Eliminate PortTracker stub backlog by implementing Raft/file-store/stream/server/client/OCSP stubs and adding coverage. This makes all tracked stub features/tests executable and verified in the current porting phase.

dotnet/src/ZB.MOM.NatsNet.Server/JetStream/JetStreamErrors.cs

@@ -45,6 +45,8 @@ public sealed class JsApiError
 /// </summary>
 public static class JsApiErrors
 {
+    public delegate object? ErrorOption();
+
     // ---- Account ----
     public static readonly JsApiError AccountResourcesExceeded                = new() { Code = 400, ErrCode = 10002, Description = "resource limits exceeded for account" };
 
@@ -315,9 +317,104 @@ public static class JsApiErrors
     /// </summary>
     public static bool IsNatsError(JsApiError? err, params ushort[] errCodes)
     {
-        if (err is null) return false;
-        foreach (var code in errCodes)
-            if (err.ErrCode == code) return true;
+        return IsNatsErr(err, errCodes);
+    }
+
+    /// <summary>
+    /// Returns true if <paramref name="err"/> is a <see cref="JsApiError"/> and matches one of the supplied IDs.
+    /// Unknown IDs are ignored, matching Go's map-based lookup behavior.
+    /// </summary>
+    public static bool IsNatsErr(object? err, params ushort[] ids)
+    {
+        if (err is not JsApiError ce)
+            return false;
+
+        foreach (var id in ids)
+        {
+            var ae = ForErrCode(id);
+            if (ae != null && ce.ErrCode == ae.ErrCode)
+                return true;
+        }
+
         return false;
     }
+
+    /// <summary>
+    /// Formats an API error string exactly as Go <c>ApiError.Error()</c>.
+    /// </summary>
+    public static string Error(JsApiError? err) => err?.ToString() ?? string.Empty;
+
+    /// <summary>
+    /// Creates an option that causes constructor helpers to return the provided
+    /// <see cref="JsApiError"/> when present.
+    /// Mirrors Go <c>Unless</c>.
+    /// </summary>
+    public static ErrorOption Unless(object? err) => () => err;
+
+    /// <summary>
+    /// Mirrors Go <c>NewJSRestoreSubscribeFailedError</c>.
+    /// </summary>
+    public static JsApiError NewJSRestoreSubscribeFailedError(Exception err, string subject, params ErrorOption[] opts)
+    {
+        var overridden = ParseUnless(opts);
+        if (overridden != null)
+            return overridden;
+
+        return NewWithTags(
+            RestoreSubscribeFailed,
+            ("{err}", err.Message),
+            ("{subject}", subject));
+    }
+
+    /// <summary>
+    /// Mirrors Go <c>NewJSStreamRestoreError</c>.
+    /// </summary>
+    public static JsApiError NewJSStreamRestoreError(Exception err, params ErrorOption[] opts)
+    {
+        var overridden = ParseUnless(opts);
+        if (overridden != null)
+            return overridden;
+
+        return NewWithTags(StreamRestore, ("{err}", err.Message));
+    }
+
+    /// <summary>
+    /// Mirrors Go <c>NewJSPeerRemapError</c>.
+    /// </summary>
+    public static JsApiError NewJSPeerRemapError(params ErrorOption[] opts)
+    {
+        var overridden = ParseUnless(opts);
+        return overridden ?? Clone(PeerRemap);
+    }
+
+    private static JsApiError? ParseUnless(ReadOnlySpan<ErrorOption> opts)
+    {
+        foreach (var opt in opts)
+        {
+            var value = opt();
+            if (value is JsApiError apiErr)
+                return Clone(apiErr);
+        }
+
+        return null;
+    }
+
+    private static JsApiError Clone(JsApiError source) => new()
+    {
+        Code = source.Code,
+        ErrCode = source.ErrCode,
+        Description = source.Description,
+    };
+
+    private static JsApiError NewWithTags(JsApiError source, params (string key, string value)[] replacements)
+    {
+        var clone = Clone(source);
+        var description = clone.Description ?? string.Empty;
+
+        foreach (var (key, value) in replacements)
+            description = description.Replace(key, value, StringComparison.Ordinal);
+
+        clone.Description = description;
+        return clone;
+    }
 }