Added interfaces for all the models

src/Tesla.NET/Models/AccessTokenResponse.cs

@@ -5,13 +5,12 @@ namespace Tesla.NET.Models
 {
     using System;
     using System.Diagnostics;
-    using Newtonsoft.Json;
 
     /// <summary>
     /// The response to an access token or refresh token request.
     /// </summary>
     [DebuggerDisplay("{DebuggerDisplay,nq}")]
-    public class AccessTokenResponse
+    public class AccessTokenResponse : IAccessTokenResponse
     {
         /// <summary>
         /// Initializes a new instance of the <see cref="AccessTokenResponse"/> class.
@@ -40,49 +39,41 @@ public AccessTokenResponse(
         /// <summary>
         /// Gets the access token.
         /// </summary>
-        [JsonProperty("access_token")]
         public string AccessToken { get; }
 
         /// <summary>
         /// Gets the type of the <see cref="AccessToken"/>.
         /// </summary>
-        [JsonProperty("token_type")]
         public string TokenType { get; }
 
         /// <summary>
         /// Gets the expiry duration in seconds of the <see cref="AccessToken"/>.
         /// </summary>
-        [JsonProperty("expires_in")]
         public long ExpiresIn { get; }
 
         /// <summary>
         /// Gets the expiry duration of the <see cref="AccessToken"/>.
         /// </summary>
-        [JsonIgnore]
         public TimeSpan ExpiresInTimespan => TimeSpan.FromSeconds(ExpiresIn);
 
         /// <summary>
         /// Gets the UTC <see cref="DateTime"/> when the <see cref="AccessToken"/> expires.
         /// </summary>
-        [JsonIgnore]
         public DateTime ExpiresUtc => EpochConversion.FromSeconds(CreatedAt + ExpiresIn);
 
         /// <summary>
         /// Gets the Epoch timestamp when the <see cref="AccessToken"/> was issued.
         /// </summary>
-        [JsonProperty("created_at")]
         public long CreatedAt { get; }
 
         /// <summary>
         /// Gets the UTC <see cref="DateTime"/> when the <see cref="AccessToken"/> was issued.
         /// </summary>
-        [JsonIgnore]
         public DateTime CreatedUtc => EpochConversion.FromSeconds(CreatedAt);
 
         /// <summary>
         /// Gets the refresh token that can be used to acquire a new <see cref="AccessToken"/>.
         /// </summary>
-        [JsonProperty("refresh_token")]
         public string RefreshToken { get; }
 
         private string DebuggerDisplay => $"{GetType().Name}: {AccessToken.Substring(0, 6)}… Expires {ExpiresUtc:R}";

src/Tesla.NET/Models/IAccessTokenResponse.cs

@@ -0,0 +1,62 @@
+// Copyright (c) 2018 James Skimming. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See LICENSE in the project root for license information.
+
+namespace Tesla.NET.Models
+{
+    using System;
+    using Newtonsoft.Json;
+
+    /// <summary>
+    /// The response to an access token or refresh token request.
+    /// </summary>
+    public interface IAccessTokenResponse
+    {
+        /// <summary>
+        /// Gets the access token.
+        /// </summary>
+        [JsonProperty("access_token")]
+        string AccessToken { get; }
+
+        /// <summary>
+        /// Gets the type of the <see cref="AccessToken"/>.
+        /// </summary>
+        [JsonProperty("token_type")]
+        string TokenType { get; }
+
+        /// <summary>
+        /// Gets the expiry duration in seconds of the <see cref="AccessToken"/>.
+        /// </summary>
+        [JsonProperty("expires_in")]
+        long ExpiresIn { get; }
+
+        /// <summary>
+        /// Gets the expiry duration of the <see cref="AccessToken"/>.
+        /// </summary>
+        [JsonIgnore]
+        TimeSpan ExpiresInTimespan { get; }
+
+        /// <summary>
+        /// Gets the UTC <see cref="DateTime"/> when the <see cref="AccessToken"/> expires.
+        /// </summary>
+        [JsonIgnore]
+        DateTime ExpiresUtc { get; }
+
+        /// <summary>
+        /// Gets the Epoch timestamp when the <see cref="AccessToken"/> was issued.
+        /// </summary>
+        [JsonProperty("created_at")]
+        long CreatedAt { get; }
+
+        /// <summary>
+        /// Gets the UTC <see cref="DateTime"/> when the <see cref="AccessToken"/> was issued.
+        /// </summary>
+        [JsonIgnore]
+        DateTime CreatedUtc { get; }
+
+        /// <summary>
+        /// Gets the refresh token that can be used to acquire a new <see cref="AccessToken"/>.
+        /// </summary>
+        [JsonProperty("refresh_token")]
+        string RefreshToken { get; }
+    }
+}

