Respect text encoding in !env tag

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](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [unreleased]
+
+### Fixed
+
+- `!env` tag now respects the `str_node_as_binary` option, so injected vars won't crash Mustache templates.
+
 ## [1.5.0] - 2023-07-05
 
 ### Added
@@ -40,5 +46,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Open sourcing of an existing internal project
 
 <!-- Markdown link dfn's -->
-[unreleased]: https://github.com/klarna-incubator/bec/compare/v1.0.0...HEAD
+[unreleased]: https://github.com/klarna-incubator/bec/compare/v1.5.0...HEAD
+[1.5.0]: https://github.com/klarna-incubator/bec/releases/tag/1.5.0
+[1.3.0]: https://github.com/klarna-incubator/bec/releases/tag/1.3.0
 [1.0.0]: https://github.com/klarna-incubator/bec/releases/tag/1.0.0

src/bec_node_env_variable.erl

@@ -17,7 +17,8 @@
 
 tags() -> [?TAG, "!env"].
 
-construct_token(#yamerl_constr{detailed_constr = Detailed},
+construct_token(#yamerl_constr{detailed_constr = Detailed,
+                               ext_options = Options},
                undefined,
                #yamerl_scalar{text = Text} = Token) ->
   case os:getenv(Text) of
@@ -28,11 +29,11 @@ construct_token(#yamerl_constr{detailed_constr = Detailed},
       Node = #yamerl_str{ module = ?MODULE
                         , tag = ?TAG
                         , pres = Pres
-                        , text = Value
+                        , text = encode_text(Value, Options)
                         },
       {finished, Node};
     Value ->
-      {finished, Value}
+      {finished, encode_text(Value, Options)}
   end;
 construct_token(_, _, Token) ->
   parsing_error(Token, "Invalid OS environment variable").
@@ -49,3 +50,10 @@ parsing_error(Token, Text) ->
     column = ?TOKEN_COLUMN(Token)
   },
   throw(Error).
+
+encode_text(Text, Options) ->
+  case proplists:get_value(str_node_as_binary, Options, false) of
+    false    -> Text;
+    true     -> unicode:characters_to_binary(Text);
+    Encoding -> unicode:characters_to_binary(Text, unicode, Encoding)
+  end.

test/bec_yml_SUITE.erl

@@ -14,6 +14,8 @@
 %% Testcases
 -export([ environment_variable_substitution/1
         , missing_environment_variable/1
+        , environment_variable_as_string/1
+        , environment_variable_as_binary/1
         ]).
 
 %%==============================================================================
@@ -65,9 +67,9 @@ environment_variable_substitution(_Config) ->
   Yml = <<"myval: !env TEST_VAL\n">>,
   try
     os:putenv("TEST_VAL", "abc"),
-    ?assertEqual([#{<<"myval">> => "abc"}], bec_yml:decode(Yml)),
+    ?assertEqual([#{<<"myval">> => <<"abc">>}], bec_yml:decode(Yml)),
     os:putenv("TEST_VAL", "xyz"),
-    ?assertEqual([#{<<"myval">> => "xyz"}], bec_yml:decode(Yml))
+    ?assertEqual([#{<<"myval">> => <<"xyz">>}], bec_yml:decode(Yml))
   after
     os:unsetenv("TEST_VAL")
   end.
@@ -77,3 +79,25 @@ missing_environment_variable(_Config) ->
   Yml = <<"myval: !env TEST_VAL\n">>,
   os:unsetenv("TEST_VAL"),
   ?assertThrow({yamerl_exception, _}, bec_yml:decode(Yml)).
+
+-spec environment_variable_as_string(config()) -> ok.
+environment_variable_as_string(_Config) ->
+  Yml = <<"myval: !env TEST_VAL\n">>,
+  Opts = [{map_node_format, map}],
+  try
+    os:putenv("TEST_VAL", "abc"),
+    ?assertEqual([#{"myval" => "abc"}], yamerl:decode(Yml, Opts))
+  after
+    os:unsetenv("TEST_VAL")
+  end.
+
+-spec environment_variable_as_binary(config()) -> ok.
+environment_variable_as_binary(_Config) ->
+  Yml = <<"myval: !env TEST_VAL\n">>,
+  Opts = [str_node_as_binary, {map_node_format, map}],
+  try
+    os:putenv("TEST_VAL", "abc"),
+    ?assertEqual([#{<<"myval">> => <<"abc">>}], yamerl:decode(Yml, Opts))
+  after
+    os:unsetenv("TEST_VAL")
+  end.