Refactoring: Extract StringExtensions

BTCPayServer.Abstractions/Extensions/StringExtensions.cs

@@ -0,0 +1,45 @@
+using System;
+using System.IO;
+using System.Linq;
+
+namespace BTCPayServer.Abstractions.Extensions;
+
+public static class StringExtensions
+{
+
+    public static bool IsValidFileName(this string fileName)
+    {
+        return !fileName.ToCharArray().Any(c => Path.GetInvalidFileNameChars().Contains(c)
+                                                || c == Path.AltDirectorySeparatorChar
+                                                || c == Path.DirectorySeparatorChar
+                                                || c == Path.PathSeparator
+                                                || c == '\\');
+    }
+
+    public static string Truncate(this string value, int maxLength)
+    {
+        if (string.IsNullOrEmpty(value))
+            return value;
+        return value.Length <= maxLength ? value : value.Substring(0, maxLength);
+    }
+
+    public static string WithTrailingSlash(this string str)
+    {
+        if (str.EndsWith("/", StringComparison.InvariantCulture))
+            return str;
+        return str + "/";
+    }
+    public static string WithStartingSlash(this string str)
+    {
+        if (str.StartsWith("/", StringComparison.InvariantCulture))
+            return str;
+        return $"/{str}";
+    }
+    public static string WithoutEndingSlash(this string str)
+    {
+        if (str.EndsWith("/", StringComparison.InvariantCulture))
+            return str.Substring(0, str.Length - 1);
+        return str;
+    }
+    
+}