hcl-fmt

terraform fmt / tofu fmt compiled to WebAssembly, exposed as a JavaScript library.

Formats HCL/Terraform/OpenTofu source code using the exact same rules as tofu fmt: indentation, = alignment, "${expr}" → expr unwrapping, and legacy type normalization.

Note: This project was built with the assistance of Claude Code (Anthropic AI).

Requirements

• Go ≥ 1.23
• Node.js ≥ 18

Setup

The Go formatting logic is extracted from the OpenTofu source. Clone it once before building:

npm run clone-opentofu
go mod download

Build

npm run build

Usage

import { format } from './index.js'

const source = `
resource "aws_s3_bucket" "example" {
  bucket   =   "my-bucket"
  val = "\${var.name}"
}
`

const formatted = await format(source)
console.log(formatted)

format(source) returns a Promise<string> with the canonical form, or throws if the HCL is invalid.