e2e-casebook

A small, realistic web app built to be tested end to end. Each case is a feature that is hard to test well, with a list of requirements. Write automated tests that check every requirement. Each case hides a detail that makes the obvious test miss a broken requirement.

Bring your own framework: Playwright, Cypress, WebdriverIO, or anything that drives a browser.

Live demo: https://e2e-proving-ground.onrender.com (free tier: if it has been idle, it takes about a minute to wake, and it starts empty after every wake).

Worked solutions: solutions/ has Playwright approaches to 12 cases, each scored against bugs planted in the app, plus a benchmark of AI agents writing tests for the same cases. The other cases stay unsolved.

Start here

200+ cases is a lot. These twelve show the range:

Case	Why it is hard to test
1. Two-user realtime chat	Two browsers, a dropped socket, and messages that must arrive once and in order.
3. Optimistic moves	The screen changes before the server answers, and has to change back when it says no.
6. Due dates, time zones, and DST	The bug only shows in some zones, on some dates.
24. Draft	Autosave with retries, and a race you have to make happen.
38. Search	Answers that arrive out of order.
72. Upload	Progress, cancel, and a server that must keep nothing from a broken upload.
95. Local notes	An IndexedDB upgrade while another tab holds the old version open.
104. Concert tickets	A page restored from the back/forward cache, which fires no load.
111. Bus stop	A service worker that has to work offline.
166. Kitchen timer	One alarm, however many tabs are open.
172. Help desk	A strict Content Security Policy that nothing may break.
194. Meeting rooms	Three requests in a row, where each can fail on its own.

