Rewrote form widget tests as proper unittests.

This is preparation for landing the template-based widget rendering
patch and goes a long way to making these tests more useful for future
development. The old doctest heritage is strong here.

1 files changed, 126 insertions, 0 deletions

diff --git a/tests/forms_tests/widget_tests/test_clearablefileinput.py b/tests/forms_tests/widget_tests/test_clearablefileinput.py
new file mode 100644
index 0000000000..5a24a85e2a
--- /dev/null
+++ b/tests/forms_tests/widget_tests/test_clearablefileinput.py
@@ -0,0 +1,126 @@
+from django.core.files.uploadedfile import SimpleUploadedFile
+from django.forms import ClearableFileInput
+from django.utils import six
+from django.utils.encoding import python_2_unicode_compatible
+
+from .base import WidgetTest
+
+
+@python_2_unicode_compatible
+class FakeFieldFile(object):
+    """
+    Quacks like a FieldFile (has a .url and unicode representation), but
+    doesn't require us to care about storages etc.
+    """
+    url = 'something'
+
+    def __str__(self):
+        return self.url
+
+
+class ClearableFileInputTest(WidgetTest):
+    widget = ClearableFileInput()
+
+    def test_clear_input_renders(self):
+        """
+        A ClearableFileInput with is_required False and rendered with an
+        initial value that is a file renders a clear checkbox.
+        """
+        self.check_html(self.widget, 'myfile', FakeFieldFile(), html=(
+            """
+            Currently: <a href="something">something</a>
+            <input type="checkbox" name="myfile-clear" id="myfile-clear_id" />
+            <label for="myfile-clear_id">Clear</label><br />
+            Change: <input type="file" name="myfile" />
+            """
+        ))
+
+    def test_html_escaped(self):
+        """
+        A ClearableFileInput should escape name, filename, and URL
+        when rendering HTML (#15182).
+        """
+        @python_2_unicode_compatible
+        class StrangeFieldFile(object):
+            url = "something?chapter=1&sect=2&copy=3&lang=en"
+
+            def __str__(self):
+                return '''something<div onclick="alert('oops')">.jpg'''
+
+        widget = ClearableFileInput()
+        field = StrangeFieldFile()
+        output = widget.render('my<div>file', field)
+        self.assertNotIn(field.url, output)
+        self.assertIn('href="something?chapter=1&amp;sect=2&amp;copy=3&amp;lang=en"', output)
+        self.assertNotIn(six.text_type(field), output)
+        self.assertIn('something&lt;div onclick=&quot;alert(&#39;oops&#39;)&quot;&gt;.jpg', output)
+        self.assertIn('my&lt;div&gt;file', output)
+        self.assertNotIn('my<div>file', output)
+
+    def test_html_does_not_mask_exceptions(self):
+        """
+        A ClearableFileInput should not mask exceptions produced while
+        checking that it has a value.
+        """
+        @python_2_unicode_compatible
+        class FailingURLFieldFile(object):
+            @property
+            def url(self):
+                raise RuntimeError('Canary')
+
+            def __str__(self):
+                return 'value'
+
+        widget = ClearableFileInput()
+        field = FailingURLFieldFile()
+        with self.assertRaisesMessage(RuntimeError, 'Canary'):
+            widget.render('myfile', field)
+
+    def test_clear_input_renders_only_if_not_required(self):
+        """
+        A ClearableFileInput with is_required=False does not render a clear
+        checkbox.
+        """
+        widget = ClearableFileInput()
+        widget.is_required = True
+        self.check_html(widget, 'myfile', FakeFieldFile(), html=(
+            """
+            Currently: <a href="something">something</a> <br />
+            Change: <input type="file" name="myfile" />
+            """
+        ))
+
+    def test_clear_input_renders_only_if_initial(self):
+        """
+        A ClearableFileInput instantiated with no initial value does not render
+        a clear checkbox.
+        """
+        self.check_html(self.widget, 'myfile', None, html='<input type="file" name="myfile" />')
+
+    def test_clear_input_checked_returns_false(self):
+        """
+        ClearableFileInput.value_from_datadict returns False if the clear
+        checkbox is checked, if not required.
+        """
+        value = self.widget.value_from_datadict(
+            data={'myfile-clear': True},
+            files={},
+            name='myfile',
+        )
+        self.assertEqual(value, False)
+
+    def test_clear_input_checked_returns_false_only_if_not_required(self):
+        """
+        ClearableFileInput.value_from_datadict never returns False if the field
+        is required.
+        """
+        widget = ClearableFileInput()
+        widget.is_required = True
+        field = SimpleUploadedFile('something.txt', b'content')
+
+        value = widget.value_from_datadict(
+            data={'myfile-clear': True},
+            files={'myfile': field},
+            name='myfile',
+        )
+        self.assertEqual(value, field)