Unit tests for widgets

[lapp0]

Obvious unworkability not caught by tests #60 (comment)

We need to implement tests for the behavior for all widgets eventually. They can be tackled one at a time, pull requests needn't cover all of these.

These unit tests should mock out any calls to state_model or api. They also should only create an instance of the widget being tested, not the entirety of Nix-Gui.

Tests

Utilities:

https://github.com/pytest-dev/pytest-mock

https://docs.python.org/3/library/unittest.mock.html

field_widgets.py

• For each non-Redirect widget create a single test function which does the following

1. call __init__
2. ensure current_value() is a sane default and works (e.g. BooleanField should be False)
3. use pytest.mark.parameterize to call load_value()
4. ensure current_value() is the passed value

For Null assert it's current_value is None,

UndefinedField -> Undefined,

NotImplementedField -> assert raises an exception

navbar.py

• assert up_fn called when up is clicked (with mocked fn and check call)
• assert set_lookup_key_fn(None) called when back is clicked
• pass mocked set_lookup_key_fn
  • use qt to enter text into path_textbox and assert set_lookup_key_fn called with search key
  • use qt to enter text into search_textbox and assert set_lookup_key_fn called with search:text

navlist.py

• ensure clicking an item in SearchResultListDisplay results in a call to self.set_option_path_callback

• ensure clicking an item in StaticAttrsOf results in a call to self.set_option_path_callback

• TODO: Need to complete Complete Implementation of ListOf #30 and DynamicAttrsOf Improvements #72 before writing tests for DynamicListOf and DynamicAttrsOf

option_display.py

• load Undefined, ensure everything is hidden, undefined toggle is off
• load defined value, ensure everything is shown
• load defined value that can be an int, bool, or str. Ensure clicking each type changes the active widget in self.entry_stack, also ensure no Updates are created

Integration Tests (out of scope of the issue?)

search

• load a search result

navlist.py

• add, delete, and rename a DynamicAttrsOf item
• add, delete, and reorder a DynamicListOf item (make it more rigid so error: file 'nixos/modules' was not found in the Nix search path #224 (comment) doesn't happen again)