New rule S2970: Assertions should be complete

[gregory-paidis-sonarsource]

S2970
RSpec change: SonarSource/rspec#1518

Related rule S2699 implemented in TestMethodShouldContainAssertion

Methods/Props without "continuation" that should be detected:

• MSTest: Update: Assert.That is a property and can not be misused.
  • https://learn.microsoft.com/dotnet/api/microsoft.visualstudio.testtools.unittesting.assert.that Assert.That
  • https://learn.microsoft.com/dotnet/api/microsoft.visualstudio.testtools.unittesting.stringassert.that StringAssert.That
  • https://learn.microsoft.com/dotnet/api/microsoft.visualstudio.testtools.unittesting.collectionassert.that CollectionAssert.That
• Fluent Assertions: https://fluentassertions.com/introduction Should()
• NFluent: https://www.n-fluent.net Check.That()
• NSubstitute: https://nsubstitute.github.io/help/received-calls Received() and related like DidNotReceiveWithAnyArgs()

Unaffected libraries:

• NUnit
• xUnit
• Shoudly

Existing rules in the testing libs:

• NFluent: https://github.com/tpierrain/NFluent/blob/9fa14534df80d129149f32204848b12a57aac98a/code/src/Analyzer/NFluent.Analyzer/NFluent.Analyzer/NFluentAnalyzer.cs#L96-L104
• NSubstitute: https://github.com/nsubstitute/NSubstitute.Analyzers/blob/dev/documentation/rules/NS5000.md

[gregory-paidis-sonarsource]

This rule could be implemented as an additional diagnostic inside of S2699.
This will improve the precision of the rule's raised diagnostic, while also being faster than implementing similar logic twice, at least up until a point.

[martin-strecker-sonarsource]

MSTest was removed because Assert.That is a property and can not be used as a standalone statement.