src/NLog/LayoutRenderers/Wrappers/WhenEmptyLayoutRendererWrapper.cs (1)

88-104: Logic is correct and well-structured.

The method correctly handles all combinations:

• Non-empty inner fixed text → always return inner (never empty)
• Empty inner fixed text with fixed whenEmpty → return whenEmpty constant
• Empty inner fixed text with dynamic whenEmpty → render whenEmpty at runtime
• Other cases → return null to fall back to general rendering

The defensive null coalescing operators on lines 92 and 96 are good practice.

📝 Consider adding XML documentation

Adding XML comments would clarify the optimization strategy:

+/// <summary>
+/// Resolves the optimal string renderer when the inner layout is fixed text.
+/// Returns a pre-determined renderer if possible, or null to fall back to general rendering.
+/// </summary>
 private static Func<LogEventInfo, string>? ResolveFixedWhenEmpty(SimpleLayout innerLayout, SimpleLayout whenEmptyLayout)

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Review profile: CHILL

Plan: Pro