twentyhq/twenty · error · JsoncParseError

JSONC parse errors:\n${errorMessages.join('\n')}

Error message

JSONC parse errors:\n${errorMessages.join('\n')}

What it means

Thrown by parseJsoncString when the jsonc-parser library reports one or more ParseError entries during parsing of a JSONC (JSON with Comments) string. Each error is formatted as 'Line {offset}: {error}' and all errors are joined with newlines. This wraps structured parse errors into a JsoncParseError exception with the underlying ParseError array attached.

Source

Thrown at packages/twenty-sdk/src/cli/utilities/file/file-jsonc.ts:37

}

export const parseJsoncString = (
  content: string,
  options: JsoncParseOptions = {},
): any => {
  const parseErrors: ParseError[] = [];

  const result = parseJsonc(content, parseErrors, {
    allowTrailingComma: options.allowTrailingComma ?? true,
    disallowComments: options.disallowComments ?? false,
    allowEmptyContent: options.allowEmptyContent ?? false,
  });

  if (parseErrors.length > 0) {
    const errorMessages = parseErrors.map(
      (error) => `Line ${error.offset}: ${error.error}`,
    );
    throw new JsoncParseError(
      `JSONC parse errors:\n${errorMessages.join('\n')}`,
      parseErrors,
    );
  }

  return result;
};

export const parseJsoncFile = async <T = object>(
  filePath: string,
  options: JsoncParseOptions = {},
): Promise<T> => {
  try {
    const content = await readFile(filePath, 'utf8');
    return parseJsoncString(content, options);
  } catch (error) {
    if (error instanceof JsoncParseError) {
      throw new JsoncParseError(error.message, error.parseErrors, filePath);

View on GitHub (pinned to 1f5dd2bbd2)

Solutions

1. Read the error message — it lists each parse error with its offset and description.
2. Open the file in a JSONC-aware editor (VS Code) which will highlight syntax errors visually.
3. Validate the file with an online JSONC validator or jsonc-parser directly.
4. If the error is about trailing commas, pass { allowTrailingComma: true } to parseJsoncString.
5. If the error is about comments, pass { disallowComments: false } (the default) or remove the comments.

Example fix

// before — file has a trailing comma
{ "name": "app", "version": "1.0", }

// after
{ "name": "app", "version": "1.0" }

import { parse as parseJsonc, type ParseError } from 'jsonc-parser';

const validateJsonc = (content: string): ParseError[] => {
  const errors: ParseError[] = [];
  parseJsonc(content, errors, { allowTrailingComma: true });
  return errors;
};

const errors = validateJsonc(fileContent);
if (errors.length > 0) {
  console.error('JSONC errors:', errors.map((e) => `offset ${e.offset}: ${e.error}`));
}

import { JsoncParseError } from '@/cli/utilities/file/file-jsonc';

const isJsoncParseError = (error: unknown): error is JsoncParseError => {
  return error instanceof JsoncParseError;
};

import { JsoncParseError, parseJsoncString } from '@/cli/utilities/file/file-jsonc';

try {
  const result = parseJsoncString(content);
} catch (error) {
  if (error instanceof JsoncParseError) {
    error.parseErrors.forEach((pe) => {
      console.error(`Offset ${pe.offset}: ${pe.error}`);
    });
    return;
  }
  throw error;
}

When it happens

Trigger: Calling parseJsoncString(content) where content has syntax errors: unclosed braces/brackets, invalid JSON tokens, trailing commas (if allowTrailingComma is false), or disallowed comments (if disallowComments is true). Empty content when allowEmptyContent is false.

Common situations: A tsconfig.json or other JSONC config file has a typo (missing comma, unclosed bracket). A trailing comma was left in strict mode. A comment was used in a context where comments are disallowed. The file was partially written (interrupted save) leaving truncated JSON.

Understand the failure class

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

Related errors

• defineApplication in ${configPath} must declare a universalI
• Failed to read file ${filePath}: ${error}
• Email and password are required
• No date fields for calendar
• File is not valid XML

AI-assisted analysis of twentyhq/twenty@1f5dd2bbd2 (2026-08-12). Data as JSON: /api/errors/64387127f50384a4. Report an issue: GitHub.