Add cursor moving (#19)

frontend/obsidian-plugin/jest.config.js

@@ -0,0 +1,3 @@
+module.exports = {
+	preset: "ts-jest/presets/js-with-babel-esm"
+};

frontend/obsidian-plugin/package.json

@@ -6,7 +6,7 @@
 	"scripts": {
 		"dev": "webpack watch --mode development",
 		"build": "webpack --mode production",
-		"test": "jest --passWithNoTests",
+		"test": "jest",
 		"version": "node version-bump.mjs"
 	},
 	"keywords": [],
@@ -36,4 +36,4 @@
 		"webpack": "^5.98.0",
 		"webpack-cli": "^6.0.1"
 	}
-}
+}

frontend/obsidian-plugin/src/obsidian-file-system.ts

@@ -1,6 +1,12 @@
 import type { Stat, Vault, Workspace } from "obsidian";
 import { MarkdownView, normalizePath } from "obsidian";
-import type { FileSystemOperations, RelativePath } from "sync-client";
+import type {
+	FileSystemOperations,
+	RelativePath,
+	TextWithCursors
+} from "sync-client";
+import { lineAndColumnToPosition } from "./utils/line-and-column-to-position";
+import { positionToLineAndColumn } from "./utils/position-to-line-and-column";
 
 export class ObsidianFileSystemOperations implements FileSystemOperations {
 	public constructor(
@@ -42,20 +48,50 @@ export class ObsidianFileSystemOperations implements FileSystemOperations {
 
 	public async atomicUpdateText(
 		path: RelativePath,
-		updater: (currentContent: string) => string
+		updater: (current: TextWithCursors) => TextWithCursors
 	): Promise<string> {
 		path = normalizePath(path);
 
 		const view = this.workspace.getActiveViewOfType(MarkdownView);
+
 		if (view?.file?.path === path) {
-			const result = updater(view.editor.getValue());
-			const position = view.editor.getCursor();
-			view.editor.setValue(result);
-			view.editor.setCursor(position);
-			return result;
+			const cursor = view.editor.getCursor();
+			const text = view.editor.getValue();
+			const result = updater({
+				text,
+				cursors: [
+					{
+						id: 0,
+						characterPosition: lineAndColumnToPosition(
+							text,
+							cursor.line,
+							cursor.ch
+						)
+					}
+				]
+			});
+
+			view.editor.setValue(result.text);
+
+			result.cursors.forEach((movedCursor) => {
+				const { line, column } = positionToLineAndColumn(
+					result.text,
+					movedCursor.characterPosition
+				);
+				view.editor.setCursor(line, column);
+			});
+
+			return result.text;
 		}
 
-		return this.vault.adapter.process(path, updater);
+		return this.vault.adapter.process(
+			path,
+			(text) =>
+				updater({
+					text,
+					cursors: []
+				}).text
+		);
 	}
 
 	public async getFileSize(path: RelativePath): Promise<number> {

frontend/obsidian-plugin/src/utils/line-and-column-to-position.test.ts

@@ -0,0 +1,43 @@
+import { lineAndColumnToPosition } from "./line-and-column-to-position";
+
+describe("lineAndColumnToPosition", () => {
+	it("should return the correct position for the first line", () => {
+		const text = "Hello\nWorld";
+		const position = lineAndColumnToPosition(text, 0, 3);
+		expect(position).toBe(3);
+	});
+
+	it("should return the correct position for the second line", () => {
+		const text = "Hello\nWorld";
+		const position = lineAndColumnToPosition(text, 1, 2);
+		expect(position).toBe(8);
+	});
+
+	it("should return the correct position for an empty string", () => {
+		const text = "";
+		const position = lineAndColumnToPosition(text, 0, 0);
+		expect(position).toBe(0);
+	});
+
+	it("should handle a single-line string correctly", () => {
+		const text = "SingleLine";
+		const position = lineAndColumnToPosition(text, 0, 5);
+		expect(position).toBe(5);
+	});
+
+	it("should handle multi-line strings with varying lengths", () => {
+		const text = "Line1\nLongerLine2\nShort3";
+		const position = lineAndColumnToPosition(text, 2, 4);
+		expect(position).toBe(22);
+	});
+
+	it("should throw an error if the line number is out of range", () => {
+		const text = "Line1\nLine2";
+		expect(() => lineAndColumnToPosition(text, 3, 0)).toThrow();
+	});
+
+	it("should throw an error if the column number is out of range", () => {
+		const text = "Line1\nLine2";
+		expect(() => lineAndColumnToPosition(text, 1, 10)).toThrow();
+	});
+});

