spectre.console/src/Spectre.Console.Analyzer/Analyzers/UseSpectreInsteadOfSystemConsoleAnalyzer.cs

using System.Collections.Immutable;
using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.CSharp;
using Microsoft.CodeAnalysis.Diagnostics;
using Microsoft.CodeAnalysis.Operations;

namespace Spectre.Console.Analyzer;

/// <summary>
/// Analyzer to enforce the use of AnsiConsole over System.Console for known methods.
/// </summary>
[DiagnosticAnalyzer(LanguageNames.CSharp)]
public class UseSpectreInsteadOfSystemConsoleAnalyzer : SpectreAnalyzer
{
    private static readonly DiagnosticDescriptor _diagnosticDescriptor =
        Descriptors.S1000_UseAnsiConsoleOverSystemConsole;

    private static readonly string[] _methods = { "WriteLine", "Write" };

    /// <inheritdoc />
    public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics =>
        ImmutableArray.Create(_diagnosticDescriptor);

    /// <inheritdoc />
    protected override void AnalyzeCompilation(CompilationStartAnalysisContext compilationStartContext)
    {
        compilationStartContext.RegisterOperationAction(
            context =>
            {
                // if this operation isn't an invocation against one of the System.Console methods
                // defined in _methods then we can safely stop analyzing and return;
                var invocationOperation = (IInvocationOperation)context.Operation;

                var methodName = System.Array.Find(_methods, i => i.Equals(invocationOperation.TargetMethod.Name));
                if (methodName == null)
                {
                    return;
                }

                var systemConsoleType = context.Compilation.GetTypeByMetadataName("System.Console");

                if (!Equals(invocationOperation.TargetMethod.ContainingType, systemConsoleType))
                {
                    return;
                }

                var methodSymbol = invocationOperation.TargetMethod;

                var displayString = SymbolDisplay.ToDisplayString(
                    methodSymbol,
                    SymbolDisplayFormat.CSharpShortErrorMessageFormat
                        .WithParameterOptions(SymbolDisplayParameterOptions.None)
                        .WithGenericsOptions(SymbolDisplayGenericsOptions.None));

                context.ReportDiagnostic(
                    Diagnostic.Create(
                        _diagnosticDescriptor,
                        invocationOperation.Syntax.GetLocation(),
                        displayString));
            }, OperationKind.Invocation);
    }
}