import { Rule } from './rule-interface';
/**
* MD058: Tables should be surrounded by blank lines
*
* This rule is triggered when tables are not preceded or followed by a blank line.
* Surrounding tables with blank lines improves readability by visually separating
* them from other content.
*/
export const name = 'MD058';
export const description = 'Tables should be surrounded by blank lines';
/**
* Checks if a line appears to be part of a table
* Tables in markdown typically start with | or have a line with |---|---| pattern
* @param line The line to check
* @returns True if the line appears to be part of a table
*/
function isTableLine(line: string): boolean {
// Table lines either start with | or have | inside them with spaces/dashes in between
return line.trim().startsWith('|') || /^\s*\|.*\|/.test(line);
}
/**
* Checks if a line is a table divider row (contains only |, -, :, and spaces)
* @param line The line to check
* @returns True if the line is a table divider
*/
function isTableDivider(line: string): boolean {
return /^\s*\|[\s\-:\|]+\|\s*$/.test(line);
}
/**
* Fix tables by ensuring they have blank lines before and after
* @param lines Array of string lines to fix
* @returns Fixed lines array with blank lines added around tables
*/
export function fix(lines: string[]): string[] {
if (lines.length === 0) return lines;
const result: string[] = [];
let inTable = false;
let tableStartIndex = -1;
// Process each line to identify table boundaries
for (let i = 0; i < lines.length; i++) {
const line = lines[i];
const trimmedLine = line.trim();
// Check for table start
if (!inTable && isTableLine(line)) {
inTable = true;
tableStartIndex = result.length;
// Add a blank line before the table if needed
if (tableStartIndex > 0 && result[tableStartIndex - 1].trim() !== '') {
result.splice(tableStartIndex, 0, '');
tableStartIndex++;
}
}
// Add the current line
result.push(line);
// Check for table end
if (inTable && (i === lines.length - 1 || !isTableLine(lines[i + 1]))) {
inTable = false;
// Add a blank line after the table if needed
if (i < lines.length - 1 && lines[i + 1].trim() !== '') {
result.push('');
}
}
}
return result;
}
/**
* Rule implementation for MD058
*/
export const rule: Rule = {
name,
description,
fix
};
export default rule;