frontend/obsidian-plugin/src/utils/line-and-column-to-position.ts

@@ -0,0 +1,34 @@
+/**
+ * Converts line and column coordinates to an absolute character position in a text string.
+ *
+ * @param line - The zero-based line number
+ * @param column - The zero-based column number
+ * @param text - The text string to calculate position in
+ * @returns The absolute character position (zero-based index) in the text string
+ * @throws Error if line number is out of range
+ * @throws Error if column number is out of range
+ */
+export function lineAndColumnToPosition(
+	text: string,
+	line: number,
+	column: number
+): number {
+	const lines = text.split("\n");
+
+	if (line >= lines.length) {
+		throw new Error(`Line number ${line} is out of range.`);
+	}
+
+	if (column > lines[line].length) {
+		throw new Error(`Column number ${column} is out of range.`);
+	}
+
+	let position = 0;
+	for (let i = 0; i < line; i++) {
+		position += lines[i].length + 1;
+	}
+
+	position += column;
+
+	return position;
+}

frontend/obsidian-plugin/src/utils/position-to-line-and-column.test.ts

@@ -0,0 +1,69 @@
+import { positionToLineAndColumn } from "./position-to-line-and-column";
+
+describe("positionToLineAndColumn", () => {
+	test("converts position to line and column in a single line text", () => {
+		const text = "Hello, world!";
+		expect(positionToLineAndColumn(text, 0)).toEqual({
+			line: 0,
+			column: 1
+		});
+		expect(positionToLineAndColumn(text, 7)).toEqual({
+			line: 0,
+			column: 8
+		});
+		expect(positionToLineAndColumn(text, 12)).toEqual({
+			line: 0,
+			column: 13
+		});
+	});
+
+	test("converts position to line and column in multi-line text", () => {
+		const text = "First line\nSecond line\nThird line";
+		expect(positionToLineAndColumn(text, 0)).toEqual({
+			line: 0,
+			column: 1
+		});
+		expect(positionToLineAndColumn(text, 10)).toEqual({
+			line: 0,
+			column: 11
+		});
+		expect(positionToLineAndColumn(text, 15)).toEqual({
+			line: 1,
+			column: 5
+		});
+		expect(positionToLineAndColumn(text, 26)).toEqual({
+			line: 2,
+			column: 4
+		});
+	});
+
+	test("handles positions at line breaks", () => {
+		const text = "Line\nBreak";
+		expect(positionToLineAndColumn(text, 4)).toEqual({
+			line: 0,
+			column: 5
+		});
+		expect(positionToLineAndColumn(text, 5)).toEqual({
+			line: 1,
+			column: 1
+		});
+	});
+
+	test("handles empty input", () => {
+		expect(positionToLineAndColumn("", 0)).toEqual({ line: 0, column: 1 });
+	});
+
+	test("handles positions at the end of text", () => {
+		const text = "End";
+		expect(positionToLineAndColumn(text, 3)).toEqual({
+			line: 0,
+			column: 4
+		});
+	});
+
+	test("throws error for position out of range", () => {
+		const text = "Short text";
+		expect(() => positionToLineAndColumn(text, 15)).toThrow();
+		expect(() => positionToLineAndColumn(text, -1)).toThrow();
+	});
+});

frontend/obsidian-plugin/src/utils/position-to-line-and-column.ts

@@ -0,0 +1,30 @@
+/**
+ * Converts a character position in text to line and column numbers.
+ *
+ * @param text The text content to analyze
+ * @param position The character position to convert
+ * @returns An object containing line and column numbers (0-based index for line, 1-based index for column)
+ * @throws Will throw an error if the position is negative or exceeds the text length
+ */
+export function positionToLineAndColumn(
+	text: string,
+	position: number
+): { line: number; column: number } {
+	if (position < 0) {
+		throw new Error("Position cannot be negative");
+	}
+
+	if (position > text.length) {
+		throw new Error(
+			`Position ${position} exceeds text length ${text.length}`
+		);
+	}
+
+	const textUpToPosition = text.substring(0, position);
+	const lines = textUpToPosition.split("\n");
+
+	const line = lines.length - 1; // 0-based index
+	const column = lines[lines.length - 1].length + 1; // 1-based index
+
+	return { line, column };
+}

frontend/sync-client/src/file-operations/file-operations.test.ts

@@ -6,7 +6,10 @@ import type {
 import { FileOperations } from "./file-operations";
 import { Logger } from "../tracing/logger";
 import { assertSetContainsExactly } from "../utils/assert-set-contains-exactly";
-import type { FileSystemOperations } from "./filesystem-operations";
+import type {
+	FileSystemOperations,
+	TextWithCursors
+} from "./filesystem-operations";
 import init, { base64ToBytes } from "sync_lib";
 import fs from "fs";
 
