Swift lexer update for syntax highlight for macros and keywords

lib/rouge/lexers/swift.rb

@@ -26,6 +26,11 @@ class Swift < RegexLexer
         actor any associatedtype borrowing class consuming deinit distributed dynamic enum convenience extension fileprivate final func import indirect init internal lazy let macro nonisolated open optional package private protocol public required some static struct subscript typealias var
       )
 
+      # Swift Testing macros
+      testing_macros = Set.new %w(
+        expect require
+      )
+
       constants = Set.new %w(
         true false nil
       )
@@ -35,9 +40,13 @@ class Swift < RegexLexer
         @re_delim = "" # multi-line regex delimiter
       end
 
-      # beginning of line
+      # beginning of line      
       state :bol do
-        rule %r/#(?![#"\/]).*/, Comment::Preproc
+        # Handle Swift compiler directives
+        rule %r/#if\b.*/, Comment::Preproc
+        rule %r/#elseif\b.*/, Comment::Preproc  
+        rule %r/#else\b.*/, Comment::Preproc
+        rule %r/#endif\b.*/, Comment::Preproc                
 
         mixin :inline_whitespace
 
@@ -86,7 +95,13 @@ class Swift < RegexLexer
         rule %r{[\d]+(?:_\d+)*}, Num::Integer
 
         rule %r/@#{id}/, Keyword::Declaration
-        rule %r/##{id}/, Keyword
+        rule %r/#(#{id})/ do |m|
+          if testing_macros.include?(m[1])
+            token Name::Builtin
+          else
+            token Keyword
+          end
+        end
 
         rule %r/(private|internal)(\([ ]*)(\w+)([ ]*\))/ do |m|
           if m[3] == 'set'

spec/lexers/swift_spec.rb

@@ -58,5 +58,41 @@
                           ['Text', "\n\n"],
                           ['Comment.Multiline', separate_comment]
     end
+
+    it 'lexes Swift Testing macros as built-ins' do
+      # Test #expect macro
+      expect_code = '#expect(result == 42)'
+      assert_tokens_equal expect_code,
+                          ['Name.Builtin', '#expect'],
+                          ['Punctuation', '('],
+                          ['Name', 'result'],
+                          ['Text', ' '],
+                          ['Operator', '=='],
+                          ['Text', ' '],
+                          ['Literal.Number.Integer', '42'],
+                          ['Punctuation', ')']
+
+      # Test #require macro
+      require_code = '#require(value != nil)'
+      assert_tokens_equal require_code,
+                          ['Name.Builtin', '#require'],
+                          ['Punctuation', '('],
+                          ['Name', 'value'],
+                          ['Text', ' '],
+                          ['Operator', '!='],
+                          ['Text', ' '],
+                          ['Keyword.Constant', 'nil'],
+                          ['Punctuation', ')']
+    end
+
+    it 'lexes other # prefixed identifiers as keywords' do
+      # Test that non-testing macros are still lexed as keywords
+      other_macro = '#selector(buttonTapped)'
+      assert_tokens_equal other_macro,
+                          ['Keyword', '#selector'],
+                          ['Punctuation', '('],
+                          ['Name', 'buttonTapped'],
+                          ['Punctuation', ')']
+    end
   end
 end