Add form data helpers

docs/advanced_topics/testing.rst

@@ -44,14 +44,21 @@ WagtailPageTests
 
         .. code-block:: python
 
+            from wagtail.tests.utils.form_data import nested_form_data, streamfield
+
             def test_can_create_content_page(self):
                 # Get the HomePage
                 root_page = HomePage.objects.get(pk=2)
 
                 # Assert that a ContentPage can be made here, with this POST data
-                self.assertCanCreate(root_page, ContentPage, {
+                self.assertCanCreate(root_page, ContentPage, nested_form_data({
                     'title': 'About us',
-                    'body': 'Lorem ipsum dolor sit amet')
+                    'body': streamfield([
+                        ('text', 'Lorem ipsum dolor sit amet'),
+                    ])
+                }))
+
+        See :ref:`form_data_test_helpers` for a set of functions useful for constructing POST data.
 
     .. automethod:: assertAllowedParentPageTypes
 
@@ -79,3 +86,17 @@ WagtailPageTests
                 # A HomePage can have ContentPage and EventIndex children
                 self.assertAllowedParentPageTypes(
                     HomePage, {ContentPage, EventIndex})
+
+
+.. _form_data_test_helpers:
+
+Form data helpers
+=================
+
+.. automodule:: wagtail.tests.utils.form_data
+
+   .. autofunction:: nested_form_data
+
+   .. autofunction:: streamfield
+
+   .. autofunction:: inline_formset

wagtail/core/tests/test_tests.py

@@ -5,6 +5,7 @@ from wagtail.tests.testapp.models import (
     BusinessChild, BusinessIndex, BusinessNowherePage, BusinessSubIndex, EventIndex, EventPage,
     SimplePage, StreamPage)
 from wagtail.tests.utils import WagtailPageTests, WagtailTestUtils
+from wagtail.tests.utils.form_data import inline_formset, nested_form_data, streamfield
 
 
 class TestAssertTagInHTML(WagtailTestUtils, TestCase):
@@ -137,3 +138,60 @@ class TestWagtailPageTests(WagtailPageTests):
         self.assertAllowedParentPageTypes(BusinessIndex, all_but_business)
         with self.assertRaises(AssertionError):
             self.assertAllowedParentPageTypes(BusinessSubIndex, {BusinessSubIndex, BusinessIndex})
+
+
+class TestFormDataHelpers(TestCase):
+    def test_nested_form_data(self):
+        result = nested_form_data({
+            'foo': 'bar',
+            'parent': {
+                'child': 'field',
+            },
+        })
+        self.assertEqual(
+            result,
+            {'foo': 'bar', 'parent-child': 'field'}
+        )
+
+    def test_streamfield(self):
+        result = nested_form_data({'content': streamfield([
+            ('text', 'Hello, world'),
+            ('text', 'Goodbye, world'),
+        ])})
+
+        self.assertEqual(
+            result,
+            {
+                'content-count': '2',
+                'content-0-type': 'text',
+                'content-0-value': 'Hello, world',
+                'content-0-order': 0,
+                'content-0-deleted': '',
+                'content-1-type': 'text',
+                'content-1-value': 'Goodbye, world',
+                'content-1-order': 1,
+                'content-1-deleted': '',
+            }
+        )
+
+    def test_inline_formset(self):
+        result = nested_form_data({'lines': inline_formset([
+            {'text': 'Hello'},
+            {'text': 'World'},
+        ])})
+
+        self.assertEqual(
+            result,
+            {
+                'lines-TOTAL_FORMS': '2',
+                'lines-INITIAL_FORMS': '0',
+                'lines-MIN_NUM_FORMS': '0',
+                'lines-MAX_NUM_FORMS': '1000',
+                'lines-0-text': 'Hello',
+                'lines-0-ORDER': '0',
+                'lines-0-DELETE': '',
+                'lines-1-text': 'World',
+                'lines-1-ORDER': '1',
+                'lines-1-DELETE': '',
+            }
+        )

wagtail/tests/utils/form_data.py

@@ -0,0 +1,115 @@
+"""
+The ``assertCanCreate`` method requires page data to be passed in
+the same format that the page edit form would submit. For complex
+page types, it can be difficult to construct this data structure by hand;
+the ``wagtail.tests.utils.form_data`` module provides a set of helper
+functions to assist with this.
+"""
+
+
+def _nested_form_data(data):
+    if isinstance(data, dict):
+        items = data.items()
+    elif isinstance(data, list):
+        items = enumerate(data)
+
+    for key, value in items:
+        key = str(key)
+        if isinstance(value, (dict, list)):
+            for child_keys, child_value in _nested_form_data(value):
+                yield [key] + child_keys, child_value
+        else:
+            yield [key], value
+
+
+def nested_form_data(data):
+    """
+    Translates a nested dict structure into a flat form data dict
+    with hyphen-separated keys.
+
+    .. code-block:: python
+
+        nested_form_data({
+            'foo': 'bar',
+            'parent': {
+                'child': 'field',
+            },
+        })
+        # Returns: {'foo': 'bar', 'parent-child': 'field'}
+    """
+    return {'-'.join(key): value for key, value in _nested_form_data(data)}
+
+
+def streamfield(items):
+    """
+    Takes a list of (block_type, value) tuples and turns it in to
+    StreamField form data. Use this within a :func:`nested_form_data`
+    call, with the field name as the key.
+
+    .. code-block:: python
+
+        nested_form_data({'content': streamfield([
+            ('text', 'Hello, world'),
+        ])})
+        # Returns:
+        # {
+        #     'content-count': '1',
+        #     'content-0-type': 'text',
+        #     'content-0-value': 'Hello, world',
+        #     'content-0-order': 0,
+        #     'content-0-deleted': '',
+        # }
+    """
+    def to_block(index, item):
+        block, value = item
+        return {'type': block, 'value': value, 'deleted': '', 'order': index}
+    data_dict = {str(index): to_block(index, item)
+                 for index, item in enumerate(items)}
+    data_dict['count'] = str(len(data_dict))
+    return data_dict
+
+
+def inline_formset(items, initial=0, min=0, max=1000):
+    """
+    Takes a list of form data for an InlineFormset and translates
+    it in to valid POST data. Use this within a :func:`nested_form_data`
+    call, with the formset relation name as the key.
+
+    .. code-block:: python
+
+        nested_form_data({'lines': inline_formset([
+            {'text': 'Hello'},
+            {'text': 'World'},
+        ])})
+        # Returns:
+        # {
+        #     'lines-TOTAL_FORMS': '2',
+        #     'lines-INITIAL_FORMS': '0',
+        #     'lines-MIN_NUM_FORMS': '0',
+        #     'lines-MAX_NUM_FORMS': '1000',
+        #     'lines-0-text': 'Hello',
+        #     'lines-0-ORDER': '0',
+        #     'lines-0-DELETE': '',
+        #     'lines-1-text': 'World',
+        #     'lines-1-ORDER': '1',
+        #     'lines-1-DELETE': '',
+        # }
+    """
+    def to_form(index, item):
+        defaults = {
+            'ORDER': str(index),
+            'DELETE': '',
+        }
+        defaults.update(item)
+        return defaults
+
+    data_dict = {str(index): to_form(index, item)
+                 for index, item in enumerate(items)}
+
+    data_dict.update({
+        'TOTAL_FORMS': str(len(data_dict)),
+        'INITIAL_FORMS': str(initial),
+        'MIN_NUM_FORMS': str(min),
+        'MAX_NUM_FORMS': str(max),
+    })
+    return data_dict