feat: do not treat as traversal but treat as raw attribute

api/hcl_parser.go

@@ -8,7 +8,6 @@ import (
 	"strings"
 
 	"github.com/hashicorp/hcl/v2"
-	"github.com/hashicorp/hcl/v2/hclsyntax"
 	"github.com/hashicorp/hcl/v2/hclwrite"
 )
 
@@ -52,20 +51,8 @@ func (p HCLParser) ConcatFile(baseDir string, pathes []string) (*hclwrite.File,
 }
 
 func setBodyAttribute(target *hclwrite.Body, name string, attr *hclwrite.Attribute) (*hclwrite.Body, error) {
-	// Parse the attribute's tokens into an expression
-	// filename is used only for diagnostic messages. so it can be placeholder string.
-	expr, diags := hclsyntax.ParseExpression(attr.Expr().BuildTokens(nil).Bytes(), "overlays", hcl.InitialPos)
-	if diags.HasErrors() {
-		return nil, diags
-	}
-
-	// Evaluate the expression to get a cty.Value
-	val, diags := expr.Value(nil)
-	if diags.HasErrors() {
-		return nil, diags
-	}
-
-	target.SetAttributeValue(name, val)
+	tokens := attr.Expr().BuildTokens(nil)
+	target.SetAttributeRaw(name, tokens)
 
 	return target, nil
 }
@@ -109,6 +96,7 @@ func mergeBlocks(base *hclwrite.Body, overlay *hclwrite.Body) (*hclwrite.Body, e
 	for _, overlayBlock := range overlayBlocks {
 		joinedLabel := strings.Join(overlayBlock.Labels(), "_")
 		blockType := overlayBlock.Type()
+		fmt.Printf("[debug] processing overlay blockType, joinedLabel: %v, %v\n", blockType, joinedLabel)
 		switch blockType {
 		case "provider", "resource", "data", "module", "terraform":
 			if tmpBlock, ok := tmpBlocks[blockType][joinedLabel]; ok {
@@ -149,8 +137,10 @@ func mergeBlocks(base *hclwrite.Body, overlay *hclwrite.Body) (*hclwrite.Body, e
 		base.AppendNewline()
 	}
 
-	for _, tmpBlock := range tmpBlocks {
-		for _, block := range tmpBlock {
+	for blockType, tmpBlock := range tmpBlocks {
+		fmt.Printf("[debug] processing blockType: %v\n", blockType)
+		for joinedLabel, block := range tmpBlock {
+			fmt.Printf("[debug] processing joinedLabel: %v\n", joinedLabel)
 			base.AppendBlock(block)
 		}
 		base.AppendNewline()
@@ -181,9 +171,10 @@ func mergeBlock(baseBlock *hclwrite.Block, overlayBlock *hclwrite.Block) (*hclwr
 	sort.Strings(sortedNames)
 
 	for _, name := range sortedNames {
+		fmt.Printf("[debug] processing name, value: %v, %v\n", name, tmpAttributes[name])
 		_, err := setBodyAttribute(resultBlockBody, name, tmpAttributes[name])
 		if err != nil {
-			return resultBlock, err
+			return nil, err
 		}
 	}
 

api/hcl_parser_test.go

@@ -82,10 +82,12 @@ resource "aws_s3_bucket" "bar" {
 			}
 
 			hclFile, err := parser.ConcatFile(dir, fileNames)
-			if (err != nil) || tt.wantErr {
+			if err != nil && !tt.wantErr {
 				t.Errorf("%q. ConcatFile() error = %v, wantErr %v", tt.name, err, tt.wantErr)
+				assert.Fail(t, "unexpected error")
+			} else {
+				assert.Equal(t, tt.expect, string(hclwrite.Format(hclFile.Bytes())))
 			}
-			assert.Equal(t, tt.expect, string(hclwrite.Format(hclFile.Bytes())))
 		})
 	}
 }
@@ -139,6 +141,28 @@ func TestMergeFileBlocks(t *testing.T) {
     values = ["hvm"]
   }
 }
+`,
+			wantErr: false,
+		},
+		{
+			name:    "data source and resource",
+			base:    []string{"base/data_and_resource.tf"},
+			overlay: []string{"overlay/data_and_resource.tf"},
+			expect: `data "aws_ami" "ubuntu" {
+  most_recent = false
+  filter {
+    name   = "name"
+    values = ["ubuntu/images/hvm-ssd/ubuntu-focal-20.04-amd64-server-*"]
+  }
+}
+resource "aws_instance" "web" {
+  ami               = data.aws_ami.ubuntu.id
+  availability_zone = "ap-northeast-1a"
+  instance_type     = "t3.large"
+  tags = {
+    Name = "HelloWorld"
+  }
+}
 `,
 			wantErr: false,
 		},
@@ -159,10 +183,12 @@ func TestMergeFileBlocks(t *testing.T) {
 			}
 
 			result, err := parser.MergeFileBlocks(baseHCL, overlayHCL)
-			if (err != nil) || tt.wantErr {
+			if err != nil && !tt.wantErr {
 				t.Errorf("MergeFileBlocks() error = %v, wantErr %v", err, tt.wantErr)
+				assert.Fail(t, "unexpected error")
+			} else {
+				assert.Equal(t, tt.expect, regexpFormatNewLines.ReplaceAllString(string(hclwrite.Format(result.Bytes())), "\n"))
 			}
-			assert.Equal(t, tt.expect, regexpFormatNewLines.ReplaceAllString(string(hclwrite.Format(result.Bytes())), "\n"))
 		})
 	}
 }

test/base/data_and_resource.tf

@@ -0,0 +1,15 @@
+data "aws_ami" "ubuntu" {
+  filter {
+    name   = "name"
+    values = ["ubuntu/images/hvm-ssd/ubuntu-focal-20.04-amd64-server-*"]
+  }
+}
+
+resource "aws_instance" "web" {
+  ami           = data.aws_ami.ubuntu.id
+  instance_type = "t3.micro"
+
+  tags = {
+    Name = "HelloWorld"
+  }
+}

test/overlay/data_and_resource.tf

@@ -0,0 +1,8 @@
+data "aws_ami" "ubuntu" {
+  most_recent = false
+}
+
+resource "aws_instance" "web" {
+  instance_type     = "t3.large"
+  availability_zone = "ap-northeast-1a"
+}