Print collections of long strings over multiple lines

Discussed in https://github.com/fluentassertions/fluentassertions/discussions/1722

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^{Originally posted by rcdailey October 27, 2021} When I have a BeEquivalentTo() comparison between two lists of strings, the output looks like this:

Expected DynamicMenuTestHelpers.FixupCaptions(menu.ItemLinks) to be a collection with 4 item(s), but {"Generate Report (DR Objects)", "Generate Report (Non-DR Objects)"}"
"contains 2 item(s) less than"
"{"Schedule Disaster Recovery Backups...", "Run Backup Now", "Generate Report (DR Objects)", "Generate Report (Non-DR Objects)"}.

I personally find this difficult to read, mainly because everything is on one line. Is there a way to make this print out “prettier”? Something as simple as one string per line I think might make this more legible.</div>

[rcdailey]

Along the lines of making this more “Readable”, I thought of another idea:

Instead of saying:

Expected a list of 4 items:
  - "Apple"
  - "Banana"
  - "Cantaloupe"
  - "Durian"

But got 2 instead:
  - "Apple"
  - "Durian"

Instead, just show what is missing:

Expected a list of 4 items, but the following 2 are missing:
  - "Banana"
  - "Cantaloupe"

This is shorter, easier to read, and a little less confusing. I personally am only interested in what is missing. I usually look at the unit test code anyway to see what was there. Maybe there’s a different set of valid use cases for both, so I’d also be happy with the “delta” version of this (the bottom example) being an opt-in feature.

So really I’d boil down this issue into two main parts:

• Make what is there more readable by breaking up lists of items into multiple lines
• Reduce the “boilerplate” text in the assertion failure to focus more on what is missing, rather than what is present, as I believe that is more helpful to resolving test failures.

Thank you for being so open minded about my suggestions! Love the library!!

[rcdailey]

@Constante-ou-Mort The FluentAssertions developers are likely not paid to do work here, nor do they work for you. Respectfully, if you want to see change, it would be far more productive to fork the repository and contribute code. If you aren’t willing to do that, the best you can do is thumbs up the issue and move on. Your comments are a distraction to the developers and to others subscribed to this issue to be notified of meaningful updates.

I apologize that my tone seems aggressive or rude; I only intend to be frank. I hope you understand. It’s hard for me to wait too, but that’s open source.

To the maintainers: My feelings wouldn’t be hurt if you decided to lock conversation on this issue to maintainers only.