Non-AST: instance variables in t(@v, scope: :lit)

Fixes #256

lib/i18n/tasks/scanners/pattern_with_scope_scanner.rb

@@ -34,12 +34,12 @@ def match_to_key(match, path, location)
 
     # parse expressions with literals and variable
     def first_argument_re
-      /(?: (?: #{literal_re} ) | #{variable_re} )/x
+      /(?: (?: #{literal_re} ) | #{expr_re} )/x
     end
 
     # strip literals, convert expressions to #{interpolations}
     def strip_literal(val)
-      if val =~ /\A\w/
+      if val =~ /\A[\w@]/
         "\#{#{val}}"
       else
         super(val)
@@ -54,17 +54,9 @@ def scope_arg_re
         ) (\[[^\n)%#]*\]|[^\n)%#,]*)/x
     end
 
-    # match code expression
-    # matches characters until , as a heuristic to parse scopes like [:categories, cat.key]
-    # can be massively improved by matching parenthesis
+    # match a limited subset of code expressions (no parenthesis, commas, etc)
     def expr_re
-      /[\w():"'.\s]+/x
-    end
-
-    # match variable key
-    # e.g: t(key, scope: 'scope') => t('scope.#{key}')
-    def variable_re
-      /\w+/
+      /[\w@.&|\s?!]+/
     end
 
     # extract literal or array of literals

spec/pattern_with_scope_scanner_spec.rb

@@ -32,6 +32,14 @@ def stub_source(scanner, source)
       expect(scanner.keys.map(&:key)).to eq(['scope.#{key}'])
     end
 
+    it 'matches a literal scope with an instance variable' do
+      stub_source scanner, '= t @key, scope: "scope"'
+      expect(scanner.keys.map(&:key)).to eq(['scope.#{@key}'])
+
+      stub_source scanner, '= t @key.m, scope: "scope"'
+      expect(scanner.keys.map(&:key)).to eq(['scope.#{@key.m}'])
+    end
+
     it 'matches an array of literals scope' do
       stub_source scanner, '= t :key, :scope => [:a, :b]'
       expect(scanner.keys.map(&:key)).to eq(['a.b.key'])