Bug 1066619 - Accept Promise arguments in PromiseWorker. r=froydnj

toolkit/components/promiseworker/PromiseWorker.jsm

@@ -242,9 +242,10 @@ this.BasePromiseWorker.prototype = {
    * Post a message to a worker.
    *
    * @param {string} fun The name of the function to call.
-   * @param {Array} args The arguments to pass to `fun`. By convention,
-   * the last argument may be an object `options` with some of the following
-   * fields:
+   * @param {Array} args The arguments to pass to `fun`. If any
+   * of the arguments is a Promise, it is resolved before posting the
+   * message. By convention, the last argument may be an object `options`
+   * with some of the following fields:
    * - {number|null} outExecutionDuration A parameter to be filled with the
    *   duration of the off main thread execution for this call.
    * @param {*=} closure An object holding references that should not be
@@ -254,6 +255,11 @@ this.BasePromiseWorker.prototype = {
    */
   post: function(fun, args, closure) {
     return Task.spawn(function* postMessage() {
+      // Normalize in case any of the arguments is a promise
+      if (args) {
+        args = yield Promise.resolve(Promise.all(args));
+      }
+
       let id = ++this._id;
       let message = {fun: fun, args: args, id: id};
       this.log("Posting message", message);

toolkit/components/promiseworker/moz.build

@@ -11,3 +11,5 @@ DIRS += [
 EXTRA_JS_MODULES += [
     'PromiseWorker.jsm',
 ]
+
+XPCSHELL_TESTS_MANIFESTS += ['tests/xpcshell/xpcshell.ini']

toolkit/components/promiseworker/tests/xpcshell/data/chrome.manifest

@@ -0,0 +1 @@
+content promiseworker ./

toolkit/components/promiseworker/tests/xpcshell/data/worker.js

@@ -0,0 +1,30 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Trivial worker definition
+
+importScripts("resource://gre/modules/workers/require.js");
+let PromiseWorker = require("resource://gre/modules/workers/PromiseWorker.js");
+
+let worker = new PromiseWorker.AbstractWorker();
+worker.dispatch = function(method, args = []) {
+  return Agent[method](...args);
+},
+worker.postMessage = function(...args) {
+  self.postMessage(...args);
+};
+worker.close = function() {
+  self.close();
+};
+worker.log = function(...args) {
+  dump("Worker: " + args.join(" ") + "\n");
+};
+self.addEventListener("message", msg => worker.handleMessage(msg));
+
+let Agent = {
+  bounce: function(...args) {
+    return args;
+  }
+};

toolkit/components/promiseworker/tests/xpcshell/test_Promise.js

@@ -0,0 +1,65 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+let Cu = Components.utils;
+
+Cu.import("resource://gre/modules/PromiseWorker.jsm", this);
+Cu.import("resource://gre/modules/Timer.jsm", this);
+
+// Worker must be loaded from a chrome:// uri, not a file://
+// uri, so we first need to load it.
+
+let WORKER_SOURCE_URI = "chrome://promiseworker/content/worker.js";
+do_load_manifest("data/chrome.manifest");
+let worker = new BasePromiseWorker(WORKER_SOURCE_URI);
+worker.log = function(...args) {
+  do_print("Controller: " + args.join(" "));
+};
+
+// Test that simple messages work
+add_task(function* test_simple_args() {
+  let message = ["test_simple_args", Math.random()];
+  let result = yield worker.post("bounce", message);
+  Assert.equal(JSON.stringify(result), JSON.stringify(message));
+});
+
+// Test that it works when we don't provide a message
+add_task(function* test_no_args() {
+  let result = yield worker.post("bounce");
+  Assert.equal(JSON.stringify(result), JSON.stringify([]));
+});
+
+// Test that messages with promise work
+add_task(function* test_promise_args() {
+  let message = ["test_promise_args", Promise.resolve(Math.random())];
+  let stringified = JSON.stringify((yield Promise.resolve(Promise.all(message))));
+  let result = yield worker.post("bounce", message);
+  Assert.equal(JSON.stringify(result), stringified);
+});
+
+// Test that messages with delayed promise work
+add_task(function* test_delayed_promise_args() {
+  let promise = new Promise(resolve => setTimeout(() => resolve(Math.random()), 10));
+  let message = ["test_delayed_promise_args", promise];
+  let stringified = JSON.stringify((yield Promise.resolve(Promise.all(message))));
+  let result = yield worker.post("bounce", message);
+  Assert.equal(JSON.stringify(result), stringified);
+});
+
+// Test that messages with rejected promise cause appropriate errors
+add_task(function* test_rejected_promise_args() {
+  let error = new Error();
+  let message = ["test_promise_args", Promise.reject(error)];
+  try {
+    yield worker.post("bounce", message);
+    do_throw("I shound have thrown an error by now");
+  } catch (ex if ex == error) {
+    do_print("I threw the right error");
+  }
+});
+
+function run_test() {
+  run_next_test();
+}

toolkit/components/promiseworker/tests/xpcshell/xpcshell.ini

@@ -0,0 +1,8 @@
+[DEFAULT]
+head=
+tail=
+support-files=
+  data/worker.js
+  data/chrome.manifest
+
+[test_Promise.js]