Encode/Decode Extension Addition (QuantConnect#5708)

* Implement Encode/Decode Base 64

* Add unit test

Common/Extensions.cs

@@ -728,6 +728,38 @@ public static ulong DecodeBase36(this string symbol)
             return result;
         }
 
+        /// <summary>
+        /// Convert a string to Base64 Encoding
+        /// </summary>
+        /// <param name="text">Text to encode</param>
+        /// <returns>Encoded result</returns>
+        public static string EncodeBase64(this string text)
+        {
+            if (string.IsNullOrEmpty(text))
+            {
+                return text;
+            }
+
+            byte[] textBytes = Encoding.UTF8.GetBytes(text);
+            return Convert.ToBase64String(textBytes);
+        }
+
+        /// <summary>
+        /// Decode a Base64 Encoded string
+        /// </summary>
+        /// <param name="base64EncodedText">Text to decode</param>
+        /// <returns>Decoded result</returns>
+        public static string DecodeBase64(this string base64EncodedText)
+        {
+            if (string.IsNullOrEmpty(base64EncodedText))
+            {
+                return base64EncodedText;
+            }
+
+            byte[] base64EncodedBytes = Convert.FromBase64String(base64EncodedText);
+            return Encoding.UTF8.GetString(base64EncodedBytes);
+        }
+
         /// <summary>
         /// Lazy string to upper implementation.
         /// Will first verify the string is not already upper and avoid

Tests/Common/StringExtensionsTests.cs

@@ -1,4 +1,4 @@
-/*
+/*
  * QUANTCONNECT.COM - Democratizing Finance, Empowering Individuals.
  * Lean Algorithmic Trading Engine v2.0. Copyright 2014 QuantConnect Corporation.
  *
@@ -227,5 +227,15 @@ public void SafeSubstring_ReturnsSubstring_WhenSubstringThrowException(string so
             }
             Assert.AreEqual(expected, sourceString.SafeSubstring(startIndex, length));
         }
+
+        [TestCase("test input")]
+        [TestCase("[ asdd[ \" 12344 :::}")]
+        public void EncodeDecode64String(string input)
+        {
+            var encoded = input.EncodeBase64();
+            var decoded = encoded.DecodeBase64();
+
+            Assert.AreEqual(input, decoded);
+        }
     }
-}
+}