enh(sync): updateFromContent()

This could be the basis for automatically merging
changes from an offline editing session
and changes by overwriting the doc.

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

Author: max-nextcloud

src/helpers/updateFromContent.ts

@@ -0,0 +1,42 @@
+/**
+ * SPDX-FileCopyrightText: 2023 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+import { Collaboration } from '@tiptap/extension-collaboration'
+import escapeHtml from 'escape-html'
+import { applyUpdate, Doc, encodeStateAsUpdate, encodeStateVector } from 'yjs'
+import { createPlainEditor, createRichEditor } from '../EditorFactory.js'
+import markdownit from '../markdownit/index.js'
+
+export const updateFromContent = (
+	baseDoc: Doc,
+	content: string,
+	{ isRichEditor }: { isRichEditor: boolean },
+): Uint8Array => {
+	// work on a copy
+	const copy = new Doc()
+	// we might still want to only apply this once
+	// copy.clientID = 0
+	applyUpdate(copy, encodeStateAsUpdate(baseDoc))
+	setContent(copy, content, { isRichEditor })
+	return encodeStateAsUpdate(copy, encodeStateVector(baseDoc))
+}
+
+const setContent = (
+	doc: Doc,
+	content: string,
+	{ isRichEditor }: { isRichEditor: boolean },
+) => {
+	const html = isRichEditor
+		? markdownit.render(content) + '<p/>'
+		: `<pre>${escapeHtml(content)}</pre>`
+	const editor = isRichEditor
+		? createRichEditor({
+				extensions: [Collaboration.configure({ document: doc })],
+			})
+		: createPlainEditor({
+				extensions: [Collaboration.configure({ document: doc })],
+			})
+	editor.commands.setContent(html)
+}

src/tests/helpers/updateFromContent.spec.ts

@@ -0,0 +1,103 @@
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+import { Collaboration } from '@tiptap/extension-collaboration'
+import { describe, expect, it } from 'vitest'
+import * as Y from 'yjs'
+import type { Connection } from '../../composables/useConnection.js'
+import { createRichEditor } from '../../EditorFactory.js'
+import { createMarkdownSerializer } from '../../extensions/Markdown.js'
+import { updateFromContent } from '../../helpers/updateFromContent'
+
+
+describe('apply content', () => {
+
+	it('applies content to an empty doc', () => {
+		const ydoc = new Y.Doc()
+		const content = '## Hello world'
+		const update = updateFromContent(ydoc, content, { isRichEditor: true })
+		expect(contentWithUpdates(Y.encodeStateAsUpdate(ydoc), update)).toBe(content)
+	})
+
+	it('applies content to a doc that already has content', () => {
+		const ydoc = new Y.Doc()
+		const initialContent = `
+## Hello world
+
+### Section one
+
+Nothing to see here.
+
+### Section two
+
+Carry on!
+`
+		const changeOne = `
+## Hello world
+
+### Section one
+
+Uh... wow!
+
+### Section two
+
+Carry on!
+`
+		const changeTwo = `
+## Hello world
+
+### Section one
+
+Nothing to see here.
+
+### Section two
+
+What's that?
+`
+
+		const initialUpdate = updateFromContent(ydoc, initialContent, { isRichEditor: true })
+		Y.applyUpdate(ydoc, initialUpdate)
+		const updateOne = updateFromContent(ydoc, changeOne, { isRichEditor: true })
+		const updateTwo = updateFromContent(ydoc, changeTwo, { isRichEditor: true })
+		expect(contentWithUpdates(initialUpdate, updateOne, updateTwo))
+			.toMatchInlineSnapshot(`
+				"## Hello world
+
+				### Section one
+
+				Uh... wow!
+
+				### Section two
+
+				What's that?"
+			`)
+	})
+
+})
+
+/**
+ * Apply all updates to a new ydoc and return the markdown content
+ * @param updates updates to apply
+ */
+function contentWithUpdates(...updates: Uint8Array[]) {
+	const dummyConnection: Connection = {
+		documentId: 123,
+		sessionId: 234,
+		sessionToken: 'token',
+		baseVersionEtag: 'etag',
+		filePath: '/file.md',
+	}
+	const ydoc = new Y.Doc()
+	updates.forEach((update) => {
+		Y.applyUpdate(ydoc, update)
+	})
+	const editor = createRichEditor({
+		connection: dummyConnection,
+		extensions: [Collaboration.configure({ document: ydoc })],
+		relativePath: '',
+	})
+	const serializer = createMarkdownSerializer(editor.schema)
+	return serializer.serialize(editor.state.doc)
+}