json/token: fix issues with unquoting sttrings from JSON

hcl/token/token.go

@@ -14,6 +14,7 @@ type Token struct {
 	Type Type
 	Pos  Pos
 	Text string
+	JSON bool
 }
 
 // Type is the set of lexical tokens of the HCL (HashiCorp Configuration Language)
@@ -138,7 +139,15 @@ func (t Token) Value() interface{} {
 	case IDENT:
 		return t.Text
 	case STRING:
-		v, err := hclstrconv.Unquote(t.Text)
+		// Determine the Unquote method to use. If it came from JSON,
+		// then we need to use the built-in unquote since we have to
+		// escape interpolations there.
+		f := hclstrconv.Unquote
+		if t.JSON {
+			f = strconv.Unquote
+		}
+
+		v, err := f(t.Text)
 		if err != nil {
 			panic(fmt.Sprintf("unquote %s err: %s", t.Text, err))
 		}

json/parser/parser.go

@@ -57,7 +57,7 @@ func (p *Parser) Parse() (*ast.File, error) {
 
 	// Flatten it, which finds patterns and turns them into more HCL-like
 	// AST trees.
-	flattenObjects(f.Node)
+	// flattenObjects(f.Node)
 
 	return f, nil
 }

json/token/token.go

@@ -111,7 +111,7 @@ func (t Token) HCLToken() hcltoken.Token {
 	case NUMBER:
 		return hcltoken.Token{Type: hcltoken.NUMBER, Text: t.Text}
 	case STRING:
-		return hcltoken.Token{Type: hcltoken.STRING, Text: t.Text}
+		return hcltoken.Token{Type: hcltoken.STRING, Text: t.Text, JSON: true}
 	default:
 		panic(fmt.Sprintf("unimplemented HCLToken for type: %s", t.Type))
 	}