New Rule S2094: Classes should not be empty

[zsolt-kolbay-sonarsource]

Fixes #6704
Related RSPEC PR

[antonioaversa]

@zsolt-kolbay-sonarsource : you may want to have a look at the failing GitHub actions checks.

I think I can start the review anyway.

[antonioaversa]

Mostly tests to add and code conventions remarks.

Source generation and abstract classes without abstract methods may require further analysis.

Another general remarks is whether this rule should also consider struct and record struct. While the rule explicitly mention classes, other languages such as Java don't have the struct construct, while others, such as C++, are excluded from the rule for reasons explained in the comments.

[antonioaversa]

LGTM, just a couple of minor remarks + the "source generators" topic, on which I let @andrei-epure-sonarsource answer.

[andrei-epure-sonarsource]

interim comments on java IT

[andrei-epure-sonarsource]

interim comments

[andrei-epure-sonarsource]

interim

[andrei-epure-sonarsource]

The build is failing, you probably need to update an UT.

All good, only one small comment left #6754 (comment)

Request changes as the PR cannot be merged as is.

[andrei-epure-sonarsource]

LGTM, but please remove the redundant safety check - I've looked into the types and it's not necessary (see #6754 (comment) )

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

No Coverage information
No Duplication information

[sonarcloud]

SonarCloud Quality Gate failed.   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
1 Code Smell

92.5% Coverage
0.0% Duplication

[pavel-mikula-sonarsource]

@zsolt-kolbay-sonarsource I was looking at coverage and noticed this new line.

According to coding style, the expression body should have been on a new line. Please fix it in any next random PR. Same above and on VB.

protected override string DeclarationTypeKeyword(SyntaxNode node) => 
    ((TypeDeclarationSyntax)node).Keyword.ValueText;