merging and sorting hcl files

main.go

package main

import (
	"os"
	"sort"
	"strings"

	"github.com/hashicorp/hcl/v2"
	"github.com/hashicorp/hcl/v2/hclwrite"
)

func main() {
	// read files

	f1, err := os.ReadFile("f1.tf")
	check(err)

	f2, err := os.ReadFile("f2.tf")
	check(err)

	// parse files

	h1, d := hclwrite.ParseConfig(f1, "filename", hcl.InitialPos)
	if d.HasErrors() {
		panic(d.Error())
	}

	h2, d := hclwrite.ParseConfig(f2, "filename", hcl.InitialPos)
	if d.HasErrors() {
		panic(d.Error())
	}

	// merge all blocks together

	blocks := h1.Body().Blocks()
	blocks = append(blocks, h2.Body().Blocks()...)

	// sort blocks

	sort.Slice(blocks, func(i, j int) bool {
		return comparer(blocks[i]) < comparer(blocks[j])
	})

	// write out file

	out := hclwrite.NewFile()

	for _, b := range blocks {
		out.Body().AppendBlock(b)
		out.Body().AppendNewline()
	}

	fout, err := os.Create("out.tf")
	check(err)
	defer fout.Close()

	out.WriteTo(fout)
}

func check(err error) {
	if err != nil {
		panic(err)
	}
}

func comparer(block *hclwrite.Block) string {
	return block.Type() + strings.Join(block.Labels(), ".")
}