Cases

#	Case	What it is
1	Two-user realtime chat	Open a sandbox, join with a name, and send messages.
2	Concurrent edit	Two people open the same card on the board and both edit it.
3	Optimistic moves	Cards move between columns at once, before the server answers.
4	Export job	Export board as CSV starts a background job with progress.
5	Feature flag	New cards are created with one of two variants: an inline form or a dialog.
6	Due dates, time zones, and DST	Cards can have a due date.
7	A shared environment	Card titles are unique within a sandbox, and the board shows how many cards it has.
8	Magic-link sign-in	The Account page signs you in with a link sent by email.
9	A virtualized list	The Activity page lists 10,000 entries, rendering only the rows in view and loading them in pages.
10	A toast and a page that is never idle	Saving Settings shows "Settings saved" for 2 seconds.
11	Checkout total	The Shop page sells three products.
12	Shipping insurance	Checkout offers shipping insurance for 4.99 PLN, with no VAT on it.
13	Product reviews	Each product has a reviews page, linked from the Shop.
14	Editing a review	The browser that posted a review can edit it.
15	Splitting an order	Under your orders, "Split order" opens a page that divides the order total between 2 and 8 people.
16	The People picker	The split page chooses the number of people with a list built from ARIA roles, not a native select.
17	Cookie consent	The Deals page asks for cookie consent before it shows deals picked for you.
18	Gift cards	The Gift cards page sells gift cards.
19	Notes	The Notes page lists notes you can star, archive, or delete.
20	Budget	The Budget page keeps a list of expenses and charts them.
21	Your plan	The Plan page shows your Pro plan, 49.00 PLN a month, with the next payment on 1 December 2026.
22	Playlist	The Playlist page lists five songs in an order you can change.
23	Top up	The Top up page adds money to a wallet.
24	Draft	The Draft page holds one letter that saves itself.
25	Calendar	The Calendar page connects a calendar from Example Calendar, a separate sign-in service.
26	Contacts	The Contacts page imports contacts from a CSV file.
27	Stores	The Stores page finds the three stores nearest to you.
28	Quote	The Quote page multiplies a unit price by a quantity.
29	Booking	The Booking page books a room in three steps: Dates, Guests, and Review.
30	Feed	The Feed page lists posts, newest first.
31	Checklist	The Checklist page keeps a list of items and keeps working when the connection drops.
32	Vault	The Vault page keeps notes behind two-step verification with an authenticator app.
33	Basket	The Basket page keeps a basket in the browser, without the server.
34	Support	The Support page sends a message to support.
35	Receipt	The Receipt page shows a shop receipt with an order number and the time it was printed (24-hour clock).
36	Sign up	The Sign up page creates an account (nothing is stored).
37	Bio	The Bio page has a small rich-text editor with Bold and Italic buttons (Ctrl+B and Ctrl+I work too) and Save.
38	Search	The Search page finds products as you type.
39	Invoices	The Invoices page lists two invoices with a Download PDF link each.
40	Price filter	The Price filter page shows products between a lowest and a highest price, chosen with a slider that has two handles.
41	Reminders	The Reminders page reminds you about something in 1, 5, 15 or 60 minutes.
42	Address	The Address page edits your street, city and postcode.
43	Feedback	The Feedback page sends a star rating and an optional comment.
44	Share	The Share page shows an invite link with Copy link and New link buttons.
45	Updates	The Updates page tells you when a new version of the app has been released while the page was open.
46	Inbox	The Inbox page lists eight messages with a checkbox each.
47	Orders	The Orders page shows orders ten at a time, sorted on the server.
48	Files	The Files page lists five files.
49	Tasks	The Tasks page is a small to-do list with keyboard shortcuts.
50	Itinerary	The Itinerary page shows a three-day trip with a Print itinerary button.
51	Verify phone	The Verify phone page texts a code (nothing is really sent).
52	Order summary	The Order summary page can be shown in English or Arabic.
53	Shipping address	The Shipping address page saves a country and a postcode, and a state for the United States.
54	Gallery	The Gallery page shows 24 photos in two columns.
55	Holiday request	The Holiday request page picks a first and a last day, on a calendar or in the From and To fields.
56	Stay signed in	The Stay signed in page signs in [email protected] with the password correct horse.
57	Podcast	The Podcast page plays a 30-second episode (a quiet tone) with its own controls.
58	Bakery	The Bakery page has a site header with four links.
59	Session	The Session page signs you out after 90 seconds without activity.
60	Team	The Team page shows a Roadmap document and its members.
61	Meetings	The Meetings page adds a meeting at a date and time, once or every week for 4 weeks.
62	Directory	The Directory page lists 10,000 customers.
63	Confirm email	The Confirm email page asks for a 6-digit code, one box per digit.
