Add :line option for Haml::Engine

lib/haml.rb

@@ -890,6 +890,10 @@ $LOAD_PATH << dir unless $LOAD_PATH.include?(dir)
 #                           so it's really only useful for the user to assign
 #                           when dealing with Haml programatically.
 #
+# [<tt>:line</tt>]          The line offset of the Haml template being parsed.
+#                           This is useful for inline templates, similar to the last
+#                           argument to Kernel#eval
+#
 # [<tt>:filters</tt>]       A hash of filters that can be applied to Haml code.
 #                           The keys are the string names of the filters;
 #                           the values are references to the classes of the filters.

lib/haml/engine.rb

@@ -70,6 +70,7 @@ module Haml
           'textile' => Haml::Filters::Textile,
           'markdown' => Haml::Filters::Markdown },
         :filename => '(haml)',
+        :line => 1,
         :ugly => false,
         :format => :xhtml,
         :escape_html => false
@@ -106,7 +107,7 @@ END
 
       precompile
     rescue Haml::Error
-      $!.backtrace.unshift "#{@options[:filename]}:#{@index + $!.line_offset}" if @index
+      $!.backtrace.unshift "#{@options[:filename]}:#{@index + $!.line_offset + @options[:line] - 1}" if @index
       raise
     end
 
@@ -164,7 +165,7 @@ END
         @haml_buffer = buffer
       end
 
-      eval(@precompiled, scope, @options[:filename])
+      eval(@precompiled, scope, @options[:filename], @options[:line])
 
       # Get rid of the current buffer
       scope_object.instance_eval do
@@ -205,7 +206,7 @@ END
       end
 
       eval("Proc.new { |*_haml_locals| _haml_locals = _haml_locals[0] || {};" +
-           precompiled_with_ambles(local_names) + "}\n", scope, @options[:filename])
+           precompiled_with_ambles(local_names) + "}\n", scope, @options[:filename], @options[:line])
     end
 
     # Defines a method on +object+
@@ -247,7 +248,7 @@ END
       method = object.is_a?(Module) ? :module_eval : :instance_eval
 
       object.send(method, "def #{name}(_haml_locals = {}); #{precompiled_with_ambles(local_names)}; end",
-                  @options[:filename])
+                  @options[:filename], @options[:line])
     end
 
     private

test/haml/engine_test.rb

@@ -218,6 +218,22 @@ END
 
   # Options tests
 
+  def test_filename_and_line
+    begin
+      render("\n\n = abc", :filename => 'test', :line => 2)
+    rescue Exception => e
+      assert_kind_of Haml::SyntaxError, e
+      assert_match /test:4/, e.backtrace.first
+    end
+
+    begin
+      render("\n\n= 123\n\n= nil[]", :filename => 'test', :line => 2)
+    rescue Exception => e
+      assert_kind_of NoMethodError, e
+      assert_match /test:6/, e.backtrace.first
+    end
+  end
+
   def test_stop_eval
     assert_equal("", render("= 'Hello'", :suppress_eval => true))
     assert_equal("", render("- puts 'foo'", :suppress_eval => true))