Improve handling of comment nodes

kajiki/tests/test_xml.py

@@ -17,7 +17,7 @@
 import kajiki
 from kajiki import MockLoader, XMLTemplate, FileLoader, PackageLoader
 from kajiki.ir import TranslatableTextNode
-from kajiki.xml_template import _Compiler, _Parser, XMLTemplateCompileError
+from kajiki.xml_template import _Compiler, _Parser, XMLTemplateCompileError, XMLTemplateParseError
 
 DATA = os.path.join(os.path.dirname(__file__), 'data')
 
@@ -1034,11 +1034,25 @@ class TestMultipleChildrenInDOM(TestCase):
     def test_ok(self):
         XMLTemplate('<xml><!--  a  --><x>${1+1}</x></xml>')
 
-    def test_raise(self):
+    def test_comment(self):
+        res = XMLTemplate('<!-- a --><x>${1+1}</x>')().render()
+        assert res == '<x>2</x>'
+
+    def test_multiple_nodes(self):
         try:
-            XMLTemplate('<!-- a --><x>${1+1}</x>')
-        except XMLTemplateCompileError as e:
-            assert 'more than one children' in str(e), e
+            XMLTemplate('<!-- a --><x>${1+1}</x><y>${1+1}</y>')
+        except XMLTemplateParseError as e:
+            assert 'junk after document element' in str(e), e
+        else:
+            assert False, 'should have raised'
+
+    def test_only_comment(self):
+        try:
+            XMLTemplate('<!-- a -->')
+        except XMLTemplateParseError as e:
+            assert 'no element found' in str(e), e
+        else:
+            assert False, 'should have raised'
 
 
 class TestSyntaxErrorCallingWithTrailingParenthesis(TestCase):

kajiki/xml_template.py

@@ -17,7 +17,6 @@
 
 from . import ir
 from . import template
-from .template import KajikiSyntaxError
 from .ddict import defaultdict
 from .doctype import DocumentTypeDeclaration, extract_dtd
 from .entities import html5, unescape
@@ -116,10 +115,12 @@ def compile(self):
             registries of the compiler ``compile`` should
             never be called twice or might lead to unexpected results.
         """
-        if len(self.doc.childNodes) != 1:
-            raise XMLTemplateCompileError('more than one children in document',
+        templateNodes = [n for n in self.doc.childNodes if not isinstance(n, dom.Comment)]
+        if len(templateNodes) != 1:
+            raise XMLTemplateCompileError('expected a single root node in document',
                                           self.doc, self.filename, 0)
-        body = list(self._compile_node(self.doc.firstChild))
+
+        body = list(self._compile_node(templateNodes[0]))
         # Never emit doctypes on fragments
         if not self.is_fragment and not self.is_child:
             if self.doc._dtd: