Normalize breakingSpaces like regular whiteSpaces

[maximedezette]

Check List:

• Fixes isEqualToNormalizingWhitespace doesn't normalise non breaking space characters #3113
• Unit tests : YES
• Javadoc with a code example (on API only) : YES
• PR meets the contributing guidelines

Following the contributing guidelines will make it easier for us to review and accept your PR.

Note

I think that the breaking-space management could be improved by using a public constant so that we don't have to update all the tests if some of the breaking space codes change over time. It would look like this:

    Stream<Arguments> breakingSpaces = Arrays.stream(Strings.BREAKING_SPACES)
      .map(breakingSpace -> Arguments.of("my" + breakingSpace + "foo bar", "my foo bar"));
    Stream<Arguments> regularSpaces = Stream.of(Arguments.of("my   foo bar", "my foo bar"),
      Arguments.of("  my foo bar  ", "my foo bar"),
      Arguments.of(" my\tfoo bar ", " my foo bar"),
      Arguments.of(" my foo    bar ", "my foo bar"),
      Arguments.of(" my foo    bar ", "  my foo bar   "),
      Arguments.of("       ", " "),
      Arguments.of(" my\tfoo bar ", new String(arrayOf(' ', 'm', 'y', ' ', 'f', 'o', 'o', ' ', 'b', 'a', 'r'))),
      Arguments.of(" my\tfoo bar ", " my\tfoo bar "),   // same
      Arguments.of(null, null),   // null
      Arguments.of(" \t \t", " "),
      Arguments.of(" abc", "abc ")
    );
    return Stream.concat(regularSpaces, breakingSpaces);

Instead of having to update all the tests:

What do you think ?

[scordio]

Thank you, @maximedezette! I've put some comments.

Could you please also enhance the Javadoc as mentioned in #3113 (comment)?

Lastly, the build is failing due to formatting issues. You can run ./mvnw spotless:apply to make sure that all changes adhere to the expected code style.

[scordio]

@maximedezette This PR has now several merge conflicts but you don't need to worry about them: I've taken the opportunity to do some refactoring in the surrounding area to better evaluate if we should also change other assertions relying on whitespaces.

Once I'm done with the refactoring, I'll cherry-pick your changes maintaining you as the author.

[maximedezette]

@scordio I have missed your comment mentioning the cherry-pick and I've done the rebase 😅

I have thrown away a bit of code about the refactoring of non-breaking spaces tests but I'll do an other PR if I feel that it could improve the tests after your refactoring 👍

[scordio]

@maximedezette sorry for the slow feedback!

I just refreshed your branch and made some cosmetic changes.

Also, I noticed that this change will also affect isNotEqualToNormalizingWhitespace and isEqualToNormalizingPunctuationAndWhitespace. I already aligned the Javadoc but we should also have tests for those assertions.

Would you like to add the missing tests? No problem if you don't have time, I can take care of them next week.

[maximedezette]

@scordio I don't have time at the moment but if it can wait a few days, I should be able to add those tests this week 👍

[scordio]

Thanks for your first contribution, @maximedezette!