phase 4: delete the session bridge (SessionAgent, agent.ts, agentToLexClient)

src/state/session/clients.ts

@@ -1,59 +1,10 @@
-import {type AtpAgent} from '@atproto/api'
 import {Client} from '@atproto/lex-client'
 import {type PasswordSession} from '@atproto/lex-password-session'
 import {api} from '@bsky.app/sdk'
 
-import {PUBLIC_BSKY_SERVICE} from '#/lib/constants'
+import {BLUESKY_PROXY_HEADER, PUBLIC_BSKY_SERVICE} from '#/lib/constants'
 import {networkAwareFetch} from './session-core'
 
-/**
- * Stable per-agent cache of lex `Client` instances. We never reuse an
- * `AtpAgent` (the session provider disposes the previous one on switch), so a
- * `WeakMap` keyed on the agent gives us a client whose identity is stable for
- * the lifetime of that agent. This keeps React Query keys and hook consumers
- * from churning on every render.
- */
-const clientForAgent = new WeakMap<AtpAgent, Client>()
-
-/**
- * Wrap a live {@link AtpAgent} as a lex {@link Client}, bridging the old session
- * source of truth to the new SDK so features can migrate incrementally.
- *
- * The client talks to the agent through the minimal lex `Agent` interface
- * (`{ did, fetchHandler }`). We deliberately route `fetchHandler` through
- * `agent.fetchHandler` (the agent's XRPC dispatch layer) rather than
- * `agent.sessionManager.fetchHandler`:
- *
- * - `agent.fetchHandler` (see @atproto/api `agent.js`) is where the agent
- *   applies its configured `atproto-proxy` header (set via `configureProxy` to
- *   the appview) and its `atproto-accept-labelers` header, before delegating to
- *   `sessionManager.fetchHandler` for authorization + token refresh.
- * - `sessionManager.fetchHandler` (`CredentialSession`) only adds the auth
- *   token and handles refresh - it does NOT proxy or attach labelers. Wrapping
- *   it directly would silently drop appview proxying and moderation labelers.
- *
- * Because the wrapped agent already applies proxy + labeler headers, we do NOT
- * pass a `service` option to the `Client` (lex-client only sets `atproto-proxy`
- * when `service` is provided) and we leave `Client.appLabelers` at its default
- * empty set. This avoids double-setting either header.
- *
- * Results are memoized per-agent so the returned client is referentially stable.
- */
-export function agentToLexClient(agent: AtpAgent): Client {
-  const cached = clientForAgent.get(agent)
-  if (cached) {
-    return cached
-  }
-  const client = new Client({
-    get did() {
-      return agent.did
-    },
-    fetchHandler: (path, init) => agent.fetchHandler(path, init),
-  })
-  clientForAgent.set(agent, client)
-  return client
-}
-
 /**
  * Lazily-constructed unauthenticated client pointed at the public appview. It
  * hits {@link PUBLIC_BSKY_SERVICE} directly, mirroring `createPublicAgent`'s
@@ -135,18 +86,26 @@ export function getUnauthenticatedClient(): Client {
 /**
  * Build the authed appview client over a {@link PasswordSession}.
  *
- * Requests are proxied to the Bluesky appview (`atproto-proxy:
- * did:web:api.bsky.app#bsky_appview`) and carry the per-instance labelers.
- * The Bluesky moderation labeler (`api.moderation.did`) is always included as
- * a base labeler because sending ANY `atproto-accept-labelers` header replaces
- * the server-side default - so we must re-assert it to keep it active.
+ * Requests are proxied to the Bluesky appview and carry the per-instance
+ * labelers. The Bluesky moderation labeler (`api.moderation.did`) is always
+ * included as a base labeler because sending ANY `atproto-accept-labelers`
+ * header replaces the server-side default - so we must re-assert it to keep it
+ * active.
+ *
+ * The proxy `service` is read from `BLUESKY_PROXY_HEADER.get()` (rather than
+ * hard-coding `api.app.service`). Its default value equals `api.app.service`
+ * (`did:web:api.bsky.app#bsky_appview`), so production is unchanged; the getter
+ * exists so the e2e `TestCtrls` hack can retarget the appview by calling
+ * `BLUESKY_PROXY_HEADER.set()` before sign-in (the client is built at
+ * sign-in, so it picks up the override).
  */
 export function buildAppviewClient(
   session: PasswordSession,
   labelerDids: string[],
 ): Client {
   return new Client(session, {
-    service: api.app.service,
+    /* BLUESKY_PROXY_HEADER.get() is a `did:...#...` ProxyHeaderValue, assignable to Service */
+    service: BLUESKY_PROXY_HEADER.get(),
     /* labelerDids are validated DID strings; cast to the DidString template type */
     labelers: [
       api.moderation.did,