FIX: Avoid race conditions when toggling presence state (#19648)

We need to set the local state of a channel before performing any async operations. Otherwise, multiple leave/join calls can race against each other and cause the local state to get out-of-sync with the server.

Followup to e70ed31a
This commit is contained in:
David Taylor 2022-12-29 00:44:31 +00:00 committed by GitHub
parent 083ef4c8a1
commit 25ad99637d
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2 changed files with 53 additions and 5 deletions

View File

@ -67,16 +67,16 @@ class PresenceChannel extends EmberObject.extend(Evented) {
this.setProperties({ activeOptions });
if (!this.present) {
await this.presenceService._enter(this);
this.set("present", true);
await this.presenceService._enter(this);
}
}
// Mark the current user as leaving this channel
async leave() {
if (this.present) {
await this.presenceService._leave(this);
this.set("present", false);
await this.presenceService._leave(this);
}
}

View File

@ -32,7 +32,7 @@ function usersFixture() {
acceptance("Presence - Subscribing", function (needs) {
needs.pretender((server, helper) => {
server.get("/presence/get", (request) => {
server.get("/presence/get", async (request) => {
const channels = request.queryParams.channels;
const response = {};
@ -245,10 +245,29 @@ acceptance("Presence - Subscribing", function (needs) {
acceptance("Presence - Entering and Leaving", function (needs) {
needs.user();
let responseStartPromise;
let resolveResponseStartPromise;
let responseWaitPromise;
const requests = [];
needs.hooks.afterEach(() => requests.clear());
needs.hooks.beforeEach(() => {
responseStartPromise = new Promise(
(resolve) => (resolveResponseStartPromise = resolve)
);
});
needs.hooks.afterEach(() => {
requests.clear();
responseWaitPromise = null;
responseStartPromise = null;
});
needs.pretender((server, helper) => {
server.post("/presence/update", (request) => {
server.post("/presence/update", async (request) => {
resolveResponseStartPromise();
await responseWaitPromise;
const body = new URLSearchParams(request.requestBody);
requests.push(body);
@ -325,6 +344,35 @@ acceptance("Presence - Entering and Leaving", function (needs) {
);
});
test("interleaved join/leave calls work correctly", async function (assert) {
let resolveServerResponse;
responseWaitPromise = new Promise(
(resolve) => (resolveServerResponse = resolve)
);
const presenceService = this.container.lookup("service:presence");
const channel = presenceService.getChannel("/test/ch1");
const enterPromise = channel.enter();
await responseStartPromise;
const leavePromise = channel.leave();
resolveServerResponse();
await enterPromise;
await leavePromise;
assert.strictEqual(requests.length, 2, "server received two requests");
const presentChannels = requests.map((r) => r.getAll("present_channels[]"));
const leaveChannels = requests.map((r) => r.getAll("leave_channels[]"));
assert.deepEqual(presentChannels, [["/test/ch1"], []]);
assert.deepEqual(leaveChannels, [[], ["/test/ch1"]]);
});
test("raises an error when entering a non-existent channel", async function (assert) {
const presenceService = this.container.lookup("service:presence");
const channel = presenceService.getChannel("/blah/does-not-exist");