add NRT test (#23)

Check NRT are working correctly.
:warning: if value is missing, NRT can't be considered null as of now.

Author: pchalamet

Diff for: README.md

@@ -4,7 +4,7 @@
 
 ## Goals of this project
 
-  * Provide an idiomatic F# API for interacting with MongoDB.
+  * Provide support for F# types for interacting with MongoDB.
   * Have an implementation that is fully testable without connecting to a server.
   * Isomorphic bson serialization for C# and F#.
 
@@ -84,6 +84,13 @@ If you want to auto-generate `ObjectId` (as the Id of the collection), add `[<CL
 The case of the discriminated union is stored in `_t` key.
 Each value of the DU is serialized as an `object` using its corresponding value name.
 
+## Nullable Reference Type
+NRT are serialized as:
+* `null` if `Null`
+* `object` if `NonNull` object
+
+:warning: As of now, NRT can't be considered `null` when deserializing if value is missing.
+
 # License
 The contents of this library are made available under the [Apache License, Version 2.0][license].
 

Diff for: tests/FSharp.MongoDB.Bson.Tests/FSharp.MongoDB.Bson.Tests.fsproj

@@ -12,6 +12,7 @@
     <Compile Include="Serialization\FSharpListSerializationTests.fs" />
     <Compile Include="Serialization\FSharpMapSerializationTests.fs" />
     <Compile Include="Serialization\FSharpOptionSerializationTests.fs" />
+    <Compile Include="Serialization\FSharpNRTSerializationTests.fs" />
     <Compile Include="Serialization\FSharpValueOptionSerializationTests.fs" />
     <Compile Include="Serialization\FSharpRecordSerializationTests.fs" />
     <Compile Include="Serialization\FSharpSetSerializationTests.fs" />

Diff for: tests/FSharp.MongoDB.Bson.Tests/Serialization/FSharpNRTSerializationTests.fs

@@ -0,0 +1,63 @@
+(*
+ * 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.
+ *)
+
+namespace FSharp.MongoDB.Bson.Tests.Serialization
+
+open MongoDB.Bson
+open FsUnit
+open NUnit.Framework
+
+module FSharpNRTSerialization =
+
+    type Primitive =
+        { String : string  | null }
+
+    [<Test>]
+    let ``test serialize nullable reference (null) in a record type``() =
+        let value =  { String = null }
+
+        let result = serialize value
+        let expected = BsonDocument([ BsonElement("String", BsonNull.Value) ])
+
+        result |> should equal expected
+
+    [<Test>]
+    let ``test deserialize nullable reference (null) in a record type)``() =
+        // FIXME: this shall support deserializing missing null value for NRT
+        //        as of now this means NRT can't be a missing value while deserializing
+        // let doc = BsonDocument()
+        let doc = BsonDocument([ BsonElement("String", BsonNull.Value) ])
+
+        let result = deserialize<Primitive> doc
+        let expected = { String = null }
+
+        result |> should equal expected
+
+    [<Test>]
+    let ``test serialize nullable reference (some) in a record type``() =
+        let value =  { String = "A String" }
+
+        let result = serialize value
+        let expected = BsonDocument([ BsonElement("String", BsonString "A String") ])
+
+        result |> should equal expected
+
+    [<Test>]
+    let ``test deserialize nullable reference (some) in a record type``() =
+        let doc = BsonDocument([ BsonElement("String", BsonString "A String") ])
+
+        let result = deserialize<Primitive> doc
+        let expected = { String = "A String" }
+
+        result |> should equal expected

Diff for: tests/FSharp.MongoDB.Bson.Tests/Serialization/FSharpValueOptionSerializationTests.fs

@@ -1,5 +1,4 @@
-(* Copyright (c) 2015 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