fix(app): keep hydrated state across gateway session resumes (#1862)

fluxer_app/src/features/read_state/state/ReadStates.ts

@@ -11,10 +11,6 @@ import {resolveReadStateAckDecision} from '@app/features/read_state/state/read_s
 import {ReadStateEntry} from '@app/features/read_state/state/read_states/ReadStateEntry';
 import {resolveReadStateIncomingMessageDecision} from '@app/features/read_state/state/read_states/ReadStateIncomingMessageMachine';
 import {resolveReadStateServerAckDecision} from '@app/features/read_state/state/read_states/ReadStateServerAckMachine';
-import {
-	resolveUnreadJumpAnchor,
-	type UnreadJumpAnchor,
-} from '@app/features/read_state/state/read_states/ReadStateUnreadAnchor';
 import {
 	ACK_BATCH_DELAY_MS,
 	ACK_BATCH_SIZE,
@@ -50,8 +46,6 @@ import {observable, runInAction} from 'mobx';
 
 export type {GatewayReadState};
 
-export type {UnreadJumpAnchor};
-
 const logger = new Logger('ReadStates');
 
 class ReadStates {
@@ -351,20 +345,6 @@ class ReadStates {
 		return state?.supportsUnreadTracking() ? state.visualUnreadMessageId : null;
 	}
 
-	getUnreadJumpAnchor(channelId: string): UnreadJumpAnchor | null {
-		const state = this.getIfExists(channelId);
-		if (state == null) {
-			return null;
-		}
-		return resolveUnreadJumpAnchor({
-			canBeUnread: state.canBeUnread(),
-			canTrackUnreads: state.supportsUnreadTracking(),
-			hasUnread: state.hasUnread(),
-			oldestUnreadMessageId: state.oldestUnreadMessageId,
-			ackMessageId: state.ackMessageId,
-		});
-	}
-
 	getChannelIds(): Array<ChannelId> {
 		return Array.from(this.states.keys());
 	}
@@ -409,7 +389,7 @@ class ReadStates {
 		this.notifyChange(channelId);
 	}
 
-	handleConnectionOpen(action: {
+	handleGatewayReady(action: {
 		readState: Array<GatewayReadState>;
 		readStateProto?: string;
 		channels: Array<ChannelPayload>;

fluxer_app/src/features/read_state/state/read_states/ReadStateUnreadAnchor.test.ts

@@ -1,46 +0,0 @@
-// SPDX-License-Identifier: AGPL-3.0-or-later
-
-import {describe, expect, it} from 'vitest';
-import {resolveUnreadJumpAnchor, type UnreadJumpAnchorInput} from './ReadStateUnreadAnchor';
-
-function input(overrides: Partial<UnreadJumpAnchorInput> = {}): UnreadJumpAnchorInput {
-	return {
-		canBeUnread: true,
-		canTrackUnreads: true,
-		hasUnread: true,
-		oldestUnreadMessageId: '900',
-		ackMessageId: '100',
-		...overrides,
-	};
-}
-
-describe('resolveUnreadJumpAnchor', () => {
-	it('anchors on the oldest unread message when it is known', () => {
-		expect(resolveUnreadJumpAnchor(input())).toEqual({messageId: '900', offset: 0});
-	});
-
-	it('anchors just after the ack when the oldest unread message is unknown', () => {
-		expect(resolveUnreadJumpAnchor(input({oldestUnreadMessageId: null}))).toEqual({messageId: '100', offset: 1});
-	});
-
-	it('returns no anchor when the channel has nothing unread', () => {
-		expect(resolveUnreadJumpAnchor(input({hasUnread: false}))).toBeNull();
-	});
-
-	it('returns no anchor when the channel cannot be unread', () => {
-		expect(resolveUnreadJumpAnchor(input({canBeUnread: false}))).toBeNull();
-	});
-
-	it('returns no anchor when unreads are not trackable for the channel', () => {
-		expect(resolveUnreadJumpAnchor(input({canTrackUnreads: false}))).toBeNull();
-	});
-
-	it('returns no anchor when neither an unread boundary nor an ack exists', () => {
-		expect(resolveUnreadJumpAnchor(input({oldestUnreadMessageId: null, ackMessageId: null}))).toBeNull();
-	});
-
-	it('anchors on the unread boundary regardless of how far behind the ack is', () => {
-		const anchor = resolveUnreadJumpAnchor(input({ackMessageId: '1', oldestUnreadMessageId: '2'}));
-		expect(anchor).toEqual({messageId: '2', offset: 0});
-	});
-});

fluxer_app/src/features/read_state/state/read_states/ReadStateUnreadAnchor.ts

@@ -1,27 +0,0 @@
-// SPDX-License-Identifier: AGPL-3.0-or-later
-
-export interface UnreadJumpAnchorInput {
-	canBeUnread: boolean;
-	canTrackUnreads: boolean;
-	hasUnread: boolean;
-	oldestUnreadMessageId: string | null;
-	ackMessageId: string | null;
-}
-
-export interface UnreadJumpAnchor {
-	messageId: string;
-	offset: number;
-}
-
-export function resolveUnreadJumpAnchor(input: UnreadJumpAnchorInput): UnreadJumpAnchor | null {
-	if (!input.canBeUnread || !input.canTrackUnreads || !input.hasUnread) {
-		return null;
-	}
-	if (input.oldestUnreadMessageId != null) {
-		return {messageId: input.oldestUnreadMessageId, offset: 0};
-	}
-	if (input.ackMessageId == null) {
-		return null;
-	}
-	return {messageId: input.ackMessageId, offset: 1};
-}