NoInterpolationInSerilogAnalyzer.cs

    /// <summary>
    /// Serilog won't be able to pull structured props out of a C# interpolated string.
    /// See https://nblumhardt.com/2015/01/c-6-string-interpolation-and-serilog/
    /// </summary>
    [DiagnosticAnalyzer(LanguageNames.CSharp)]
    public class NoInterpolationInSerilogAnalyzer : DiagnosticAnalyzer
    {
        const string Category = "Logging";
        const string Title = "String interpolation breaks Serilog structuring";
        const string MessageFormat = "String interpolation breaks Serilog structuring";
        const string Description = "String interpolation breaks Serilog structuring. See https://nblumhardt.com/2015/01/c-6-string-interpolation-and-serilog/";

        static readonly DiagnosticDescriptor Rule = new DiagnosticDescriptor("REPLACEME", Title, MessageFormat, Category, DiagnosticSeverity.Error, true, Description);

        public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => ImmutableArray.Create(Rule);

        public override void Initialize(AnalysisContext context)
        {
            context.RegisterSyntaxNodeAction(analysisContext =>
            {
                var n = (InvocationExpressionSyntax)analysisContext.Node;
                var firstInterpolatedString = n.ArgumentList.Arguments
                    .Select(x => x.Expression)
                    .OfType<InterpolatedStringExpressionSyntax>()
                    .FirstOrDefault();

                if (firstInterpolatedString == null)
                {
                    return;
                }

                if (n.Expression is MemberAccessExpressionSyntax ma)
                {
                    //are we calling the method on something that belongs to Serilog?
                    var typeInfo = analysisContext.SemanticModel.GetTypeInfo(ma.Expression);
                    if (typeInfo.Type.ContainingNamespace.Name == "Serilog")
                    {
                        analysisContext.ReportDiagnostic(Diagnostic.Create(Rule, firstInterpolatedString.GetLocation()));
                    }
                }


            }, SyntaxKind.InvocationExpression);
        }
    }