Refactor AbpAppPath method to include null checks and streamline script generation

framework/src/Volo.Abp.Swashbuckle/Microsoft/Extensions/DependencyInjection/AbpSwaggerUIOptionsExtensions.cs

@@ -1,7 +1,9 @@
 using System;
 using System.Text;
 using System.Text.Json;
+using JetBrains.Annotations;
 using Swashbuckle.AspNetCore.SwaggerUI;
+using Volo.Abp;
 
 namespace Microsoft.Extensions.DependencyInjection;
 
@@ -12,19 +14,34 @@ public static class AbpSwaggerUIOptionsExtensions
     /// </summary>
     /// <param name="options">The Swagger UI options.</param>
     /// <param name="appPath">The application base path.</param>
-    public static void AbpAppPath(this SwaggerUIOptions options, string appPath)
+    public static void AbpAppPath([NotNull] this SwaggerUIOptions options, [NotNull] string appPath)
     {
+        Check.NotNull(options, nameof(options));
+        Check.NotNull(appPath, nameof(appPath));
+
         var normalizedAppPath = NormalizeAppPath(appPath);
-        var builder = new StringBuilder(options.HeadContent ?? string.Empty);
-        builder.AppendLine("<script>");
-        builder.AppendLine("    var abp = abp || {};");
-        builder.AppendLine($"    abp.appPath = {JsonSerializer.Serialize(normalizedAppPath)};");
-        builder.AppendLine("</script>");
-        options.HeadContent = builder.ToString();
+        options.HeadContent = BuildAppPathScript(normalizedAppPath, options.HeadContent ?? string.Empty);
     }
 
     private static string NormalizeAppPath(string appPath)
     {
-        return string.IsNullOrWhiteSpace(appPath) ? "/" : appPath.Trim().EnsureStartsWith('/').EnsureEndsWith('/');
+        return string.IsNullOrWhiteSpace(appPath)
+            ? "/"
+            : appPath.Trim().EnsureStartsWith('/').EnsureEndsWith('/');
+    }
+
+    private static string BuildAppPathScript(string normalizedAppPath, string headContent)
+    {
+        var builder = new StringBuilder(headContent);
+        if (builder.Length > 0)
+        {
+            builder.AppendLine();
+        }
+
+        builder.AppendLine("<script>");
+        builder.AppendLine("    var abp = abp || {};");
+        builder.AppendLine($"    abp.appPath = {JsonSerializer.Serialize(normalizedAppPath)};");
+        builder.AppendLine("</script>");
+        return builder.ToString();
     }
 }