CSHARP-5453: Add builder for CSFLE schemas (#1631)

Author: papafe

src/MongoDB.Bson/ObjectModel/BsonTypeExtensions.cs

@@ -0,0 +1,57 @@
+/* Copyright 2010-present MongoDB Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+using System;
+
+namespace MongoDB.Bson
+{
+    /// <summary>
+    /// A static class containing extension methods for <see cref="BsonType"/>.
+    /// </summary>
+    public static class BsonTypeExtensions
+    {
+        /// <summary>
+        /// Maps a <see cref="BsonType"/> to its corresponding server string representation.
+        /// </summary>
+        /// <param name="type">The input type to map.</param>
+        public static string ToServerString(this BsonType type)
+        {
+            return type switch
+            {
+                BsonType.Array => "array",
+                BsonType.Binary => "binData",
+                BsonType.Boolean => "bool",
+                BsonType.DateTime => "date",
+                BsonType.Decimal128 => "decimal",
+                BsonType.Document => "object",
+                BsonType.Double => "double",
+                BsonType.Int32 => "int",
+                BsonType.Int64 => "long",
+                BsonType.JavaScript => "javascript",
+                BsonType.JavaScriptWithScope => "javascriptWithScope",
+                BsonType.MaxKey => "maxKey",
+                BsonType.MinKey => "minKey",
+                BsonType.Null => "null",
+                BsonType.ObjectId => "objectId",
+                BsonType.RegularExpression => "regex",
+                BsonType.String => "string",
+                BsonType.Symbol => "symbol",
+                BsonType.Timestamp => "timestamp",
+                BsonType.Undefined => "undefined",
+                _ => throw new ArgumentException($"Unexpected BSON type: {type}.", nameof(type))
+            };
+        }
+    }
+}