Merge pull request #222 from dhunnapotha/fix_proper_escaping_of_dolla…

…r_v2

Fix for #207, Some escaped '$' characters are not unescaped

lib/dotenv/substitutions/variable.rb

@@ -10,11 +10,12 @@ module Substitutions
     module Variable
       class << self
         VARIABLE = /
-          (\\)?        # is it escaped with a backslash?
-          (\$)         # literal $
-          \{?          # allow brace wrapping
-          ([A-Z0-9_]+) # match the variable
-          \}?          # closing brace
+          (\\)?         # is it escaped with a backslash?
+          (\$)          # literal $
+          (?!\()        # shouldnt be followed by paranthesis
+          \{?           # allow brace wrapping
+          ([A-Z0-9_]+)? # optional alpha nums
+          \}?           # closing brace
         /xi
 
         def call(value, env)
@@ -23,8 +24,10 @@ def call(value, env)
 
             if match[1] == '\\'
               variable[1..-1]
-            else
+            elsif match[3]
               env.fetch(match[3]) { ENV[match[3]] }
+            else
+              variable
             end
           end
         end

spec/dotenv/parser_spec.rb

@@ -156,6 +156,15 @@ def env(string)
       expect(env('FOO="bar\rbaz"')).to eql("FOO" => "bar\rbaz")
     end
 
+    it "escape $ properly when no alphabets/numbers/_  are followed by it" do
+      expect(env("FOO=\"bar\\$ \\$\\$\"")).to eql("FOO" => "bar$ $$")
+    end
+
+    # echo bar $ -> prints bar $ in the shell
+    it "ignore $ when it is not escaped and no variable is followed by it" do
+      expect(env("FOO=\"bar $ \"")).to eql("FOO" => "bar $ ")
+    end
+
     # This functionality is not supported on JRuby or Rubinius
     if (!defined?(RUBY_ENGINE) || RUBY_ENGINE != "jruby") &&
        !defined?(Rubinius)