@@ -43,7 +46,7 @@ class FakeFileSystemOperations implements FileSystemOperations {
 	}
 	public async atomicUpdateText(
 		_path: RelativePath,
-		_updater: (currentContent: string) => string
+		_updater: (current: TextWithCursors) => TextWithCursors
 	): Promise<string> {
 		throw new Error("Method not implemented.");
 	}

frontend/sync-client/src/file-operations/file-operations.ts

@@ -1,7 +1,16 @@
 import type { Logger } from "../tracing/logger";
-import type { FileSystemOperations } from "./filesystem-operations";
+import type {
+	FileSystemOperations,
+	TextWithCursors
+} from "./filesystem-operations";
 import type { Database, RelativePath } from "../persistence/database";
-import { isBinary, isFileTypeMergable, mergeText } from "sync_lib";
+import {
+	CursorPosition,
+	isBinary,
+	isFileTypeMergable,
+	mergeTextWithCursors,
+	TextWithCursors as RustTextWithCursors
+} from "sync_lib";
 import { SafeFileSystemOperations } from "./safe-filesystem-operations";
 
 export class FileOperations {
@@ -90,18 +99,45 @@ export class FileOperations {
 		const expectedText = new TextDecoder().decode(expectedContent); // this comes from a previous read which must only have \n line endings
 		const newText = new TextDecoder().decode(newContent); // this comes from the server which stores text with \n line endings
 
-		await this.fs.atomicUpdateText(path, (currentText) => {
-			currentText = currentText.replace(this.nativeLineEndings, "\n");
+		await this.fs.atomicUpdateText(
+			path,
+			({ text, cursors }: TextWithCursors): TextWithCursors => {
+				text = text.replace(this.nativeLineEndings, "\n");
 
-			this.logger.debug(
-				`Performing a 3-way merge for ${path} with the expected content`
-			);
+				this.logger.debug(
+					`Performing a 3-way merge for ${path} with the expected content`
+				);
 
-			return mergeText(expectedText, currentText, newText).replace(
-				"\n",
-				this.nativeLineEndings
-			);
-		});
+				const left = new RustTextWithCursors(
+					text,
+					cursors.map(
+						(cursor) =>
+							new CursorPosition(
+								cursor.id,
+								cursor.characterPosition
+							)
+					)
+				);
+				const right = new RustTextWithCursors(newText, []);
+				const merged = mergeTextWithCursors(expectedText, left, right);
+
+				const resultText = merged
+					.text()
+					.replace("\n", this.nativeLineEndings);
+
+				const resultCursors = merged.cursors().map((cursor) => ({
+					id: cursor.id(),
+					characterPosition: cursor.characterPosition()
+				}));
+
+				merged.free();
+
+				return {
+					text: resultText,
+					cursors: resultCursors
+				};
+			}
+		);
 	}
 
 	public async delete(path: RelativePath): Promise<void> {

frontend/sync-client/src/file-operations/filesystem-operations.ts

@@ -1,5 +1,15 @@
 import type { RelativePath } from "../persistence/database";
 
+export interface Cursor {
+	id: number;
+	characterPosition: number;
+}
+
+export interface TextWithCursors {
+	text: string;
+	cursors: Cursor[];
+}
+
 export interface FileSystemOperations {
 	// List all files that should be synced.
 	listAllFiles: () => Promise<RelativePath[]>;
@@ -13,7 +23,7 @@ export interface FileSystemOperations {
 	// Atomically update the content of a text file.
 	atomicUpdateText: (
 		path: RelativePath,
-		updater: (currentContent: string) => string
+		updater: (current: TextWithCursors) => TextWithCursors
 	) => Promise<string>;
 
 	// Get the size of a file in bytes.

