ESLint Analyzer

LLM-Ready SQL queries on ESLint errors in your project

A powerful tool for analyzing ESLint output with SQL queries, perfect for understanding code quality patterns and planning migration strategies.

Motivation

ESLint Analyzer is designed for:

• Error Analysis: Deep dive into your project's linting issues with SQL queries
• Statistics: Generate comprehensive reports on code quality metrics
• Migration Strategies: Plan ESLint adoption in large legacy projects by understanding error distribution
• Team Insights: Identify patterns and prioritize fixes across your codebase

Perfect for teams wanting to bring ESLint to existing projects or analyze code quality at scale.

Table Structure

The tool creates a DuckDB table with the following columns:

Column	Type	Description
file_path	TEXT	Path to the file containing the error/warning
rule_id	TEXT	ESLint rule identifier (e.g., no-unused-vars)
project_name	TEXT	Project name (derived from uploaded file name)
start_line	INTEGER	Line number where the issue starts
end_line	INTEGER	Line number where the issue ends
start_column	INTEGER	Column number where the issue starts
end_column	INTEGER	Column number where the issue ends
fixable	BOOLEAN	Whether the issue can be auto-fixed
deprecated	BOOLEAN	Whether the rule is deprecated
node_type	TEXT	AST node type where the issue occurs
severity	TEXT	Issue severity (error or warning)

Getting Started

1. Run the Application

# Using Docker
docker run -p 3000:3000 eslint-analyzer

# Or run locally
pnpm install
pnpm start

The application will be available at http://localhost:3000

2. Generate ESLint JSON Files

In your project(s), generate ESLint output in JSON format:

# Single project
eslint . --format json --output-file my-project.json

# For monorepos - create separate files for each package
eslint packages/frontend --format json --output-file frontend.json
eslint packages/backend --format json --output-file backend.json

Note: The filename (without extension) becomes the project_name in the database.

3. Upload and Process

1. Open the web interface at http://localhost:3000
2. Upload your JSON file(s) using the file picker
3. Optional: Enter your project's root directory name to convert absolute file paths to relative paths (removes usernames and system-specific paths)
4. Click "Process" to import the data
5. Multiple files can be uploaded for monorepo analysis

Useful Queries

Here are some LLM-made practical SQL queries to analyze your ESLint data:

Total Errors and Warnings Count

SELECT 
    severity,
    COUNT(*) as count
FROM eslint 
GROUP BY severity;

Top 10 Files with Most Issues

SELECT 
    file_path,
    COUNT(*) as total_issues,
    SUM(CASE WHEN severity = 'error' THEN 1 ELSE 0 END) as errors,
    SUM(CASE WHEN severity = 'warning' THEN 1 ELSE 0 END) as warnings
FROM eslint 
GROUP BY file_path 
ORDER BY total_issues DESC 
LIMIT 10;

Top 10 Files with Only Fixable Issues

SELECT 
    file_path,
    COUNT(*) as fixable_issues
FROM eslint 
WHERE fixable = true
GROUP BY file_path
HAVING COUNT(*) = (
    SELECT COUNT(*) 
    FROM eslint e2 
    WHERE e2.file_path = eslint.file_path
)
ORDER BY fixable_issues DESC 
LIMIT 10;

Files with Only Fixable Warnings

SELECT 
    file_path,
    COUNT(*) as fixable_warnings
FROM eslint 
WHERE severity = 'warning' 
    AND fixable = true
GROUP BY file_path
HAVING COUNT(*) = (
    SELECT COUNT(*) 
    FROM eslint e2 
    WHERE e2.file_path = eslint.file_path 
        AND e2.severity = 'warning'
)
ORDER BY fixable_warnings DESC;

Most Common Rules by Project

SELECT 
    project_name,
    rule_id,
    COUNT(*) as occurrences
FROM eslint 
GROUP BY project_name, rule_id 
ORDER BY project_name, occurrences DESC;

Contributing

Just kidding, there's no contribution process! 😄

But if you find this tool useful and want to improve it, send me an email.