Don't kick to login screen on network error (#4911)

* Don't kick the user on network errors

* Track online status for RQ

* Use health endpoint

* Update test with new behavior

* Only poll while offline

* Handle races between the check and network events

* Reduce the poll kickoff interval

* Don't cache partially fetched pinned feeds

This isn't a new issue but it's more prominent with the offline handling. We're currently silently caching pinned infos that failed to fetch. This avoids showing a big spinner on failure but it also kills all feeds which is very confusing. If the request to get feed gens fails, let's fail the whole query.

Then it can be retried.

src/state/session/__tests__/session-test.ts

@@ -1184,7 +1184,7 @@ describe('session', () => {
     expect(state.currentAgentState.did).toBe('bob-did')
   })
 
-  it('does soft logout on network error', () => {
+  it('ignores network errors', () => {
     let state = getInitialState([])
 
     const agent1 = new BskyAgent({service: 'https://alice.com'})
@@ -1217,11 +1217,9 @@ describe('session', () => {
       },
     ])
     expect(state.accounts.length).toBe(1)
-    // Network error should reset current user but not reset the tokens.
-    // TODO: We might want to remove or change this behavior?
     expect(state.accounts[0].accessJwt).toBe('alice-access-jwt-1')
     expect(state.accounts[0].refreshJwt).toBe('alice-refresh-jwt-1')
-    expect(state.currentAgentState.did).toBe(undefined)
+    expect(state.currentAgentState.did).toBe('alice-did')
     expect(printState(state)).toMatchInlineSnapshot(`
       {
         "accounts": [
@@ -1242,9 +1240,9 @@ describe('session', () => {
         ],
         "currentAgentState": {
           "agent": {
-            "service": "https://public.api.bsky.app/",
+            "service": "https://alice.com/",
           },
-          "did": undefined,
+          "did": "alice-did",
         },
         "needsPersist": true,
       }

src/state/session/agent.ts

@@ -12,6 +12,7 @@ import {tryFetchGates} from '#/lib/statsig/statsig'
 import {getAge} from '#/lib/strings/time'
 import {logger} from '#/logger'
 import {snoozeEmailConfirmationPrompt} from '#/state/shell/reminders'
+import {emitNetworkConfirmed, emitNetworkLost} from '../events'
 import {addSessionErrorLog} from './logging'
 import {
   configureModerationForAccount,
@@ -227,6 +228,7 @@ export function sessionAccountToSession(
 }
 
 // Not exported. Use factories above to create it.
+let realFetch = globalThis.fetch
 class BskyAppAgent extends BskyAgent {
   persistSessionHandler: ((event: AtpSessionEvent) => void) | undefined =
     undefined
@@ -234,6 +236,23 @@ class BskyAppAgent extends BskyAgent {
   constructor({service}: {service: string}) {
     super({
       service,
+      async fetch(...args) {
+        let success = false
+        try {
+          const result = await realFetch(...args)
+          success = true
+          return result
+        } catch (e) {
+          success = false
+          throw e
+        } finally {
+          if (success) {
+            emitNetworkConfirmed()
+          } else {
+            emitNetworkLost()
+          }
+        }
+      },
       persistSession: (event: AtpSessionEvent) => {
         if (this.persistSessionHandler) {
           this.persistSessionHandler(event)
@@ -257,7 +276,15 @@ class BskyAppAgent extends BskyAgent {
 
     // Now the agent is ready.
     const account = agentToSessionAccountOrThrow(this)
+    let lastSession = this.sessionManager.session
     this.persistSessionHandler = event => {
+      if (this.sessionManager.session) {
+        lastSession = this.sessionManager.session
+      } else if (event === 'network-error') {
+        // Put it back, we'll try again later.
+        this.sessionManager.session = lastSession
+      }
+
       onSessionChange(this, account.did, event)
       if (event !== 'create' && event !== 'update') {
         addSessionErrorLog(account.did, event)

src/state/session/reducer.ts

@@ -79,12 +79,8 @@ let reducer = (state: State, action: Action): State => {
         return state
       }
       if (sessionEvent === 'network-error') {
-        // Don't change stored accounts but kick to the choose account screen.
-        return {
-          accounts: state.accounts,
-          currentAgentState: createPublicAgentState(),
-          needsPersist: true,
-        }
+        // Assume it's transient.
+        return state
       }
       const existingAccount = state.accounts.find(a => a.did === accountDid)
       if (