src/Tesla.NET/Models/IMessageResponse.Generic.cs

@@ -0,0 +1,20 @@
+// Copyright (c) 2018 James Skimming. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See LICENSE in the project root for license information.
+
+namespace Tesla.NET.Models
+{
+    using System;
+
+    /// <summary>
+    /// The message response from the Tesla Owner API.
+    /// </summary>
+    /// <typeparam name="TData">The <see cref="Type"/> of the <see cref="Data"/>.</typeparam>
+    public interface IMessageResponse<out TData> : IMessageResponse
+        where TData : class
+    {
+        /// <summary>
+        /// Gets the <typeparamref name="TData"/> object.
+        /// </summary>
+        TData Data { get; }
+    }
+}

src/Tesla.NET/Models/IMessageResponse.cs

@@ -0,0 +1,31 @@
+// Copyright (c) 2018 James Skimming. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See LICENSE in the project root for license information.
+
+namespace Tesla.NET.Models
+{
+    using System.Net;
+    using Newtonsoft.Json;
+    using Newtonsoft.Json.Linq;
+
+    /// <summary>
+    /// The message response from the Tesla Owner API.
+    /// </summary>
+    public interface IMessageResponse
+    {
+        /// <summary>
+        /// Gets the <see cref="HttpStatusCode"/>.
+        /// </summary>
+        HttpStatusCode HttpStatusCode { get; }
+
+        /// <summary>
+        /// Gets the raw JSON of the <see cref="IMessageResponse"/>.
+        /// </summary>
+        JObject RawJson { get; }
+
+        /// <summary>
+        /// Gets the raw JSON of the <see cref="IMessageResponse"/>.
+        /// </summary>
+        [JsonIgnore]
+        string RawJsonAsString { get; }
+    }
+}

src/Tesla.NET/Models/IResponseDataWrapper.cs

@@ -0,0 +1,21 @@
+// Copyright (c) 2018 James Skimming. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See LICENSE in the project root for license information.
+
+namespace Tesla.NET.Models
+{
+    using System;
+    using Newtonsoft.Json;
+
+    /// <summary>
+    /// The wrapper object for a response from the Tesla Owner API.
+    /// </summary>
+    /// <typeparam name="TResponse">The <see cref="Type"/> of the <see cref="Response"/>.</typeparam>
+    public interface IResponseDataWrapper<out TResponse>
+    {
+        /// <summary>
+        /// Gets the <typeparamref name="TResponse"/> object.
+        /// </summary>
+        [JsonProperty("response")]
+        TResponse Response { get; }
+    }
+}

src/Tesla.NET/Models/MessageResponse.cs

@@ -14,7 +14,7 @@ namespace Tesla.NET.Models
     /// </summary>
     /// <typeparam name="TData">The <see cref="Type"/> of the <see cref="Data"/>.</typeparam>
     [DebuggerDisplay("{DebuggerDisplay,nq}")]
-    public class MessageResponse<TData>
+    public class MessageResponse<TData> : IMessageResponse<TData>
         where TData : class
     {
         private readonly JObject _rawJson;
@@ -38,14 +38,13 @@ public MessageResponse(HttpStatusCode httpStatusCode, JObject rawJson = null, TD
         public HttpStatusCode HttpStatusCode { get; }
 
         /// <summary>
-        /// Gets the raw JSON of the <see cref="Data"/>.
+        /// Gets the raw JSON of the <see cref="IMessageResponse"/>.
         /// </summary>
         public JObject RawJson => (JObject)_rawJson?.DeepClone();
 
         /// <summary>
-        /// Gets the raw JSON of the <see cref="Data"/>.
+        /// Gets the raw JSON of the <see cref="IMessageResponse"/>.
         /// </summary>
-        [JsonIgnore]
         public string RawJsonAsString => _rawJson?.ToString(Formatting.None) ?? string.Empty;
 
         /// <summary>

src/Tesla.NET/Models/ResponseDataWrapper.cs

@@ -5,14 +5,13 @@ namespace Tesla.NET.Models
 {
     using System;
     using System.Diagnostics;
-    using Newtonsoft.Json;
 
     /// <summary>
     /// The wrapper object for a response from the Tesla Owner API.
     /// </summary>
     /// <typeparam name="TResponse">The <see cref="Type"/> of the <see cref="Response"/>.</typeparam>
     [DebuggerDisplay("{DebuggerDisplay,nq}")]
-    public class ResponseDataWrapper<TResponse>
+    public class ResponseDataWrapper<TResponse> : IResponseDataWrapper<TResponse>
     {
         /// <summary>
         /// Initializes a new instance of the <see cref="ResponseDataWrapper{TResponse}"/> class.
@@ -26,7 +25,6 @@ public ResponseDataWrapper(TResponse response = default)
         /// <summary>
         /// Gets the <typeparamref name="TResponse"/> object.
         /// </summary>
-        [JsonProperty("response")]
         public TResponse Response { get; }
 
         private string DebuggerDisplay => $"{GetType().Name}: {typeof(TResponse).Name}";