@lyubomir-popov/baseline-nudge-generator/src/error-handler.js

Automatic font metrics reader that generates baseline grid nudges for CSS typography systems

/**
 * Custom error classes for better error handling
 */

class FontFileError extends Error {
    constructor(message, fontPath) {
        super(message);
        this.name = 'FontFileError';
        this.fontPath = fontPath;
    }
}

class ConfigurationError extends Error {
    constructor(message, configPath) {
        super(message);
        this.name = 'ConfigurationError';
        this.configPath = configPath;
    }
}

class ValidationError extends Error {
    constructor(message, errors = []) {
        super(message);
        this.name = 'ValidationError';
        this.errors = errors;
    }
}

class FontMetricsError extends Error {
    constructor(message, fontPath) {
        super(message);
        this.name = 'FontMetricsError';
        this.fontPath = fontPath;
    }
}

/**
 * Format error message for CLI output
 * @param {Error} error - Error to format
 * @returns {string} Formatted error message
 */
function formatErrorForCLI(error) {
    let message = `❌ ${error.name}: ${error.message}`;

    switch (error.name) {
    case 'FontFileError':
        message += `\n   Font file: ${error.fontPath}`;
        message += '\n   💡 Supported formats: .woff2, .woff, .ttf, .otf';
        break;

    case 'ConfigurationError':
        message += `\n   Config file: ${error.configPath}`;
        message += '\n   💡 Run \'baseline-nudges init\' to create a sample config';
        break;

    case 'ValidationError':
        if (error.errors.length > 0) {
            message += '\n   Validation errors:';
            error.errors.forEach(err => {
                message += `\n     • ${err}`;
            });
        }
        break;

    case 'FontMetricsError':
        message += `\n   Font file: ${error.fontPath}`;
        message += '\n   💡 Try a different font format or check if the file is corrupted';
        break;
    }

    return message;
}

/**
 * Handle errors gracefully with user-friendly messages
 * @param {Error} error - Error to handle
 * @param {boolean} isCliContext - Whether this is called from CLI
 */
function handleError(error, isCliContext = false) {
    if (isCliContext) {
        console.error(formatErrorForCLI(error));
        process.exit(1);
    } else {
        throw error;
    }
}

/**
 * Wrap async functions with error handling
 * @param {Function} fn - Async function to wrap
 * @param {boolean} isCliContext - Whether this is CLI context
 * @returns {Function} Wrapped function
 */
function withErrorHandling(fn, isCliContext = false) {
    return async (...args) => {
        try {
            return await fn(...args);
        } catch (error) {
            handleError(error, isCliContext);
        }
    };
}

module.exports = {
    FontFileError,
    ConfigurationError,
    ValidationError,
    FontMetricsError,
    formatErrorForCLI,
    handleError,
    withErrorHandling
};