From 1059cf4d81ef96b593d94e342dfcef5bbfafe98c Mon Sep 17 00:00:00 2001 From: Tom Byers Date: Fri, 22 Jan 2021 15:40:28 +0000 Subject: [PATCH] Remove extend_params in favour of merge_jsonlike A comment on the pull request for this branch pointed out that it's not clear why the 'items' list is deleted and then reassigned in extend_params: https://github.com/alphagov/notifications-admin/pull/3770#pullrequestreview-573067465 The simple reason is that we want to use merge_jsonlike to merge params and param_extensions (passed in as extensions) but merge_jsonlike doesn't merge lists correctly. I realised that if we just make merge_jsonlike merge lists correctly, we can use it for everything extend_params does. This commit does that, and replaces all calls to extend_params with merge_jsonlike. Because extend_params is used across many form field classes, and so many pages, I took the following precautions after making those changes: 1. found every use of param_extensions 2. looked at the merges onto params that each would cause and deduped them to a final list of 6(!) 3. tested pages containing fields from that list 4. added new testcases to the merge_jsonlike tests for any merges that exist in our codebase but not in our tests --- app/main/forms.py | 39 ++++++--------------------------------- tests/app/test_utils.py | 10 +++++++++- 2 files changed, 15 insertions(+), 34 deletions(-) diff --git a/app/main/forms.py b/app/main/forms.py index 92333c47d..cd4617f31 100644 --- a/app/main/forms.py +++ b/app/main/forms.py @@ -637,33 +637,6 @@ class RegisterUserFromOrgInviteForm(StripWhitespaceForm): auth_type = HiddenField('auth_type', validators=[DataRequired()]) -def extend_params(params, extensions): - items = None - param_items = len(params['items']) if 'items' in params else 0 - - # split items off from params to make it a pure dict - if 'items' in extensions: - items = extensions['items'] - del extensions['items'] - - # merge dicts - merge_jsonlike(params, extensions) - - # tidy up - extensions['items'] = items - - # merge items - if items: - if 'items' not in params: - params['items'] = extensions['items'] - else: - for idx, _item in enumerate(extensions['items']): - if idx >= param_items: - params['items'].append(extensions['items'][idx]) - else: - params['items'][idx].update(extensions['items'][idx]) - - def govuk_checkbox_field_widget(self, field, param_extensions=None, **kwargs): # error messages @@ -695,11 +668,11 @@ def govuk_checkbox_field_widget(self, field, param_extensions=None, **kwargs): # extend default params with any sent in during instantiation if self.param_extensions: - extend_params(params, self.param_extensions) + merge_jsonlike(params, self.param_extensions) # add any sent in though use in templates if param_extensions: - extend_params(params, param_extensions) + merge_jsonlike(params, param_extensions) return Markup( render_template('forms/fields/checkboxes/macro.njk', params=params)) @@ -751,11 +724,11 @@ def govuk_checkboxes_field_widget(self, field, wrap_in_collapsible=False, param_ # extend default params with any sent in during instantiation if self.param_extensions: - extend_params(params, self.param_extensions) + merge_jsonlike(params, self.param_extensions) # add any sent in though use in templates if param_extensions: - extend_params(params, param_extensions) + merge_jsonlike(params, param_extensions) if wrap_in_collapsible: @@ -805,11 +778,11 @@ def govuk_radios_field_widget(self, field, param_extensions=None, **kwargs): # extend default params with any sent in during instantiation if self.param_extensions: - extend_params(params, self.param_extensions) + merge_jsonlike(params, self.param_extensions) # add any sent in though use in templates if param_extensions: - extend_params(params, param_extensions) + merge_jsonlike(params, param_extensions) return Markup( render_template('components/radios/template.njk', params=params)) diff --git a/tests/app/test_utils.py b/tests/app/test_utils.py index b869e9a6a..b198cf1b0 100644 --- a/tests/app/test_utils.py +++ b/tests/app/test_utils.py @@ -616,6 +616,8 @@ def test_get_sample_template_returns_template(template_type): ({"a": {"b": "c"}}, {"a": {"e": "f"}}, {"a": {"b": "c", "e": "f"}}), # same key in both dicts, value is a string, destination supercedes source: ({"a": "b"}, {"a": "c"}, {"a": "c"}), + # nested dict added to new key of dict, additive behaviour: + ({"a": "b"}, {"c": {"d": "e"}}, {"a": "b", "c": {"d": "e"}}), # lists with same length but different items, destination supercedes source: (["b", "c", "d"], ["b", "e", "f"], ["b", "e", "f"]), # lists in dicts behave as top level lists @@ -626,8 +628,14 @@ def test_get_sample_template_returns_template(template_type): ([{"b": "c"}], [{"b": "c"}], [{"b": "c"}]), # if dicts in lists have different values, they are not merged ([{"b": "c"}], [{"b": "e"}], [{"b": "e"}]), + # if nested dicts in lists have different keys, additive behaviour + ([{"b": "c"}], [{"d": {"e": "f"}}], [{"b": "c", "d": {"e": "f"}}]), # merge a dict with a null object returns that dict (does not work the other way round) - ({"a": {"b": "c"}}, None, {"a": {"b": "c"}}) + ({"a": {"b": "c"}}, None, {"a": {"b": "c"}}), + # double nested dicts, new adds new Boolean key: value, additive behaviour + ({"a": {"b": {"c": "d"}}}, {"a": {"b": {"e": True}}}, {"a": {"b": {"c": "d", "e": True}}}), + # double nested dicts, both have same key, different values, destination supercedes source + ({"a": {"b": {"c": "d"}}}, {"a": {"b": {"c": "e"}}}, {"a": {"b": {"c": "e"}}}) ]) def test_merge_jsonlike_merges_jsonlike_objects_correctly(source_object, destination_object, expected_result): merge_jsonlike(source_object, destination_object)