allow indefinite dot accessor as an object key (#209)

Author: kkozik-amplify

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## \[Unreleased\]
+
+### Fixed
+
+- Issue parsing dot-accessed attribute as an object key ([#209](https://github.com/amplify-education/python-hcl2/pull/209))
+
 ## \[7.0.0\] - 2025-03-27
 
 ### Added

hcl2/hcl2.lark

@@ -38,6 +38,7 @@ PLUS : "+"
 LPAR : "("
 RPAR : ")"
 COMMA : ","
+DOT : "."
 
 expr_term : LPAR new_line_or_comment? expression new_line_or_comment? RPAR
             | float_lit
@@ -74,8 +75,8 @@ EQ : /[ \t]*=(?!=|>)/
 tuple : "[" (new_line_or_comment* expression new_line_or_comment* ",")* (new_line_or_comment* expression)? new_line_or_comment* "]"
 object : "{" new_line_or_comment? (new_line_or_comment* (object_elem | (object_elem COMMA)) new_line_or_comment*)* "}"
 object_elem : object_elem_key ( EQ | ":") expression
-object_elem_key : float_lit | int_lit | identifier | STRING_LIT
-
+object_elem_key : float_lit | int_lit | identifier | STRING_LIT | object_elem_key_dot_accessor
+object_elem_key_dot_accessor : identifier (DOT identifier)+
 
 heredoc_template : /<<(?P<heredoc>[a-zA-Z][a-zA-Z0-9._-]+)\n?(?:.|\n)*?\n\s*(?P=heredoc)\n/
 heredoc_template_trim : /<<-(?P<heredoc_trim>[a-zA-Z][a-zA-Z0-9._-]+)\n?(?:.|\n)*?\n\s*(?P=heredoc_trim)\n/

hcl2/transformer.py

@@ -107,6 +107,9 @@ def object_elem(self, args: List) -> Dict:
         value = self.to_string_dollar(value)
         return {key: value}
 
+    def object_elem_key_dot_accessor(self, args: List) -> str:
+        return "".join(args)
+
     def object(self, args: List) -> Dict:
         args = self.strip_new_line_tokens(args)
         result: Dict[str, Any] = {}

test/helpers/terraform-config-json/s3.json

@@ -36,7 +36,11 @@
         "source": "s3_bucket_name",
         "name": "audit",
         "account": "${var.account}",
-        "region": "${var.region}"
+        "region": "${var.region}",
+        "providers": {
+          "aws.ue1": "${aws}",
+          "aws.uw2.attribute": "${aws.backup}"
+        }
       }
     }
   ]

test/helpers/terraform-config/s3.tf

@@ -28,4 +28,9 @@ module "bucket_name" {
   name    = "audit"
   account = var.account
   region  = var.region
+
+  providers = {
+    aws.ue1 = aws
+    aws.uw2.attribute = aws.backup
+  }
 }