# Notebook — the library's example application

A minimal application written against `@ng-eventually/polyfill`, in plain DOM.

It exists for two reasons, and the second is the one that matters.

**It shows how to use the library.** Every call in `app.ts` is what a real consumer writes. There is no test scaffolding, no privileged import, no reaching into the library's internals — it resolves `@ng-eventually/polyfill` as an external consumer does. If something reads awkwardly here, it reads awkwardly for everyone.

**It is what the applicative e2e suite drives** (`packages/polyfill/e2e/notebook.ts`, `bun run test:e2e:app`). The other suite talks to a bag of methods on `window.__sdk`, which proves the functions run but never that an application can be written with them — and that gap shipped a real defect once: a document's inbox was green in tests and unusable in practice, because the harness handed an address across an identity boundary through a variable, something no application can do. Here each identity is its own browser page, and the only values that cross between them are the ones that cross in life: a note's reference, copied off one screen, and an identifier typed into a field.

It has already paid for itself: writing it surfaced that `UnionSubject` returned `string` where the values are always document references (so a consumer had to cast whatever it had just read before passing it back), and that the access gate normalized what a user typed but not what the URL carried.

## What it exercises

Signing in, writing notes by scope, listing one's own, reading a note from its bare reference, handing a reader the key to a protected note, opening a note for messages, leaving a message on someone else's note, and reacting to changes.

The four journeys the suite runs, and what each proves:

| Journey | What it proves |
|---|---|
| Bob reads Alice's PUBLIC note from its reference alone | A public store serves its notes' keys — a bare reference is enough, and no key ever crosses |
| Alice's PROTECTED note stays shut until she shares it | The same gesture, the opposite outcome, decided by where the note sits and not by what was sent |
| Bob leaves a message on Alice's note, and only Alice reads it | A depositor FINDS the address from the note itself; depositing grants no reading |
| Each actor's list holds their own notes | The boundary, seen from the only place that matters: the screen |

It has also found three defects of its own, each one the harness could not see. The first turned out to be a LIBRARY defect rather than an application one: the connection work had to be awaited at sign-in, or a note just shared with you read as unreadable — so `ensureIdentity` now awaits it, and `connectedUser` left the published surface. The other two were the application's: a stale answer stayed on screen beside a fresh question, and changing the scope did not refresh the list.

## Running it

`cd packages/polyfill && bun run test:e2e:app` builds it, serves it, and drives it against the real broker. To open it by hand you need a wallet: serve the folder with a bundled `app.js` and a `/shared-wallet.ngw`, and set `__NOTEBOOK_WALLET_PASSWORD__`.