frontend/sync-client/src/file-operations/safe-filesystem-operations.ts

@@ -1,5 +1,8 @@
 import type { RelativePath } from "../persistence/database";
-import type { FileSystemOperations } from "./filesystem-operations";
+import type {
+	FileSystemOperations,
+	TextWithCursors
+} from "./filesystem-operations";
 import type { Logger } from "../tracing/logger";
 import { Locks } from "../utils/locks";
 import { FileNotFoundError } from "./file-not-found-error";
@@ -44,7 +47,7 @@ export class SafeFileSystemOperations implements FileSystemOperations {
 
 	public async atomicUpdateText(
 		path: RelativePath,
-		updater: (currentContent: string) => string
+		updater: (current: TextWithCursors) => TextWithCursors
 	): Promise<string> {
 		this.logger.debug(`Atomically updating file '${path}'`);
 		return this.safeOperation(

frontend/sync-client/src/index.ts

@@ -8,7 +8,11 @@ export { Logger, LogLevel, LogLine } from "./tracing/logger";
 export { type SyncSettings } from "./persistence/settings";
 export { rateLimit } from "./utils/rate-limit";
 export type { RelativePath, StoredDatabase } from "./persistence/database";
-export type { FileSystemOperations } from "./file-operations/filesystem-operations";
+export type {
+	FileSystemOperations,
+	TextWithCursors,
+	Cursor
+} from "./file-operations/filesystem-operations";
 export type { PersistenceProvider } from "./persistence/persistence";
 
 export type { NetworkConnectionStatus } from "./sync-client";

frontend/sync-client/src/sync-operations/syncer.ts

@@ -266,6 +266,8 @@ export class Syncer {
 		wsUri.protocol = wsUri.protocol === "https" ? "wss" : "ws";
 		wsUri.pathname = `/vaults/${settings.vaultName}/ws`;
 
+		this.logger.info(`Connecting to WebSocket at ${wsUri.toString()}`);
+
 		if (
 			typeof globalThis !== "undefined" &&
 			typeof globalThis.WebSocket === "undefined"
@@ -288,6 +290,7 @@ export class Syncer {
 
 		// The JS WebSocket API doesn't support setting headers, so we have to send the token as a message
 		this.applyRemoteChangesWebSocket.onopen = (): void => {
+			this.logger.info("WebSocket connection opened");
 			this.applyRemoteChangesWebSocket?.send(settings.token);
 			this.webSocketStatusChangeListeners.forEach((listener) => {
 				listener();
@@ -476,7 +479,10 @@ export class Syncer {
 				.filter(
 					(remoteDocument) =>
 						allLocalFiles.includes(remoteDocument.relativePath) &&
-						!remoteDocument.isDeleted
+						!remoteDocument.isDeleted &&
+						this.database.getDocumentByDocumentId(
+							remoteDocument.documentId
+						) === undefined
 				)
 				.forEach((remoteDocument) => {
 					this.database.createNewEmptyDocument(

frontend/test-client/src/agent/mock-agent.ts

@@ -313,7 +313,10 @@ export class MockAgent extends MockClient {
 			`Decided to update file ${file} with ${content}`
 		);
 		this.doNotTouchWhileOffline.push(file);
-		await this.atomicUpdateText(file, (old) => old + ` ${content} `);
+		await this.atomicUpdateText(file, (old) => ({
+			text: old.text + ` ${content} `,
+			cursors: []
+		}));
 	}
 
 	private async deleteFileAction(files: RelativePath[]): Promise<void> {

frontend/test-client/src/agent/mock-client.ts

@@ -1,4 +1,4 @@
-import type { StoredDatabase } from "sync-client";
+import type { StoredDatabase, TextWithCursors } from "sync-client";
 import { assert } from "../utils/assert";
 import {
 	type RelativePath,
@@ -87,14 +87,14 @@ export class MockClient implements FileSystemOperations {
 
 	public async atomicUpdateText(
 		path: RelativePath,
-		updater: (currentContent: string) => string
+		updater: (currentContent: TextWithCursors) => TextWithCursors
 	): Promise<string> {
 		const file = this.localFiles.get(path);
 		if (!file) {
 			throw new Error(`File ${path} does not exist`);
 		}
 		const currentContent = new TextDecoder().decode(file);
-		const newContent = updater(currentContent);
+		const newContent = updater({ text: currentContent, cursors: [] }).text;
 		const newContentUint8Array = new TextEncoder().encode(newContent);
 		this.localFiles.set(path, newContentUint8Array);