import { Rule, RuleViolation } from './rule-interface';
/**
* MD014: Dollar signs used before commands without showing output
*
* This rule is triggered when there are dollar signs ($) before shell commands
* in a code block that doesn't show command output. The dollar signs are unnecessary
* in this case and should be removed.
*/
export const name = 'MD014';
export const description = 'Dollar signs used before commands without showing output';
/**
* Validate function to detect dollar signs used before commands without showing output
* @param lines Array of string lines to validate
* @param config Optional rule configuration
* @returns Array of rule violations
*/
export function validate(lines: string[], config?: any): RuleViolation[] {
const violations: RuleViolation[] = [];
let inCodeBlock = false;
let codeBlockStart = -1;
let codeBlockLanguage = '';
let codeBlockLines: Array<{line: string, lineNumber: number}> = [];
// Process the file line by line
for (let i = 0; i < lines.length; i++) {
const line = lines[i];
// Check for code block boundaries
if (line.trim().startsWith('```')) {
if (!inCodeBlock) {
// Start of code block
inCodeBlock = true;
codeBlockStart = i;
codeBlockLines = [];
// Extract the language if specified
codeBlockLanguage = line.trim().substring(3).trim().toLowerCase();
} else {
// End of code block - validate it
violations.push(...validateCodeBlock(codeBlockLines, codeBlockLanguage));
inCodeBlock = false;
}
} else if (inCodeBlock) {
// Inside code block - collect lines
codeBlockLines.push({line, lineNumber: i + 1});
}
}
return violations;
}
/**
* Validate a code block for dollar signs used before commands without showing output
*/
function validateCodeBlock(codeLines: Array<{line: string, lineNumber: number}>, language: string): RuleViolation[] {
const violations: RuleViolation[] = [];
// Only process shell/bash/sh code blocks or code blocks without a language
const relevantLanguages = ['bash', 'sh', 'shell', 'zsh', ''];
if (!relevantLanguages.includes(language)) {
return violations; // Return no violations if not a shell code block
}
// Check if this is a command-only code block (no output)
let allCommandsWithDollar = true;
let hasNonEmptyLines = false;
for (const {line} of codeLines) {
const trimmedLine = line.trim();
if (trimmedLine === '') continue; // Skip empty lines
hasNonEmptyLines = true;
if (!trimmedLine.startsWith('$ ')) {
allCommandsWithDollar = false;
break;
}
}
// If all lines are commands with dollar signs, report violations
if (allCommandsWithDollar && hasNonEmptyLines) {
for (const {line, lineNumber} of codeLines) {
const trimmedLine = line.trim();
if (trimmedLine.startsWith('$ ')) {
const dollarIndex = line.indexOf('$');
violations.push({
lineNumber,
details: `Dollar sign used before command without showing output: '${trimmedLine}'`,
range: [dollarIndex, 2] // $ and the space
});
}
}
}
return violations;
}
/**
* Fix code blocks by removing leading dollar signs from commands without output
* @param lines Array of string lines to fix
* @returns Fixed lines array with proper command formatting
*/
export function fix(lines: string[]): string[] {
const fixedLines: string[] = [];
let inCodeBlock = false;
let codeBlockLines: string[] = [];
let codeBlockLanguage = '';
// Process the file line by line
for (let i = 0; i < lines.length; i++) {
const line = lines[i];
// Check for code block boundaries
if (line.trim().startsWith('```')) {
if (!inCodeBlock) {
// Start of code block
inCodeBlock = true;
codeBlockLines = [];
// Extract the language if specified
codeBlockLanguage = line.trim().substring(3).trim().toLowerCase();
fixedLines.push(line); // Keep the opening fence
} else {
// End of code block - process and add fixed code block
fixedLines.push(...fixCodeBlock(codeBlockLines, codeBlockLanguage));
fixedLines.push(line); // Keep the closing fence
inCodeBlock = false;
}
} else if (inCodeBlock) {
// Inside code block - collect lines
codeBlockLines.push(line);
} else {
// Outside code block - keep as is
fixedLines.push(line);
}
}
// Handle case where file ends inside a code block
if (inCodeBlock) {
fixedLines.push(...codeBlockLines);
}
return fixedLines;
}
/**
* Process code block lines to remove dollar signs where appropriate
*/
function fixCodeBlock(codeLines: string[], language: string): string[] {
// Only process shell/bash/sh code blocks or code blocks without a language
const relevantLanguages = ['bash', 'sh', 'shell', 'zsh', ''];
if (!relevantLanguages.includes(language)) {
return codeLines; // Return unchanged if not a shell code block
}
// Check if this is a command-only code block (no output)
let allCommandsWithDollar = true;
let hasNonEmptyLines = false;
for (const line of codeLines) {
const trimmedLine = line.trim();
if (trimmedLine === '') continue; // Skip empty lines
hasNonEmptyLines = true;
if (!trimmedLine.startsWith('$ ')) {
allCommandsWithDollar = false;
break;
}
}
// If all lines are commands with dollar signs, remove them
if (allCommandsWithDollar && hasNonEmptyLines) {
return codeLines.map(line => {
const trimmedLine = line.trim();
if (trimmedLine.startsWith('$ ')) {
const leadingSpaces = line.match(/^\s*/)?.[0] || '';
return leadingSpaces + trimmedLine.substring(2);
}
return line;
});
}
// Otherwise, return unchanged
return codeLines;
}
/**
* Rule implementation for MD014
*/
export const rule: Rule = {
name,
description,
validate,
fix
};
export default rule;
