Move more logic into sync-client

frontend/sync-client/src/utils/get-random-color.ts

@@ -0,0 +1,9 @@
+export function getRandomColor(name: string): string {
+	let hash = 0;
+	for (let i = 0; i < name.length; i++) {
+		hash = (hash << 5) - hash + name.charCodeAt(i);
+		hash |= 0; // Convert to 32bit integer
+	}
+	const normalised = hash / 0x7fffffff;
+	return `oklch(0.58 0.15 ${Math.round(Math.abs(normalised * 360))})`;
+}

frontend/sync-client/src/utils/line-and-column-to-position.test.ts

@@ -0,0 +1,44 @@
+import { describe, it } from "node:test";
+import assert from "node:assert";
+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);
+		assert.strictEqual(position, 3);
+	});
+
+	it("should return the correct position for the second line", () => {
+		const text = "Hello\nWorld";
+		const position = lineAndColumnToPosition(text, 1, 2);
+		assert.strictEqual(position, 8);
+	});
+
+	it("should return the correct position for an empty string", () => {
+		const text = "";
+		const position = lineAndColumnToPosition(text, 0, 0);
+		assert.strictEqual(position, 0);
+	});
+
+	it("with carrige return", () => {
+		assert.strictEqual(lineAndColumnToPosition("a\nb", 1, 1), 3);
+		assert.strictEqual(lineAndColumnToPosition("a\r\nb", 1, 1), 3);
+	});
+
+	it("should handle multi-line strings with varying lengths", () => {
+		const text = "Line1\nLongerLine2\nShort3";
+		const position = lineAndColumnToPosition(text, 2, 4);
+		assert.strictEqual(position, 22);
+	});
+
+	it("should throw an error if the line number is out of range", () => {
+		const text = "Line1\nLine2";
+		assert.throws(() => lineAndColumnToPosition(text, 3, 0));
+	});
+
+	it("should throw an error if the column number is out of range", () => {
+		const text = "Line1\nLine2";
+		assert.throws(() => lineAndColumnToPosition(text, 1, 10));
+	});
+});

frontend/sync-client/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.replace("\r", "").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/sync-client/src/utils/position-to-line-and-column.test.ts

@@ -0,0 +1,66 @@
+import { describe, test } from "node:test";
+import assert from "node:assert";
+import { positionToLineAndColumn } from "./position-to-line-and-column";
+
+describe("positionToLineAndColumn", () => {
+	test("converts position to line and column in multi-line text", () => {
+		const text = "ab\ncd\n";
+		assert.deepStrictEqual(positionToLineAndColumn(text, 0), {
+			line: 0,
+			column: 0
+		});
+		assert.deepStrictEqual(positionToLineAndColumn(text, 1), {
+			line: 0,
+			column: 1
+		});
+		assert.deepStrictEqual(positionToLineAndColumn(text, 2), {
+			line: 0,
+			column: 2
+		});
+		assert.deepStrictEqual(positionToLineAndColumn(text, 3), {
+			line: 1,
+			column: 0
+		});
+		assert.deepStrictEqual(positionToLineAndColumn(text, 4), {
+			line: 1,
+			column: 1
+		});
+		assert.deepStrictEqual(positionToLineAndColumn(text, 6), {
+			line: 2,
+			column: 0
+		});
+	});
+
+	test("with carrige returns", () => {
+		assert.deepStrictEqual(positionToLineAndColumn("a\nb", 3), {
+			line: 1,
+			column: 1
+		});
+
+		assert.deepStrictEqual(positionToLineAndColumn("a\r\nb", 3), {
+			line: 1,
+			column: 1
+		});
+	});
+
+	test("handles empty input", () => {
+		assert.deepStrictEqual(positionToLineAndColumn("", 0), {
+			line: 0,
+			column: 0
+		});
+	});
+
+	test("handles positions at the end of text", () => {
+		const text = "End";
+		assert.deepStrictEqual(positionToLineAndColumn(text, 3), {
+			line: 0,
+			column: 3
+		});
+	});
+
+	test("throws error for position out of range", () => {
+		const text = "Short text";
+		assert.throws(() => positionToLineAndColumn(text, 15));
+		assert.throws(() => positionToLineAndColumn(text, -1));
+	});
+});

frontend/sync-client/src/utils/position-to-line-and-column.ts

@@ -0,0 +1,36 @@
+/**
+ * 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
+ * @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");
+	}
+
+	text = text.replace("\r", "");
+
+	if (
+		position >
+		text.length + 1
+		// +1 to account for the cursor being after last character
+	) {
+		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;
+	const column = lines[lines.length - 1].length;
+
+	return { line, column };
+}