django/tests/forms_tests/widget_tests/test_clearablefileinput.py

from django.core.files.uploadedfile import SimpleUploadedFile
from django.forms import ClearableFileInput, FileField, Form, MultiWidget

from .base import WidgetTest


class FakeFieldFile:
    """
    Quacks like a FieldFile (has a .url and string 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).
        """

        class StrangeFieldFile:
            url = "something?chapter=1&sect=2&copy=3&lang=en"

            def __str__(self):
                return """something<div onclick="alert('oops')">.jpg"""

        self.check_html(
            ClearableFileInput(),
            "my<div>file",
            StrangeFieldFile(),
            html=(
                """
                Currently:
                <a href="something?chapter=1&amp;sect=2&amp;copy=3&amp;lang=en">
                something&lt;div onclick=&quot;alert(&#x27;oops&#x27;)&quot;&gt;.jpg</a>
                <input type="checkbox" name="my&lt;div&gt;file-clear"
                    id="my&lt;div&gt;file-clear_id">
                <label for="my&lt;div&gt;file-clear_id">Clear</label><br>
                Change: <input type="file" name="my&lt;div&gt;file">
                """
            ),
        )

    def test_clear_input_renders_only_if_not_required(self):
        """
        A ClearableFileInput with is_required=True 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_render_disabled(self):
        self.check_html(
            self.widget,
            "myfile",
            FakeFieldFile(),
            attrs={"disabled": True},
            html=(
                'Currently: <a href="something">something</a>'
                '<input type="checkbox" name="myfile-clear" '
                'id="myfile-clear_id" disabled>'
                '<label for="myfile-clear_id">Clear</label><br>'
                'Change: <input type="file" name="myfile" disabled>'
            ),
        )

    def test_render_as_subwidget(self):
        """A ClearableFileInput as a subwidget of MultiWidget."""
        widget = MultiWidget(widgets=(self.widget,))
        self.check_html(
            widget,
            "myfile",
            [FakeFieldFile()],
            html=(
                """
            Currently: <a href="something">something</a>
            <input type="checkbox" name="myfile_0-clear" id="myfile_0-clear_id">
            <label for="myfile_0-clear_id">Clear</label><br>
            Change: <input type="file" name="myfile_0">
            """
            ),
        )

    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.assertIs(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)

    def test_html_does_not_mask_exceptions(self):
        """
        A ClearableFileInput should not mask exceptions produced while
        checking that it has a value.
        """

        class FailingURLFieldFile:
            @property
            def url(self):
                raise ValueError("Canary")

            def __str__(self):
                return "value"

        with self.assertRaisesMessage(ValueError, "Canary"):
            self.widget.render("myfile", FailingURLFieldFile())

    def test_url_as_property(self):
        class URLFieldFile:
            @property
            def url(self):
                return "https://www.python.org/"

            def __str__(self):
                return "value"

        html = self.widget.render("myfile", URLFieldFile())
        self.assertInHTML('<a href="https://www.python.org/">value</a>', html)

    def test_return_false_if_url_does_not_exists(self):
        class NoURLFieldFile:
            def __str__(self):
                return "value"

        html = self.widget.render("myfile", NoURLFieldFile())
        self.assertHTMLEqual(html, '<input name="myfile" type="file">')

    def test_use_required_attribute(self):
        # False when initial data exists. The file input is left blank by the
        # user to keep the existing, initial value.
        self.assertIs(self.widget.use_required_attribute(None), True)
        self.assertIs(self.widget.use_required_attribute("resume.txt"), False)

    def test_value_omitted_from_data(self):
        widget = ClearableFileInput()
        self.assertIs(widget.value_omitted_from_data({}, {}, "field"), True)
        self.assertIs(
            widget.value_omitted_from_data({}, {"field": "x"}, "field"), False
        )
        self.assertIs(
            widget.value_omitted_from_data({"field-clear": "y"}, {}, "field"), False
        )

    def test_fieldset(self):
        class TestForm(Form):
            template_name = "forms_tests/use_fieldset.html"
            field = FileField(widget=self.widget)
            with_file = FileField(widget=self.widget, initial=FakeFieldFile())
            clearable_file = FileField(
                widget=self.widget, initial=FakeFieldFile(), required=False
            )

        form = TestForm()
        self.assertIs(self.widget.use_fieldset, False)
        self.assertHTMLEqual(
            '<div><label for="id_field">Field:</label>'
            '<input id="id_field" name="field" type="file" required></div>'
            '<div><label for="id_with_file">With file:</label>Currently: '
            '<a href="something">something</a><br>Change:<input type="file" '
            'name="with_file" id="id_with_file"></div>'
            '<div><label for="id_clearable_file">Clearable file:</label>'
            'Currently: <a href="something">something</a><input '
            'type="checkbox" name="clearable_file-clear" id="clearable_file-clear_id">'
            '<label for="clearable_file-clear_id">Clear</label><br>Change:'
            '<input type="file" name="clearable_file" id="id_clearable_file"></div>',
            form.render(),
        )