chore(refactor): include version in steps for WebsocketPolyfill

Signed-off-by: Max <[email protected]>

src/helpers/steps.ts

@@ -0,0 +1,31 @@
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+import type { FlatStep, Session, Step } from '../services/SyncService'
+import { COLLABORATOR_DISCONNECT_TIME } from '../services/SyncService'
+
+/**
+ * Get the recent awareness messages as steps
+ * @param sessions to process.
+ */
+export function awarenessSteps(sessions: Session[]): FlatStep[] {
+	const lastContactThreshold = Math.floor(Date.now() / 1000) - COLLABORATOR_DISCONNECT_TIME
+	return sessions
+		.filter((s) => s.lastContact > lastContactThreshold)
+		.filter((s) => Boolean(s.lastAwarenessMessage))
+		.map((s) => ({ step: s.lastAwarenessMessage }))
+}
+
+/**
+ * Flatten the provided steps and assign the version to each of them.
+ * @param steps to process.
+ */
+export function flatSteps(steps: Step[]): FlatStep[] {
+	return steps.flatMap(
+		(s) => s.data.map(
+			(step) => ({ step, version: s.version }),
+		),
+	)
+}

src/services/SyncService.ts

@@ -9,11 +9,11 @@ import mitt from 'mitt'
 import debounce from 'debounce'
 
 import PollingBackend from './PollingBackend.js'
-import Outbox from './Outbox.js'
+import Outbox from './Outbox'
 import SessionApi, { Connection } from './SessionApi.js'
 import { documentStateToStep } from '../helpers/yjs.js'
 import { logger } from '../helpers/logger.js'
-
+import { awarenessSteps, flatSteps } from '../helpers/steps'
 /**
  * Timeout after which the editor will consider a document without changes being synced as idle
  * The session will be terminated and the document will stay open in read-only mode with a button to reconnect if needed
@@ -64,6 +64,14 @@ export interface Step {
 	sessionId: number
 }
 
+/*
+ * Step as what we process it in the WebsocketPolyfill
+ */
+export interface FlatStep {
+	step: string
+	version?: number
+}
+
 export interface UserSession {
 	id: number
 	userId: string
@@ -301,40 +309,20 @@ class SyncService {
 		steps,
 		document,
 		sessions = [],
-	} : {
-		steps: Step[],
-		document?: Document,
-		sessions?: Session[],
+	}: {
+		steps: Step[]
+		document?: object
+		sessions?: Session[]
 	}) {
-		const awareness = sessions
-			.filter(s => s.lastContact > (Math.floor(Date.now() / 1000) - COLLABORATOR_DISCONNECT_TIME))
-			.filter(s => s.lastAwarenessMessage)
-			.map(s => {
-				return { step: s.lastAwarenessMessage }
-			})
-		const newSteps = [...awareness]
-		for (let i = 0; i < steps.length; i++) {
-			const singleSteps = steps[i].data
-			if (this.version < steps[i].version) {
-				this.version = steps[i].version
-			}
-			if (!Array.isArray(singleSteps)) {
-				logger.error('Invalid step data, skipping step', { step: steps[i] })
-				// TODO: recover
-				continue
-			}
-			singleSteps.forEach(step => {
-				newSteps.push({
-					step,
-				})
-			})
-		}
-		this.lastStepPush = Date.now()
 		this.bus.emit('sync', {
-			steps: newSteps,
+			steps: [
+				...awarenessSteps(sessions),
+				...flatSteps(steps),
+			],
 			document,
-			version: this.version,
+			version: Math.max(this.version, ...steps.map((s) => s.version)),
 		})
+		this.lastStepPush = Date.now()
 	}
 
 	checkIdle() {