@hyrious/dup/src/jsonc.ts

Find duplicates in your lockfile

// From https://github.com/microsoft/vscode/blob/-/src/vs/base/common/jsonc.ts
// Licensed under the MIT License

// First group matches a double quoted string
// Second group matches a single quoted string
// Third group matches a multi line comment
// Forth group matches a single line comment
// Fifth group matches a trailing comma
const regexp = /("[^"\\]*(?:\\.[^"\\]*)*")|('[^'\\]*(?:\\.[^'\\]*)*')|(\/\*[^\/\*]*(?:(?:\*|\/)[^\/\*]*)*?\*\/)|(\/{2,}.*?(?:(?:\r?\n)|$))|(,\s*[}\]])/g;

/**
 * Strips single and multi line JavaScript comments from JSON
 * content. Ignores characters in strings BUT doesn't support
 * string continuation across multiple lines since it is not
 * supported in JSON.
 *
 * @param content the content to strip comments from
 * @returns the content without comments
*/
export function stripComments(content: string): string {
  return content.replace(regexp, function (match, _m1, _m2, m3, m4, m5) {
    // Only one of m1, m2, m3, m4, m5 matches
    if (m3) {
      // A block comment. Replace with nothing
      return '';
    } else if (m4) {
      // Since m4 is a single line comment is is at least of length 2 (e.g. //)
      // If it ends in \r?\n then keep it.
      const length = m4.length;
      if (m4[length - 1] === '\n') {
        return m4[length - 2] === '\r' ? '\r\n' : '\n';
      }
      else {
        return '';
      }
    } else if (m5) {
      // Remove the trailing comma
      return match.substring(1);
    } else {
      // We match a string
      return match;
    }
  });
}

/**
 * A drop-in replacement for JSON.parse that can parse
 * JSON with comments and trailing commas.
 *
 * @param content the content to strip comments from
 * @returns the parsed content as JSON
*/
export function parse<T>(content: string): T {
  const commentsStripped = stripComments(content);

  try {
    return JSON.parse(commentsStripped);
  } catch (error) {
    const trailingCommasStriped = commentsStripped.replace(/,\s*([}\]])/g, '$1');
    return JSON.parse(trailingCommasStriped);
  }
}