MultiDiagnosticSymbolAnalyzer¶

MultiDiagnosticSymbolAnalyzer<TSymbol, TItem> is for analyzers that report zero or more diagnostics per symbol — one for each problematic item found.

Quick Start¶

[Reports("DSRK001", "Pipeline model property uses ImmutableArray<T>",
    Message = "Property '{0}' on '{1}' uses ImmutableArray<T> — use EquatableArray<T>",
    Category = "PipelineModel")]
public sealed class ImmutableArrayAnalyzer : MultiDiagnosticTypeAnalyzer<ValidSymbol<IPropertySymbol>>
{
    protected override IEnumerable<ValidSymbol<IPropertySymbol>> GetDiagnosticItems(
        ValidSymbol<INamedTypeSymbol> type)
    {
        if (type.LacksAttribute<PipelineModelAttribute>())
            yield break;

        foreach (var prop in type.QueryProperties().ThatAreInstance()
                     .Where(x => x.Type.IsImmutableArrayType()).GetAll())
            yield return prop;
    }

    protected override object[] GetMessageArgs(
        ValidSymbol<INamedTypeSymbol> symbol, ValidSymbol<IPropertySymbol> item)
        => [item.Name, symbol.Name];

    protected override Location GetLocation(
        ValidSymbol<INamedTypeSymbol> symbol, ValidSymbol<IPropertySymbol> item)
        => item.Location;
}

How It Works¶

Declare the diagnostic via [Reports] — one rule shared by all items
For each symbol, GetDiagnosticItems returns items that should produce diagnostics
Each item becomes one Diagnostic.Create call with custom location and message args

Specialized Aliases¶

Alias	Equivalent To
`MultiDiagnosticTypeAnalyzer<TItem>`	`MultiDiagnosticSymbolAnalyzer<INamedTypeSymbol, TItem>`
`MultiDiagnosticMethodAnalyzer<TItem>`	`MultiDiagnosticSymbolAnalyzer<IMethodSymbol, TItem>`
`MultiDiagnosticPropertyAnalyzer<TItem>`	`MultiDiagnosticSymbolAnalyzer<IPropertySymbol, TItem>`

Abstract & Virtual Members¶

Member	Kind	Default	Description
`GetDiagnosticItems(symbol)`	abstract	—	Return items that should each produce a diagnostic
`GetMessageArgs(symbol, item)`	virtual	`[symbol.Name]`	Message format arguments
`GetLocation(symbol, item)`	virtual	`symbol.Location`	Diagnostic location
`GetProperties(symbol, item)`	virtual	`null`	Properties forwarded to code fixes

Comparison with SymbolAnalyzer¶

	`SymbolAnalyzer<T>`	`MultiDiagnosticSymbolAnalyzer<T, I>`
Diagnostics per symbol	One	Zero or more
Override	`ShouldReport(symbol) → bool`	`GetDiagnosticItems(symbol) → IEnumerable<TItem>`
Location	Type declaration	Custom via `GetLocation()`
Message args	Type name only	Custom via `GetMessageArgs()`
Properties	None	Custom via `GetProperties()`