Markdown Linter Fixer

Overview

Systematically fix linting issues in *.md files using markdownlint-cli2 through a structured workflow that diagnoses, fixes automatically where possible, and guides manual fixes when needed.

When to Use This Skill

Use this skill when:

• Fixing markdown linting errors in projects
• Standardizing markdown formatting across multiple files
• Addressing ordered list numbering issues (MD029)
• Preparing markdown documentation for quality standards
• Setting up markdown linting for the first time in a project

Workflow Process

Phase 1: Environment Setup & Prerequisites

Verify markdownlint-cli2 Installation

Check if markdownlint-cli2 is installed:

markdownlint-cli2 --version

If missing, install it globally via npm:

npm install -g markdownlint-cli2

Handle any permission or installation errors by suggesting:

• Local installation: npm install --save-dev markdownlint-cli2
• Using npx: npx markdownlint-cli2
• User-specific npm directory configuration

Configuration File Check

Look for existing markdown configuration files in the project root:

• .markdownlint-cli2.jsonc
• .markdownlint.json
• .markdownlint.yaml
• .markdownlint.yml
• .markdownlintrc

If none exist, create .markdownlint-cli2.jsonc with:

{
  "config": {
    "MD013": false
  },
  "ignores": []
}

This disables max line length warnings while keeping other rules active. The ignores array can be used to exclude specific files from linting (e.g., example files with intentional errors).

IMPORTANT - Configuration Policy:

• Do not ignore/hide linting errors by modifying .markdownlint-cli2.jsonc
• Only modify the ignores array based on:
  • Explicit user input or approval
  • Content from .gitignore file (files already ignored by git)
• Always ask the user before adding files to the ignore list
• Never suppress errors without user consent - fix them instead

Phase 2: Diagnostic Assessment

Initial Root-Level Scan

Run linter on root-level markdown files:

markdownlint-cli2 "*.md"

Document all issues found, including:

• Error codes (e.g., MD029, MD001, MD032)
• File names and line numbers
• Brief description of each issue

Comprehensive Recursive Scan

Scan all markdown files including subdirectories:

markdownlint-cli2 "**/*.md"

This includes files in directories like:

• docs/
• guides/
• Any other subdirectories containing markdown

Create a complete inventory of all issues across the project.

Phase 3: Issue Analysis

Categorize Errors by Type

Group all identified linting errors by error code:

• Track frequency of each error type
• Identify which errors are auto-fixable
• Flag special attention areas (especially MD029, which often requires understanding indentation issues)

Common error types:

• MD001: Heading levels should increment by one level at a time
• MD009: Trailing spaces
• MD010: Hard tabs
• MD012: Multiple consecutive blank lines
• MD029: Ordered list item prefix (requires special attention - often caused by improper indentation)
• MD032: Lists should be surrounded by blank lines
• MD047: Files should end with a single newline character

Document patterns such as:

• "Found 15 MD029 errors across 5 files"
• "MD032 appears in all documentation files"
• "MD029 errors primarily in files with code blocks within lists"

Phase 4: Automatic Fixes

Execute Auto-Fix

Run the auto-fix command to correct all auto-fixable issues:

markdownlint-cli2 "**/*.md" --fix

This command will:

• Automatically fix formatting issues where possible
• Preserve original content intent
• Modify files in place

Monitor for Issues

Watch for:

• Errors during the fix process
• Files that couldn't be modified (permissions)
• Any unexpected side effects

Document what was fixed automatically versus what remains.

Phase 5: Manual Fixes

Handle MD029 Issues

For remaining MD029 (ordered list item prefix) issues:

Load and consult references/MD029-Fix-Guide.md for detailed guidance on:

• Understanding the root cause: improper indentation of content between list items
• Proper 4-space indentation for code blocks within lists
• Indentation requirements for paragraphs, blockquotes, and nested content
• Common mistakes and how to avoid them
• Real-world examples showing before/after fixes
• Alternative solutions and when to use them

Key insight: MD029 errors often occur when code blocks, paragraphs, or other content between list items lack proper indentation (typically 4 spaces), causing markdown parsers to break list continuity.

