Make Template#freeze_string_literals? work correctly with Template#co…

…mpiled_path

This moves the frozen-string-literal magic comment to the first line
when writing the compiled template file, since otherwise it has no
effect and results in a verbose warning.

CHANGELOG.md

@@ -5,6 +5,7 @@
 * Remove deprecated support for CoffeeScriptTemplate.default_no_wrap{,=} (jeremyevans)
 * Remove deprecated support for RedCarpet 1.x (jeremyevans)
 * Remove deprecated support for Tilt.current_template (jeremyevans)
+* Make Template#freeze_string_literals? work correctly with Template#compiled_path (jeremyevans)
 
 ## 2.2.0 (2023-06-05)
 

lib/tilt/template.rb

@@ -351,7 +351,11 @@ def bind_compiled_method(method_source, offset, scope_class)
         path << ".rb"
 
         # Wrap method source in a class block for the scope, so constant lookup works
-        method_source = "class #{scope_class.name}\n#{method_source}\nend"
+        if freeze_string_literals?
+          method_source_prefix = "# frozen-string-literal: true\n"
+          method_source = method_source.sub(/\A# frozen-string-literal: true\n/, '')
+        end
+        method_source = "#{method_source_prefix}class #{scope_class.name}\n#{method_source}\nend"
 
         load_compiled_method(path, method_source)
       else

test/tilt_template_test.rb

@@ -139,6 +139,12 @@ def precompiled_template(locals)
     end
   end
 
+  _FrozenSourceGeneratingMockTemplate = Class.new(_SourceGeneratingMockTemplate) do
+    def freeze_string_literals?
+      true
+    end
+  end
+
   it "template_source with locals" do
     inst = _SourceGeneratingMockTemplate.new { |t| 'Hey #{name}!' }
     assert_equal "Hey Joe!", inst.render(Object.new, :name => 'Joe')
@@ -270,6 +276,32 @@ def precompiled_template(locals)
     end
   end
 
+  it "template with compiled_path and freezing string literals option" do
+    Dir.mktmpdir('tilt') do |dir|
+      base = File.join(dir, 'template')
+      inst = _FrozenSourceGeneratingMockTemplate.new { |t| 'Hey' }
+      inst.compiled_path = base
+
+      tempfile = "#{base}.rb"
+      assert_equal false, File.file?(tempfile)
+      assert_equal 'Hey', inst.render
+      assert_equal true, File.file?(tempfile)
+      assert_match(/\A# frozen-string-literal: true\nclass Object/, File.read(tempfile))
+
+      tempfile = "#{base}-1.rb"
+      assert_equal false, File.file?(tempfile)
+      assert_equal 'Hey', inst.render("")
+      assert_equal true, File.file?(tempfile)
+      assert_match(/\A# frozen-string-literal: true\nclass String/, File.read(tempfile))
+
+      tempfile = "#{base}-2.rb"
+      assert_equal false, File.file?(tempfile)
+      assert_equal 'Hey', inst.render(Tilt::Mapping.new)
+      assert_equal true, File.file?(tempfile)
+      assert_match(/\A# frozen-string-literal: true\nclass Tilt::Mapping/, File.read(tempfile))
+    end
+  end
+
   _CustomGeneratingMockTemplate = Class.new(_PreparingMockTemplate) do
     def precompiled_template(locals)
       data