64	Messages	The Messages page counts new messages in English or Polish.
65	Passkeys	The Passkeys page creates passkeys for ann and signs in with them.
66	Delivery	The Delivery page asks you to sign for a parcel.
67	Import	The Import page imports 100 customers and shows the progress as it happens.
68	Packing list	The Packing list page edits a list of things to pack.
69	Help centre	The Help centre opens articles without reloading the page.
70	Order review	The Order review page lists 12 items under a header that stays at the top, with a pay bar that stays at the bottom.
71	Sales report	The Sales report page adds up 20,000,000 sales by region.
72	Upload	The Upload page sends a file of up to 20 MB to the server.
73	Support ticket	The Support ticket page takes a description and pasted screenshots.
74	Timesheet	The Timesheet page is a grid of hours per day and project.
75	Shop reviews	The Shop reviews page shows a reviews widget in a sandboxed frame.
76	Country	The Country page is a list of 30 countries you can pick from with the keyboard.
77	Appearance	The Appearance page lets you pick a theme and how much motion you see.
78	Statement	The Statement page lists a month of transactions and downloads them as a CSV file.
79	Plans	The Plans page compares three plans, each with an info button that shows a tooltip.
80	Price alerts	The Price alerts page sends a browser notification when a product gets cheaper.
81	Live score	The Live score page follows a match and stops asking the server while the tab is hidden.
82	Mobile inbox	The Mobile inbox page deletes a message when you swipe it to the left, with an undo.
83	Change password	The Change password page changes the account password and works with password managers.
84	Flash sale	The Flash sale page counts down to the end of a sale by the shop's clock.
85	Class list	The Class list page sorts and searches 15 pupils with Polish names.
86	Newsletter	The Newsletter page marks an article as read once it has been on screen for 2 seconds.
87	Post editor	The Post editor page writes and publishes a blog post in a panel that scrolls.
88	Announcements	The Announcements page shows three banners you can dismiss.
89	Voice note	The Voice note page records a voice note with the microphone and saves it.
90	Price list	The Price list page checks for new prices and downloads the list only when it changed.
91	Contributors	The Contributors page shows names on small cards, cutting the ones that do not fit.
92	Product details	The Product details page shows four tabs of details about a hand grinder.
93	Files tree	The Files tree page shows folders and files in a tree you can open and close.
94	Promotions	The Promotions page shows a carousel of four offers that changes every 5 seconds.
95	Local notes	The Local notes page keeps notes in the browser's database and updates it safely across tabs.
96	Letter	The Letter page is a text box with its own Undo and Redo that work a word at a time.
97	Recipe	The Recipe page shares a recipe with the device's share sheet, or copies its link.
98	Photos	The Photos page shows five photos in a viewer that can go full screen.
99	Delivery details	The Delivery details page is a form that reflows on narrow screens and with large text.
100	Hotels	The Hotels page filters a hotel list in a sheet that covers the whole window.
101	Lamps	The Lamps page shows product cards with Save and Compare buttons for mouse, keyboard and touch.
102	Mailing list	The Mailing list page embeds a sign-up form that a separate script wires up after the page loads.
103	Trip tags	The Trip tags page turns typed text into tags, also when the text comes from an input method.
104	Concert tickets	The Concert tickets page sells tickets and must be up to date when the user returns with Back.
105	Privacy settings	The Privacy settings page has a pop-up hint for each option and a confirmation after saving.
106	Train ticket	The Train ticket page sells a ticket with optional extras over three steps.
107	Pancakes	The Pancakes page scales a recipe by servings and works out how many servings your flour makes.
108	Photo album	The Photo album page uploads a whole folder of photos, keeping its subfolders.
109	Floor plan	The Floor plan page zooms a plan with a pinch, Ctrl and the mouse wheel, or buttons.
110	Reading list	The Reading list page keeps the user signed in with a session stored in IndexedDB.
111	Bus stop	The Bus stop page links to a departures board that keeps working offline.
112	Workspace	The Workspace page opens on Setup or on the Dashboard, depending on the workspace's settings.
113	Saved searches	The Saved searches page lists saved searches and shows an empty state when there are none.
114	Groceries	The Groceries page adds products to a basket and announces each change to screen readers.
115	Event feedback	The Event feedback page has a form whose star rating is a custom element.
116	Shop dashboard	The Shop dashboard page has an orders widget that switches layout with its own width.
117	Highlights	The Highlights page lets the reader save selected text from an article.
