{"id":13292,"library":"hcl-parser","title":"HCL Parser","description":"The `hcl-parser` package provides a JavaScript parser for HashiCorp Configuration Language (HCL). As of version 0.1.1, it functions as a direct transpilation of the official `hashicorp/hcl` Go library using GopherJS. This approach aims to offer high fidelity and compatibility with the authoritative HCL parsing logic, distinguishing it from independent JavaScript re-implementations. The library processes HCL input strings, returning a tuple-like result `[data, err]` where `data` is the parsed JSON object and `err` is a potential error object, mirroring Go's idiomatic error handling. Given its early version, the release cadence is likely irregular, and it's primarily designed for scenarios requiring precise HCL interpretation within JavaScript environments, particularly Node.js applications. This tool is beneficial for integrating with HashiCorp products where HCL configuration needs to be programmatically read or manipulated.","status":"active","version":"0.1.1","language":"javascript","source_language":"en","source_url":"https://github.com/anhldbk/hcl-parser#overview","tags":["javascript"],"install":[{"cmd":"npm install hcl-parser","lang":"bash","label":"npm"},{"cmd":"yarn add hcl-parser","lang":"bash","label":"yarn"},{"cmd":"pnpm add hcl-parser","lang":"bash","label":"pnpm"}],"dependencies":[],"imports":[{"note":"The library primarily uses ES Module syntax for imports.","wrong":"const { parse } = require('hcl-parser')","symbol":"parse","correct":"import { parse } from 'hcl-parser'"},{"note":"While primarily ESM, CommonJS `require` can be used in Node.js environments for backward compatibility.","wrong":"import { parse } from 'hcl-parser'","symbol":"parse","correct":"const { parse } = require('hcl-parser')"}],"quickstart":{"code":"import { parse } from \"hcl-parser\";\n\nconst input = `\n  resource \"aws_s3_bucket\" \"my_bucket\" {\n    bucket = \"my-unique-bucket-name\"\n    acl    = \"private\"\n\n    tags = {\n      Environment = \"dev\"\n      Project     = \"Acme\"\n    }\n\n    versioning {\n      enabled = true\n    }\n  }\n\n  variable \"region\" {\n    description = \"AWS region\"\n    type        = string\n    default     = \"us-east-1\"\n  }\n`;\n\nconst [data, err] = parse(input);\n\nif (err == null) {\n  console.log('Successfully parsed HCL:', JSON.stringify(data, null, 2));\n  // Example: access resource block\n  // console.log(data.resource.aws_s3_bucket.my_bucket.bucket);\n} else {\n  console.error('Error parsing HCL:', err);\n  // A more robust error handling might involve checking err.message and err.offset\n}","lang":"javascript","description":"Demonstrates how to parse a HCL string and handle both successful parsing and potential errors."},"warnings":[{"fix":"Be mindful of bundle size when using in browser environments. Always check the `err` return value after calling `parse` instead of relying on exceptions.","message":"This library is a direct transpilation from Go using GopherJS. This can lead to a larger bundle size compared to a native JavaScript implementation, which might be a concern for client-side applications. It also means error handling patterns mimic Go's `(result, err)` style rather than typical JavaScript `try-catch` blocks.","severity":"gotcha","affected_versions":">=0.1.0"},{"fix":"Pin the exact version (`npm install hcl-parser@0.1.1`) to ensure stability. Regularly review the project's GitHub releases for updates and potential breaking changes before upgrading.","message":"As of version 0.1.1, the library is in an early stage of development. While it provides core parsing functionality, the API might evolve, and new minor versions could introduce breaking changes without a major version increment. Production use should proceed with caution and thorough testing.","severity":"gotcha","affected_versions":">=0.1.0"},{"fix":"After parsing, `console.log` or `JSON.stringify` the `data` object for various HCL inputs to understand its exact structure and how to navigate it programmatically.","message":"The parser's output structure, being derived from the Go `hcl` library, might not always align perfectly with typical JavaScript object structures, especially for complex HCL constructs like blocks, attributes, and expressions. Developers should thoroughly inspect the `data` object's shape for their specific HCL inputs.","severity":"gotcha","affected_versions":">=0.1.0"}],"env_vars":null,"last_verified":"2026-04-19T00:00:00.000Z","next_check":"2026-07-18T00:00:00.000Z","problems":[{"fix":"Always check the `err` variable immediately after calling `parse`. Access `data` properties only if `err` is `null`.","cause":"Attempting to access properties of the `data` object without checking if an error occurred during parsing. If `err` is not null, `data` might be undefined or null.","error":"TypeError: Cannot read properties of undefined (reading 'resource') OR TypeError: data is null"},{"fix":"Ensure your project's `package.json` specifies `\"type\": \"module\"` for ESM, or use a CommonJS `require()` statement if your project is CJS-based. Use a build tool like Webpack or Rollup for browser compatibility if needed.","cause":"Mismatch between module system used for import (ESM `import`) and the environment's module system (CommonJS `require`), or vice versa.","error":"SyntaxError: Unexpected token 'export' (for ESM import in CJS environment) OR ReferenceError: require is not defined (for CJS require in ESM environment)"}],"ecosystem":"npm","meta_description":null,"install_score":null,"install_tag":null,"quickstart_score":null,"quickstart_tag":null,"pypi_latest":null,"cli_name":"","cli_version":null}