017 11:32:37 +0100
changeset 416020 1075b94a522dbadf874f224312fa542d3fecdc9d
parent 393926 a072d7934ff7c6fd2ad974d7abc0b08d11041aca
child 426158 58f678547059f27e2dd930b7c9fa4b7bf44365e2
permissions -rw-r--r--
Bug 1362970 - Part 2 - Script-generated patch to convert .then(null, ...) to .catch(...). r=florian Changes to Promise tests designed to test .then(null) have been reverted, and the browser/extensions directory was excluded because the projects it contains have a separate process for accepting changes. MozReview-Commit-ID: 1buqgX1EP4P

<!DOCTYPE html>
<!--
  Any copyright is dedicated to the Public Domain.
  http://creativecommons.org/publicdomain/zero/1.0/
-->

<html>

  <head>
    <meta charset="utf8">
    <title></title>

    <script type="application/javascript"
            src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
    <link rel="stylesheet" type="text/css"
          href="chrome://mochikit/content/tests/SimpleTest/test.css">
  </head>

  <body>

    <script type="application/javascript">
      "use strict";

      const { utils: Cu } = Components;
      const { require } = Cu.import("resource://devtools/shared/Loader.jsm", {});
      const promise = require("promise");
      const EventEmitter = require("devtools/shared/event-emitter");
      const { Task } = require("devtools/shared/task");

      SimpleTest.waitForExplicitFinish();

      testEmitter();
      testEmitter({});

      Task.spawn(testPromise)
          .catch(ok.bind(null, false))
          .then(SimpleTest.finish);

      function testEmitter(aObject) {
        let emitter;

        if (aObject) {
          emitter = aObject;
          EventEmitter.decorate(emitter);
        } else {
          emitter = new EventEmitter();
        }

        ok(emitter, "We have an event emitter");

        let beenHere1 = false;
        let beenHere2 = false;

        emitter.on("next", next);
        emitter.emit("next", "abc", "def");

        function next(eventName, str1, str2) {
          is(eventName, "next", "Got event");
          is(str1, "abc", "Argument 1 is correct");
          is(str2, "def", "Argument 2 is correct");

          ok(!beenHere1, "first time in next callback");
          beenHere1 = true;

          emitter.off("next", next);

          emitter.emit("next");

          emitter.once("onlyonce", onlyOnce);

          emitter.emit("onlyonce");
          emitter.emit("onlyonce");
        }

        function onlyOnce() {
          ok(!beenHere2, "\"once\" listener has been called once");
          beenHere2 = true;
          emitter.emit("onlyonce");

          testThrowingExceptionInListener();
        }

        function testThrowingExceptionInListener() {
          function throwListener() {
            emitter.off("throw-exception");
            throw {
              toString: () => "foo",
              stack: "bar",
            };
          }

          emitter.on("throw-exception", throwListener);
          emitter.emit("throw-exception");

          killItWhileEmitting();
        }

        function killItWhileEmitting() {
          function c1() {
            ok(true, "c1 called");
          }
          function c2() {
            ok(true, "c2 called");
            emitter.off("tick", c3);
          }
          function c3() {
            ok(false, "c3 should not be called");
          }
          function c4() {
            ok(true, "c4 called");
          }

          emitter.on("tick", c1);
          emitter.on("tick", c2);
          emitter.on("tick", c3);
          emitter.on("tick", c4);

          emitter.emit("tick");

          offAfterOnce();
        }

        function offAfterOnce() {
          let enteredC1 = false;

          function c1() {
            enteredC1 = true;
          }

          emitter.once("oao", c1);
          emitter.off("oao", c1);

          emitter.emit("oao");

          ok(!enteredC1, "c1 should not be called");
        }
      }

      function testPromise() {
        let emitter = new EventEmitter();
        let p = emitter.once("thing");

        // Check that the promise is only resolved once event though we
        // emit("thing") more than once
        let firstCallbackCalled = false;
        let check1 = p.then(arg => {
          is(firstCallbackCalled, false, "first callback called only once");
          firstCallbackCalled = true;
          is(arg, "happened", "correct arg in promise");
          return "rval from c1";
        });

        emitter.emit("thing", "happened", "ignored");

        // Check that the promise is resolved asynchronously
        let secondCallbackCalled = false;
        let check2 = p.then(arg => {
          ok(true, "second callback called");
          is(arg, "happened", "correct arg in promise");
          secondCallbackCalled = true;
          is(arg, "happened", "correct arg in promise (a second time)");
          return "rval from c2";
        });

        // Shouldn't call any of the above listeners
        emitter.emit("thing", "trashinate");

        // Check that we can still separate events with different names
        // and that it works with no parameters
        let pfoo = emitter.once("foo");
        let pbar = emitter.once("bar");

        let check3 = pfoo.then(arg => {
          ok(arg === undefined, "no arg for foo event");
          return "rval from c3";
        });

        pbar.then(() => {
          ok(false, "pbar should not be called");
        });

        emitter.emit("foo");

        is(secondCallbackCalled, false, "second callback not called yet");

        return promise.all([ check1, check2, check3 ]).then(args => {
          is(args[0], "rval from c1", "callback 1 done good");
          is(args[1], "rval from c2", "callback 2 done good");
          is(args[2], "rval from c3", "callback 3 done good");
        });
      }
    </script>
  </body>
</html>