Feature Request: HCL / Terraform (.tf) language support

[sachajw]

Summary

CodeGraph currently has no support for HCL/Terraform files (.tf, .tfvars, .hcl). Terraform is one of the most widely-used IaC tools, and many repos (especially infrastructure repos) consist entirely of .tf files. Currently these files are silently skipped during indexing with "No files found to index".

What's needed

A pre-compiled tree-sitter-hcl.wasm already exists in the npm ecosystem:

• Package: @tree-sitter-grammars/tree-sitter-hcl v1.2.0
• Ships: tree-sitter-hcl.wasm (92.5KB) and tree-sitter-terraform.wasm (92.5KB)
• License: MIT

Adding support would follow the exact same pattern as existing languages — three changes:

1. tree-sitter-wasms — vendor or reference the tree-sitter-hcl.wasm file
2. grammars.js — add .tf/.tfvars/.hcl to EXTENSION_MAP, add hcl to WASM_GRAMMAR_FILES
3. languages/hcl.js — create an HCL extractor (resource blocks, module blocks, data blocks, locals, variables, outputs, provider blocks, etc.) and register in languages/index.js

Key HCL/Terraform node types

The grammar exposes these block types that are relevant for code intelligence:

• block — generic HCL block (with labels for resource/module/data names)
• module_block — Terraform module references
• resource_declaration / data_declaration — resource and data source references
• variable_declaration / output_declaration / locals_declaration
• provider_declaration / terraform_declaration
• function_call — Terraform built-in functions

Example

resource "azurerm_resource_group" "example" {
  name     = "example-rg"
  location = "uksouth"
}

module "vnet" {
  source = "../modules/vnet"

  resource_group_name = azurerm_resource_group.example.name
}

data "azurerm_client_config" "current" {}

This would be extremely valuable for anyone using Claude Code with Terraform infrastructure repos. Happy to contribute a PR if you're open to it!