frontend/wailsjs/ is deleted and frontend/bindings/ takes its place —
a real TypeScript module tree nested by Go import path, generated by
wails3's static analyser rather than by building the app and running
it. The @go alias absorbs the constant prefix, so a call site imports
'@go/library/library.js' and the codemod over all 93 sites was a
specifier rewrite plus splitting @go/models' namespaces into one
import per package.
The 12 SetContext bindings and the fake `context` model are gone, as
Phase 2's ServiceStartup port promised: 272 methods across 12
services, none of them plumbing.
@runtime/runtime is now a local shim (src/wails/runtime.ts) over
@wailsio/runtime, so the 22 EventsOn imports are untouched. It
unwraps v3's WailsEvent into v2's callback shape, which is exact here:
nothing in backend/events passes more than one data argument, and v3
only packs arguments into a slice when there is more than one.
v3 tells the truth about two things v2 lied about, and that is most of
the diff. A Go nil slice really does arrive as JSON null, and a Go
named string type really is an enum; v2 typed them as T[] and string.
utils/binding.ts states the app's actual contract — an absent list is
an empty list — once, at the boundary where it is true, and also drops
the CancellablePromise the app never cancels. Four test fixtures
widen an enum field back to its value union.
Not done, and Phase 5's to fix: frontend/test/support/wails-fake.ts
still fakes window.go, which v3 does not have, so `make ui-test` is
broken and harness.test.ts fails to compile on EventsEmit. That test
also asserts v2 ordering that no longer holds — v3's Events.Emit calls
the backend and does not notify in-page listeners at all.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UDCbcCZQepnpSQYJ6SxxZm
An event carries what a consumer needs so it never has to invalidate.
- `library-store` answers `TrackPlayCountChanged` by patching one
track, replacing the tracks array (consumers key memoized caches on
its identity) while sharing every unchanged Track — instead of
discarding four collections and refetching 25 MB per song.
- `playlist-store` answers `PlaylistTracksChanged` by refetching the
one playlist the event names, plus the summaries, since `UpdatedAt`
is a sort key. 2 668 kB and 172 ms for one heart, against 2.0 kB. It
falls back to a full invalidate only where a patch cannot be shown
to be equivalent: no id, a cold cache, an unknown id, or a fetch
already in flight. And a store with no subscriber fetches nothing —
the singleton's constructor used to put every track of every
playlist on the path to first paint for a view the user might never
open.
- `library-store` guards every fetch with a cache generation and holds
the request itself instead of deriving a promise from subscriber
notifications, which fixes the library-filter race and the
never-settling waiter together: they are the same bug seen from
either end.
- `explore-cache`'s two art caches are bounded, sharing one exported
cap constant — the artist photo's data URL is held by both, so
capping either alone frees nothing at all and reads as a fix that
did not work.
- `search-store` deliberately does *not* coalesce its notify: deferring
makes a subscriber that unsubscribes synchronously after a `setTerm`
miss the notification entirely, which is a semantic change rather
than an optimisation, and this is the store on the keystroke path.
- `selection-controller` retains its keys across a refetch rather than
clearing them, since they are file paths and those survive one, and
`getSelectedKeysOrdered()` gains an early exit. It stays a walk of
the list: an index goes stale on any re-sort, re-filter or refetch
while a file path survives all three, and 3 ms does not buy a
silently mis-ordered queue insert.
yonluandClaude Opus 5
logan