Legacy CommonJS YAML Parser

Common errors

• Error [ERR_REQUIRE_ESM]: require() of ES Module ... not supported. Instead change the require of ... to a dynamic import() call.

  cause Attempting to `require()` an ES Module or using `import` to load this CommonJS package in an ES Module context.
  fix This package is CommonJS-only. Ensure your project is configured for CommonJS or use a dynamic `import()` if bridging CJS and ESM. However, the fundamental fix is to migrate to a modern YAML parser that supports ESM.

• TypeError: yamlparser.parse is not a function

  cause The specific API for `yamlparser` is not officially documented. While `parse` is a common method for parsers, the module might export its parsing functionality differently (e.g., directly as a function `require('yamlparser')(yamlString)` or with a different method name).
  fix Due to the lack of documentation, you would typically need to inspect the source code to determine the correct function to call. However, the recommended fix is to switch to a well-documented and maintained YAML parsing library.

Warnings

• breaking The `yamlparser` package is entirely abandoned. Its GitHub repository was archived in December 2022, and it has not been updated since its initial release in 2013. Using this package introduces significant security vulnerabilities due to unpatched issues and lack of maintenance.
  Fix: Migrate to a currently maintained YAML parser like `js-yaml` or `yaml`.
• gotcha This package is strictly CommonJS (CJS) and does not support ES Modules (ESM). Attempting to import it using `import` statements in an ESM project will result in a runtime error.
  Fix: If stuck in a CJS environment, use `const yamlparser = require('yamlparser');`. For new projects, prefer modern parsers with ESM support.
• gotcha The package documentation is explicitly marked as 'ToDo' on npm, meaning there is no official API documentation. The exact methods and their behavior (e.g., `parse`, `load`, error handling) are not specified and must be inferred or found through source code analysis.
  Fix: Due to the undocumented API and abandoned status, it is strongly recommended not to use this package. If forced to use it, thorough testing of its behavior for all expected YAML inputs is necessary.
• gotcha The package explicitly states it 'does not intend to implement all the aspects formalized in the YAML specs,' focusing only on 'simply structured YAML files.' Complex YAML features (e.g., anchors, tags, specific data types) may not be supported or may be parsed incorrectly.
  Fix: Avoid using this parser for any YAML that utilizes advanced features. For full YAML specification compliance, use modern, actively maintained libraries.

Install

• npm install yamlparser npm
• yarn add yamlparser yarn
• pnpm add yamlparser pnpm

Imports

• parse
  wrong:

  import { parse } from 'yamlparser';

  correct:

  const yamlparser = require('yamlparser');
  const parsed = yamlparser.parse(yamlString);

  This package is strictly CommonJS. There is no official documentation for its API, but a `parse` method is inferred as the primary interface for parsing YAML strings. ESM imports are not supported.

Quickstart

Demonstrates how to import the `yamlparser` module using CommonJS `require` and parse a simple YAML string. Note the lack of error handling guarantees for malformed YAML due to limited spec support and undocumented API.

const yamlparser = require('yamlparser');

const yamlString = `
name: John Doe
age: 30
cities:
  - New York
  - London
active: true
`;

try {
  const data = yamlparser.parse(yamlString);
  console.log('Parsed YAML:', data);
  // Expected output: { name: 'John Doe', age: 30, cities: [ 'New York', 'London' ], active: true }
} catch (error) {
  console.error('Failed to parse YAML:', error.message);
}

// Example with invalid YAML (may throw an error or produce unexpected results depending on implementation)
const invalidYamlString = `
key: value
  another_key: indented_incorrectly
`;
try {
  const invalidData = yamlparser.parse(invalidYamlString);
  console.log('Parsed invalid YAML:', invalidData);
} catch (error) {
  console.error('Failed to parse invalid YAML as expected:', error.message);
}