118	Sell your bike	The Sell your bike page explains, to every user, why Publish is not available yet.
119	Expense claims	The Expense claims page submits claims after you sign in, and lets you sign in again without losing a claim when the session ends.
120	Flats	The Flats page lists flats to rent as cards that open the flat, with Save and Compare on each card.
121	Parking permit	The Parking permit page takes payment through card fields in an embedded frame.
122	Shared drive	The Shared drive page lists files with a custom right-click menu: Open, Duplicate and Delete.
123	Village hall	The Village hall page lists questions whose answers open and close, and can still be found while closed.
124	Assistant	The Assistant page has three conversations; answers arrive word by word, also while you read another conversation.
125	Comments	The Comments page has a comment box that grows with its text, up to six lines.
126	Alert settings	The Alert settings page has three on/off switches and a choice of summary email.
127	Choir sign-up	The Choir sign-up page shows its form step by step on narrow screens and all at once on wide ones.
128	Shared photos	The Shared photos page opens a photo on a tap and starts selecting photos when one is pressed and held.
129	Mail reader	The Mail reader page shows a message list and a message side by side, divided by a bar you can drag.
130	Receipts	The Receipts page attaches receipt files dragged from the computer onto it, or chosen with a button.
131	Guestbook	The Guestbook is a plain HTML page with a form, served by the server and usable without JavaScript.
132	Concert poster	The Concert poster page sizes the poster's headline so it fits on one line at any width.
133	Field notes	The Field notes page keeps notes in the browser's storage as you type.
134	Club activity	The Club activity page lists what happened in the club, with times such as "3 minutes ago".
135	Notice board	The Notice board page lists office notices and counts the ones you have not read yet.
136	Prints	The Prints page connects your CloudPix photo account through a pop-up window.
137	Study group	The Study group page is a group chat that shows who is typing.
138	Billing details	The Billing details page saves who invoices are made out to: a private person or a company.
139	Flight search	The Flight search page finds flights, and copes when the search is slow.
140	Bank transfer	The Bank transfer page sends money to an account number that is formatted as you type.
141	Library card	The Library card page takes a date of birth typed by hand and works out your age.
142	Village fête	The Village fête page links to a reply form that the server builds and a script improves.
143	Rooms	The Rooms page shows a guest house's three rooms with photos sized for each screen.
144	Radio favourites	The Radio favourites page lets you like songs, and keeps the saved likes in step with the screen.
145	Shift handover	The Shift handover page sends a note for the next shift, where @ mentions people.
146	Ticket contact	The Ticket contact page asks where to send tickets, and works with the browser's autofill.
147	Handbook	The Handbook page has a menu of sections that open and close, usable with a keyboard and a screen reader.
148	Barber	The Barber page books a haircut and holds the chosen time for 5 minutes.
149	Running order	The Running order page lists 30 acts of a village show, in an order you change by dragging.
150	Site photos	The Site photos page lists folders and photos in a table you sort by name, size or date.
151	Staff	The Staff page opens an edit dialog that loads a person's details while you move around it.
152	Support answers	The Support answers page filters help articles as you type and highlights the matches.
153	Tile order	The Tile order page builds an order that belongs to one browser tab and survives a reload.
154	Shoe size	The Shoe size page picks a size from a custom list that opens over its button.
155	Saved cards	The Saved cards page asks before removing a card, in a question that fades out.
156	Stock take	The Stock take page is a grid of counts you can fill by pasting cells from a spreadsheet.
157	Cookbook	The Cookbook page opens dialogs over a long list that must stay put behind them.
158	Trail map	The Trail map page opens from a service worker's saved copy and must update to a new version cleanly.
159	Phrasebook	The Phrasebook page adds phrases with Enter, including ones typed with an input method (IME).
160	Replies	The Replies page keeps an unsent reply per conversation in the browser, up to the last letter typed.
161	Payslips	On the Payslips site, the browser's Back and Forward buttons must never show payslips to someone who signed out.
162	Newsroom	The Newsroom page pages through stories with Load more, without repeats or gaps, and keeps your place when you come back from a story.
163	Members	The Members area sends you to the page you asked for after signing in, but never off the site.
164	Prime counter	The Prime counter page runs a count of several seconds that must not freeze the page, and can be cancelled or replaced.
165	Pay by bank	The Pay by bank page sends you to a bank on another site, which sends you back with the result.
