[Core] Support diff toolwindow in IntelliJ IDEA

[avokin2]

For the toolwindow are required the "expected" and "actual" attributes in the test-failed-output message.

This fixes issue: #2607

🤔 What's changed?

⚡️ What's your motivation?

🏷️ What kind of change is this?

• 🏦 Refactoring/debt/DX (improvement to code design, tooling, documentation etc. without changing behaviour)
• 🐛 Bug fix (non-breaking change which fixes a defect)
• ⚡ New feature (non-breaking change which adds new behaviour)
• 💥 Breaking change (incompatible changes to the API)

♻️ Anything particular you want feedback on?

📋 Checklist:

• I agree to respect and uphold the Cucumber Community Code of Conduct
• I've changed the behaviour of the code
  • I have added/updated tests to cover my changes.
• My change requires a change to the documentation.
  • I have updated the documentation accordingly.
• Users should know about my change
  • I have added an entry to the "Unreleased" section of the CHANGELOG, linking to this pull request.

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[mpkorstanje]

Looks good on the main points. However I do feel some important details are missing and the test coverage is a bit spotty.

Please also update the CHANGELOG.md and run mvn spotless:apply to fix the formatting.

[codecov]

Codecov Report

Merging #2608 (3e0a702) into main (fe56287) will increase coverage by 0.14%.
The diff coverage is 90.90%.

❗ Current head 3e0a702 differs from pull request most recent head 577d9c8. Consider uploading reports for the commit 577d9c8 to get more accurate results

@@             Coverage Diff              @@
##               main    #2608      +/-   ##
============================================
+ Coverage     84.72%   84.87%   +0.14%     
- Complexity     2696     2699       +3     
============================================
  Files           320      320              
  Lines          9512     9544      +32     
  Branches        908      913       +5     
============================================
+ Hits           8059     8100      +41     
+ Misses         1123     1111      -12     
- Partials        330      333       +3     

Impacted Files	Coverage Δ
...n/java/io/cucumber/core/plugin/TeamCityPlugin.java	88.26% <90.90%> (+0.38%)	⬆️
...ucumber/core/runner/PickleStepDefinitionMatch.java	96.05% <0.00%> (+3.94%)	⬆️
...ava/io/cucumber/core/runner/StackManipulation.java	65.51% <0.00%> (+31.03%)	⬆️

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[mpkorstanje]

@avokin I've pushed fixes for the suggestions I've made above. That was a bit quicker. Also added support for AssertJ, Testng and JUnit4. That should cover the most common frameworks I think.

[avokin2]

Thank you!

Should I fix anything else?

[mpkorstanje]

No, I think this is okay for now. Release will happen soonish.

[aslakhellesoy]

Hi @avokin2,

Thanks for your making your first contribution to Cucumber, and welcome to the Cucumber committers team! You can now push directly to this repo and all other repos under the cucumber organization! 🍾

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