From 70fd9d01fd076f4640da09fdfd53b310ec59a94c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bart=C5=82omiej=20Go=CC=81rny?=
 <bartlomiej.gorny@erlang-solutions.com>
Date: Wed, 12 Oct 2016 14:56:40 +0200
Subject: [PATCH] Don't strip leading underscore, allow it by regex (explicit
 over implicity, you know)

---
 src/elvis_rulesets.erl | 2 +-
 src/elvis_style.erl    | 9 +--------
 test/style_SUITE.erl   | 2 +-
 3 files changed, 3 insertions(+), 10 deletions(-)

diff --git a/src/elvis_rulesets.erl b/src/elvis_rulesets.erl
index dc139166..d59d745d 100644
--- a/src/elvis_rulesets.erl
+++ b/src/elvis_rulesets.erl
@@ -33,7 +33,7 @@ rules(erl_files) ->
   , {elvis_style, no_debug_call, #{ignore => [elvis, elvis_utils]}}
   , { elvis_style
     , variable_naming_convention
-    , #{regex => "^([A-Z][0-9a-zA-Z]*)$"}
+    , #{regex => "^_?([A-Z][0-9a-zA-Z]*)$"}
     }
   ];
 rules(makefiles) ->
diff --git a/src/elvis_style.erl b/src/elvis_style.erl
index 85032b0a..457dd557 100644
--- a/src/elvis_style.erl
+++ b/src/elvis_style.erl
@@ -636,14 +636,7 @@ no_nested_try_catch(Config, Target, _RuleConfig) ->
 %% Variables name
 check_variables_name(_Regex, []) -> [];
 check_variables_name(Regex, [Variable | RemainingVars]) ->
-    VariableName = atom_to_list(ktn_code:attr(name, Variable)),
-    %% Replace the leading underline (if any) in the variable name.
-    VariableNameStr = case length(VariableName) of
-        (N) when N > 1 ->
-            [_ | TempStr] = re:replace(VariableName, "^_?", ""),
-            binary_to_list(TempStr);
-        (_) -> VariableName
-    end,
+    VariableNameStr = atom_to_list(ktn_code:attr(name, Variable)),
     case re:run(VariableNameStr, Regex) of
         nomatch when VariableNameStr == "_" ->
             check_variables_name(Regex, RemainingVars);
diff --git a/test/style_SUITE.erl b/test/style_SUITE.erl
index f1dbada7..9119e32f 100644
--- a/test/style_SUITE.erl
+++ b/test/style_SUITE.erl
@@ -95,7 +95,7 @@ verify_variable_naming_convention(_Config) ->
     ElvisConfig = elvis_config:default(),
     SrcDirs = elvis_config:dirs(ElvisConfig),
 
-    RuleConfig = #{regex => "^([A-Z][0-9a-zA-Z]*)$"},
+    RuleConfig = #{regex => "^_?([A-Z][0-9a-zA-Z]*)$"},
 
     PathPass = "pass_variable_naming_convention.erl",
     {ok, FilePass} = elvis_test_utils:find_file(SrcDirs, PathPass),