166	Kitchen timer	The Kitchen timer is shared by all open tabs of the page and must ring exactly once when it ends.
167	Transcript	The Transcript page has a link for every line, and each link must land on its line, under the page's sticky header.
168	Team chat	The Team chat keeps you at the newest message as messages and photos arrive, unless you scrolled up to read.
169	Cinema	The Cinema page reserves seats, and its buttons must work from the moment they appear, on any connection.
170	Parts search	A search box that waits as long as the server asks after 429 Too Many Requests.
171	Staff guide	A contents bar that marks the section you are reading and jumps to a section on click.
172	Help desk	A page under a strict Content-Security-Policy with a chat whose code loads on the first click.
173	Video upload	An upload in 1 MB parts that carries on where the server stopped, after a lost connection or a reload.
174	Chat history	A conversation that loads older messages above when you scroll up, without moving what you read.
175	Close account	A page that closes the account, shown in this app's own preview frame but never in another site's.
176	Shipments	Parcels with long tracking numbers that must stay exact from the server to the screen and back.
177	Metronome	A metronome with page-wide keys that keeps working the same however often you leave and come back.
178	Loyalty points	Points read and spent through a partner API on another origin, straight from the browser.
179	Café dashboard	Three tiles that fail one at a time: a broken tile says so, reports it, and leaves the others working.
180	Printer status	A status that checks less and less often while the printer cannot be reached, and normally again once it can.
181	Holiday homes	Cards that load a home's details as soon as the pointer or keyboard reaches them, counting a view only when it is opened.
182	Profile photo	A photo turned and cut to a 256 × 256 square in the browser, then sent as a PNG.
183	Travel article	An article whose photos and newsletter box arrive after the text, without moving it.
184	Paper boat	A 12-second video with captions in English or Polish and a transcript that follows it.
185	Quick invoice	An invoice form with many buttons, where Enter saves and no other button ever does.
186	Library catalogue	A search kept in the page's address, so it survives a reload, a shared link and Back, whatever the text.
187	Team overview	Three panels loaded at once with a short-lived token that is renewed once, quietly, when it runs out.
188	Region packs	Map downloads with a progress bar that follows the bytes as they arrive, and a Cancel button.
189	Gym membership	Renewal dates for a membership that starts late in the month, in any time zone.
190	Courier pickup	A two-column booking form where the keyboard has to move in the order a person reads.
191	Recipe box	A list and an editor side by side, with answers kept in a cache that has to forget the right things.
192	Travel wallet	Balances in złoty, yen and Bahraini dinar, which have 2, 0 and 3 decimal places.
193	Weather	A weather widget that asks the server once per change and once every ten minutes, and no more.
194	Meeting rooms	Booking a room in three steps (book, send the invite, refresh the list) where a later step can fail on its own.
195	Shopping list	A list where a new item can be ticked or removed before the server has given it an id.
196	Class timetable	A month grid whose first weekday and weekend follow the visitor's language and region.
197	Guest invites	A box for many email addresses at once, where real but unusual addresses must get through.
198	Shared files	A list of shared file names, some of which use direction marks to hide what they are.
199	Exhibition	Paintings that open in a dialog with its own address, where Back closes the dialog instead of leaving.
200	Appointment reminders	An SMS reminder box that counts characters and messages the way phone networks do.
201	Parcel lockers	Choosing a parcel locker from a list sorted by distance, where full lockers cannot be chosen.
202	Ferry tickets	Ferry fares for adults and children with a family discount and a passenger limit.

Run it

docker compose up --build

Open http://localhost:3000 to browse the cases by topic, then start a sandbox. A sandbox is a private copy of the app; open its URL in a second window to be the second user.

Test hooks and API

Test hooks reset, seed and break a sandbox from a test. API lists the endpoints the pages use.

Stack

Node 24 or newer runs TypeScript directly; CI uses the newest Node release. Fastify serves the API, the WebSocket, and the React build from one process; data lives in an in-memory SQLite database, so a restart is a full reset. The client is React 19 with Vite and TanStack Query.

Develop

npm ci
npm run dev:server   # API on :3000 with test hooks
npm run dev:web      # Vite on :5173, proxies /api and /__test__
npm run typecheck
npm run test:unit
npm run build && npm run test:smoke   # opens every page in Chromium; axe scan of the shell

License

MIT. Made by bartech-lab.