1 files changed, 81 insertions, 0 deletions
diff --git a/bs4/tests/test_formatter.py b/bs4/tests/test_formatter.py
new file mode 100644
index 0000000..718989b
--- /dev/null
+++ b/bs4/tests/test_formatter.py
@@ -0,0 +1,81 @@
+from bs4.element import Tag
+from bs4.testing import SoupTest
+from bs4.formatter import (
+    Formatter,
+    HTMLFormatter,
+    XMLFormatter,
+)
+
+class TestFormatter(SoupTest):
+
+    def test_default_attributes(self):
+        # Test the default behavior of Formatter.attributes().
+        formatter = Formatter()
+        tag = Tag(name="tag")
+        tag['b'] = 1
+        tag['a'] = 2
+
+        # Attributes come out sorted by name. In Python 3, attributes
+        # normally come out of a dictionary in the order they were
+        # added.
+        self.assertEquals([('a', 2), ('b', 1)], formatter.attributes(tag))
+
+        # This works even if Tag.attrs is None, though this shouldn't
+        # normally happen.
+        tag.attrs = None
+        self.assertEquals([], formatter.attributes(tag))
+        
+    def test_sort_attributes(self):
+        # Test the ability to override Formatter.attributes() to,
+        # e.g., disable the normal sorting of attributes.
+        class UnsortedFormatter(Formatter):
+            def attributes(self, tag):
+                self.called_with = tag
+                for k, v in sorted(tag.attrs.items()):
+                    if k == 'ignore':
+                        continue
+                    yield k,v
+
+        soup = self.soup('<p cval="1" aval="2" ignore="ignored"></p>')
+        formatter = UnsortedFormatter()
+        decoded = soup.decode(formatter=formatter)
+
+        # attributes() was called on the <p> tag. It filtered out one
+        # attribute and sorted the other two.
+        self.assertEquals(formatter.called_with, soup.p)
+        self.assertEquals(u'<p aval="2" cval="1"></p>', decoded)
+
+    def test_empty_attributes_are_booleans(self):
+        # Test the behavior of empty_attributes_are_booleans as well
+        # as which Formatters have it enabled.
+        
+        for name in ('html', 'minimal', None):
+            formatter = HTMLFormatter.REGISTRY[name]
+            self.assertEquals(False, formatter.empty_attributes_are_booleans)
+
+        formatter = XMLFormatter.REGISTRY[None]
+        self.assertEquals(False, formatter.empty_attributes_are_booleans)
+
+        formatter = HTMLFormatter.REGISTRY['html5']
+        self.assertEquals(True, formatter.empty_attributes_are_booleans)
+
+        # Verify that the constructor sets the value.
+        formatter = Formatter(empty_attributes_are_booleans=True)
+        self.assertEquals(True, formatter.empty_attributes_are_booleans)
+
+        # Now demonstrate what it does to markup.
+        for markup in (
+                "<option selected></option>",
+                '<option selected=""></option>'
+        ):
+            soup = self.soup(markup)
+            for formatter in ('html', 'minimal', 'xml', None):
+                self.assertEquals(
+                    b'<option selected=""></option>',
+                    soup.option.encode(formatter='html')
+                )
+                self.assertEquals(
+                    b'<option selected></option>',
+                    soup.option.encode(formatter='html5')
+                )
+