import { Rule } from './rule-interface';
/**
* MD052: Reference links and images should use a label that is defined
*
* This rule is triggered when reference links/images use a label that isn't defined.
* Our fix will convert undefined reference links to inline links when possible.
*/
export const name = 'MD052';
export const description = 'Reference links and images should use a label that is defined';
/**
* Fix undefined reference links by converting them to inline links
* @param lines Array of string lines to fix
* @returns Fixed lines array with valid reference links
*/
export function fix(lines: string[]): string[] {
// First, extract all reference link definitions
const definitions = extractReferenceLinkDefinitions(lines);
// Then fix links with undefined references
return lines.map(line => {
// Match reference links: [text][label] or [text][]
return line.replace(/\[([^\]]+)\]\[([^\]]*)\]/g, (match, text, label) => {
// For shortcut reference links [text][], the label is the text
const actualLabel = label || text;
// Check if the label is defined
if (definitions[actualLabel.toLowerCase()]) {
return match; // Label is defined, keep as is
}
// Label is undefined, convert to inline link if possible
// We'll use an empty URL as a placeholder, since we don't know the intended destination
return `[${text}]()`;
}).replace(/!\[([^\]]+)\]\[([^\]]*)\]/g, (match, text, label) => {
// Similar handling for reference images
const actualLabel = label || text;
if (definitions[actualLabel.toLowerCase()]) {
return match; // Label is defined, keep as is
}
// Convert to inline image with empty URL
return `![${text}]()`;
});
});
}
/**
* Extract reference link definitions from the document
* Returns a map of lowercase labels to their URLs
*/
function extractReferenceLinkDefinitions(lines: string[]): Record<string, string> {
const definitions: Record<string, string> = {};
// Regular expression to match reference link definitions: [label]: url
const definitionRegex = /^\s*\[([^\]]+)\]:\s*(\S+)(?:\s+(?:"([^"]+)"|'([^']+)'|\(([^)]+)\)))?$/;
for (const line of lines) {
const match = line.match(definitionRegex);
if (match) {
const label = match[1].trim();
const url = match[2];
// Store the definition (case-insensitive)
definitions[label.toLowerCase()] = url;
}
}
return definitions;
}
/**
* Rule implementation for MD052
*/
export const rule: Rule = {
name,
description,
fix
};
export default rule;
