/**
* Tolerant JSON parser with multi-stage fallback strategy
* Matches the Python version's resilience for malformed JSON
*/
export interface JsonParseResult<T = any> {
data?: T;
error?: string;
}
/**
* Parse JSON with tolerance for common formatting issues
*/
export function parseJsonTolerant<T = any>(content: string): JsonParseResult<T> {
// Strategy 1: Standard JSON.parse
try {
const data = JSON.parse(content);
return { data };
} catch (error) {
// Continue to fallback strategies
}
// Strategy 2: Strip JavaScript-style comments (preserving URLs)
try {
const withoutComments = stripComments(content);
const data = JSON.parse(withoutComments);
return { data };
} catch (error) {
// Continue to fallback strategies
}
// Strategy 3: Remove trailing commas
try {
const withoutTrailingCommas = removeTrailingCommas(content);
const data = JSON.parse(withoutTrailingCommas);
return { data };
} catch (error) {
// Continue to fallback strategies
}
// Strategy 4: Combined - strip comments AND remove trailing commas
try {
const cleaned = removeTrailingCommas(stripComments(content));
const data = JSON.parse(cleaned);
return { data };
} catch (error) {
return {
error: `Failed to parse JSON after all attempts: ${error}`,
};
}
}
/**
* Strip JavaScript-style line comments from JSON
* Preserves http:// and https:// URLs
*/
function stripComments(content: string): string {
const lines = content.split('\n');
const cleanedLines = lines.map((line) => {
// Find // that is not part of http:// or https://
const match = line.match(/^(.*?)(?<!:)\/\/(.*)$/);
if (match && !line.includes('http://') && !line.includes('https://')) {
return match[1]; // Return everything before //
}
return line;
});
return cleanedLines.join('\n');
}
/**
* Remove trailing commas from JSON
* Handles commas before } and ]
*/
function removeTrailingCommas(content: string): string {
// Remove trailing commas before closing braces/brackets
// Pattern: comma followed by optional whitespace and closing brace/bracket
return content
.replace(/,(\s*[}\]])/g, '$1')
.replace(/,(\s*\n\s*[}\]])/g, '$1');
}
/**
* Parse JSON file content with tolerance
*/
export async function parseJsonFile<T = any>(
filePath: string,
content: string
): Promise<JsonParseResult<T>> {
const result = parseJsonTolerant<T>(content);
if (result.error) {
return {
error: `Error parsing ${filePath}: ${result.error}`,
};
}
return result;
}