Apply Manual Corrections

For issues not auto-fixed:

• Open affected files
• Apply fixes according to error type
• Maintain consistency with existing markdown style
• Verify fixes don't break content

Phase 6: Verification & Reporting

Re-run Linter

Confirm all issues are resolved:

markdownlint-cli2 "**/*.md"

If no errors appear, linting is complete. If errors remain, document them for additional manual fixes.

Generate Summary Report

Provide a comprehensive summary including:

1. Files Processed

   • Total count
   • List of files modified
   • Any files skipped or with errors

2. Issues Fixed by Type

   • Count of each error type fixed
   • Auto-fixed vs. manually fixed
   • Special notes on MD029 fixes

3. Remaining Issues (if any)

   • Error codes still present
   • Files requiring manual attention
   • Recommended next steps

4. Completion Status

   • Confirmation of successful completion, or
   • Clear explanation of remaining work needed
   • Any error details with suggested solutions

Key Principles

Preserve Content Intent

Always maintain the original meaning and structure of markdown content. Fix formatting without altering the author's intended message.

Configuration Awareness

Respect existing markdown configuration files. Don't override project-specific linting rules unless explicitly requested.

Progressive Fixing

Work from automatic fixes first, then manual fixes. This maximizes efficiency and reduces the risk of introducing errors.

Comprehensive Reporting

Provide clear, detailed reports at each phase so users understand:

• What was found
• What was fixed
• What remains (if anything)
• How to proceed

Error Handling

When encountering errors:

• Provide clear error messages
• Suggest alternative approaches
• Offer workarounds if primary methods fail
• Never proceed without user confirmation on alternative paths

Common Scenarios

Scenario 1: Clean Project Setup

User request: "Set up markdown linting for my documentation"

Process:

1. Install markdownlint-cli2
2. Create .markdownlint-cli2.jsonc with MD013 disabled
3. Run diagnostic scan
4. Execute auto-fix
5. Report results

Scenario 2: Fix Existing Issues

User request: "Fix all markdown linting errors in my project"

Process:

1. Verify markdownlint-cli2 available
2. Run comprehensive diagnostic
3. Categorize and report issues
4. Execute auto-fix
5. Guide through remaining manual fixes
6. Verify and report completion

Scenario 3: MD029-Focused Fixing

User request: "I have ordered list numbering issues in my markdown files" or "My lists with code blocks are showing MD029 errors"

Process:

1. Scan for MD029 errors specifically
2. Attempt auto-fix
3. For remaining issues, load MD029-Fix-Guide.md
4. Guide through proper 4-space indentation for code blocks and content within lists
5. Verify list continuity is maintained
6. Report completion

Resources

references/

MD029-Fix-Guide.md

Comprehensive guide for handling MD029 (ordered list item prefix) errors, focusing on the root cause: improper indentation. This reference provides:

• Explanation of why MD029 errors occur (content breaking list continuity)
• Proper indentation rules: 4 spaces for code blocks, paragraphs, and other content
• Indentation table showing requirements for different content types
• Common mistakes with clear ❌ wrong vs ✅ correct examples
• Real-world before/after examples
• Alternative solutions and when to use markdownlint-disable comments
• Best practices for maintaining list continuity
• Verification steps

Load this file when MD029 errors persist after auto-fix, or when user needs guidance on fixing ordered list issues. The guide is particularly valuable when lists contain code blocks or mixed content.

MD036-Guide.md

Comprehensive style guide for avoiding MD036 (no emphasis as heading) errors. This reference provides:

• Clear explanation of the MD036 rule and why it matters
• Wrong vs. correct examples showing bold text vs. proper heading syntax
• Heading level hierarchy guidelines (h1 through h6)
• Common violations to avoid when creating markdown files
• Best practices for using headings vs. bold text
• Quick checklist for markdown file creation and modification

Load this file when creating new markdown documentation or when encountering MD036 errors. Use as a reference to maintain consistent heading structure and avoid using bold text as heading substitutes.