Setter for TextArea load_text

[davetapley]

As discussed #3525 (reply in thread)

Please review the following checklist.

• Docstrings on all new or modified functions / classes
• Updated documentation
• Updated CHANGELOG.md (where appropriate)

[davetapley]

Thoughts on tests / doc changes? 🤔

[TomJGooding]

I'm not a maintainer of Textual, but your code is missing type annotations and I've suggested tweaks to the docstring.

Do you think you could also add a simple test?

[davetapley]

Thanks @TomJGooding, I wasn't sure about the argument doc string for a setter, but I guess there's no harm.

And r.e. tests it seems needlessly duplicitous when we already have load_text covered.
I suppose I could test that the setter calls that with a mock, but that's not really testing anything 🤪

[TomJGooding]

Sorry you might be right with this only being a setter. I think I was just on auto-pilot (and my change upset black).

I will mind my own business and leave this for the maintainers!

[darrenburns]

A simple test is still valuable as a guard against future regressions - it's a simple setter for now but could be modified in the future, so we want to capture it's expected behaviour. Just something like this would suffice:

new_text = "hello\nworld\n"
text_area.text = new_text
assert text_area.text == new_text

[darrenburns]

I wrote this test here for it, but I think your fork is locked as I can't push to this PR:

async def test_text_setter():
    app = TextAreaApp()
    async with app.run_test():
        text_area = app.query_one(TextArea)
        new_text = "hello\nworld\n"
        text_area.text = new_text
        assert text_area.text == new_text

Also, if you could add a CHANGELOG.md entry too when you get a moment, that'd be great.

[darrenburns]

Looks good, thanks!