fix(central-ui): resolve CentralUI-015..019 — pager windowing, logout CSRF, narrowed catch blocks, coverage; CentralUI-015 re-triaged Won't Fix

tests/ScadaLink.CentralUI.Tests/Shared/MonacoEditorLoggingTests.cs

@@ -0,0 +1,77 @@
+using Bunit;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
+using Microsoft.JSInterop;
+using ScadaLink.CentralUI.Components.Shared;
+
+namespace ScadaLink.CentralUI.Tests.Shared;
+
+/// <summary>
+/// Regression tests for CentralUI-018. <c>MonacoEditor</c> wrapped every JS
+/// interop call in a bare <c>try { ... } catch { }</c> with no logging — a
+/// genuine Monaco init failure became invisible. The fix narrows the catch to
+/// the expected prerender / disconnect cases and logs any real
+/// <see cref="JSException"/> via <c>ILogger</c>.
+/// </summary>
+public class MonacoEditorLoggingTests : BunitContext
+{
+    /// <summary>Captures log entries so the test can assert on them.</summary>
+    private sealed class CapturingLoggerProvider : ILoggerProvider
+    {
+        public List<(LogLevel Level, string Message, Exception? Exception)> Entries { get; } = new();
+
+        public ILogger CreateLogger(string categoryName) => new CapturingLogger(Entries);
+        public void Dispose() { }
+
+        private sealed class CapturingLogger : ILogger
+        {
+            private readonly List<(LogLevel, string, Exception?)> _entries;
+            public CapturingLogger(List<(LogLevel, string, Exception?)> entries) => _entries = entries;
+
+            public IDisposable? BeginScope<TState>(TState state) where TState : notnull => null;
+            public bool IsEnabled(LogLevel logLevel) => true;
+
+            public void Log<TState>(LogLevel logLevel, EventId eventId, TState state,
+                Exception? exception, Func<TState, Exception?, string> formatter)
+                => _entries.Add((logLevel, formatter(state, exception), exception));
+        }
+    }
+
+    [Fact]
+    public void CreateEditor_GenuineJsException_IsLogged_NotSwallowed()
+    {
+        var provider = new CapturingLoggerProvider();
+        Services.AddLogging(b => b.AddProvider(provider));
+
+        // createEditor is an InvokeVoidAsync call — configure it to throw a
+        // genuine JSException so we exercise the real-failure path.
+        JSInterop.Mode = JSRuntimeMode.Strict;
+        JSInterop.SetupVoid("MonacoBlazor.createEditor", _ => true)
+            .SetException(new JSException("Monaco failed to load"));
+
+        // Pre-fix: the bare catch {} swallowed this with no trace. Post-fix:
+        // the component renders fine but the failure is logged.
+        var cut = Render<MonacoEditor>(p => p.Add(c => c.ShowToolbar, false));
+
+        var errors = provider.Entries.Where(e => e.Level == LogLevel.Error).ToList();
+        Assert.NotEmpty(errors);
+        Assert.Contains(errors, e => e.Exception is JSException);
+    }
+
+    [Fact]
+    public void CreateEditor_Prerender_DoesNotLog()
+    {
+        // When JS interop is unavailable (prerender), createEditor throws
+        // InvalidOperationException — that is expected and must NOT be logged.
+        var provider = new CapturingLoggerProvider();
+        Services.AddLogging(b => b.AddProvider(provider));
+
+        JSInterop.Mode = JSRuntimeMode.Strict;
+        JSInterop.SetupVoid("MonacoBlazor.createEditor", _ => true)
+            .SetException(new InvalidOperationException("JS interop not available during prerender"));
+
+        var cut = Render<MonacoEditor>(p => p.Add(c => c.ShowToolbar, false));
+
+        Assert.DoesNotContain(provider.Entries, e => e.Level >= LogLevel.Warning);
+    }
+}