utils.ts — astro Source File

Source Code

import type { YAMLException } from 'js-yaml';
import type { TomlError } from 'smol-toml';
import type { ErrorPayload as ViteErrorPayload } from 'vite';
import type { SSRError } from '../../types/public/internal.js';

/**
 * Get the line and character based on the offset
 * @param offset The index of the position
 * @param text The text for which the position should be retrieved
 */
export function positionAt(
	offset: number,
	text: string,
): {
	line: number;
	column: number;
} {
	const lineOffsets = getLineOffsets(text);
	offset = Math.max(0, Math.min(text.length, offset));

	let low = 0;
	let high = lineOffsets.length;
	if (high === 0) {
		return {
			line: 0,
			column: offset,
		};
	}

	while (low <= high) {
		const mid = Math.floor((low + high) / 2);
		const lineOffset = lineOffsets[mid];

		if (lineOffset === offset) {
			return {
				line: mid,
				column: 0,
			};
		} else if (offset > lineOffset) {
			low = mid + 1;
		} else {
			high = mid - 1;
		}
	}

	// low is the least x for which the line offset is larger than the current offset
	// or array.length if no line offset is larger than the current offset
	const line = low - 1;
	return { line, column: offset - lineOffsets[line] };
}

function getLineOffsets(text: string) {
	const lineOffsets = [];
	let isLineStart = true;

	for (let i = 0; i < text.length; i++) {
		if (isLineStart) {
			lineOffsets.push(i);
			isLineStart = false;
		}
// ... (62 more lines)