Introduce support for nested objects

Test/Flurl.Test/CommonExtensionsTests.cs

@@ -25,6 +25,18 @@ public void can_parse_object_to_kv()
 			}, kv);
 		}
 
+		[Test]
+		public void can_parse_nested_object_to_kv() {
+			var kv = new {
+				one = new { two = "foo", three = new { four = "bar"}},
+			}.ToKeyValuePairs();
+
+			CollectionAssert.AreEquivalent(new Dictionary<string, object> {
+				{ "one.two", "foo" },
+				{ "one.three.four", "bar" },
+			}, kv);
+		}
+
 		[Test]
 		public void can_parse_dictionary_to_kv()
 		{
@@ -91,6 +103,16 @@ public void can_parse_string_to_kv()
 			}, kv);
 		}
 
+		[Test]
+		public void can_parse_string_with_nested_objects_to_kv() {
+			var kv = "one.two=foo&one.three.four=bar".ToKeyValuePairs();
+
+			CollectionAssert.AreEquivalent(new Dictionary<string, object> {
+				{ "one.two", "foo" },
+				{ "one.three.four", "bar" }
+			}, kv);
+		}
+
 		[Test]
 		public void cannot_parse_null_to_kv()
 		{

Test/Flurl.Test/Http/RealHttpTests.cs

@@ -270,7 +270,7 @@ public void can_set_timeout_and_cancellation_token() {
 				cts.Cancel();
 				await task;
 			});
-			Assert.That(ex.InnerException is TaskCanceledException);
+			Assert.That(ex.InnerException is OperationCanceledException);
 			Assert.IsTrue(cts.Token.IsCancellationRequested);
 
 			// timeout with cancellation token set
@@ -280,7 +280,7 @@ public void can_set_timeout_and_cancellation_token() {
 					.WithTimeout(TimeSpan.FromMilliseconds(50))
 					.GetAsync(cts.Token);
 			});
-			Assert.That(ex.InnerException is TaskCanceledException);
+			Assert.That(ex.InnerException is OperationCanceledException);
 			Assert.IsFalse(cts.Token.IsCancellationRequested);
 		}
 

Test/Flurl.Test/UrlBuilderTests.cs

@@ -514,5 +514,25 @@ public void clone_creates_copy() {
 			Assert.AreEqual("http://mysite.com?x=1&z=3", url1.ToString());
 			Assert.AreEqual("http://mysite.com/foo?x=1&y=2", url2.ToString());
 		}
+
+		[Test]
+		public void set_query_params_can_parse_nested_object() {
+			var url = "http://www.mysite.com".SetQueryParams(new {
+				x = 1,
+				y = 2,
+				z = new { a = 3, b = 4 }
+			});
+			Assert.AreEqual("http://www.mysite.com?x=1&y=2&z.a=3&z.b=4", url.ToString());
+		}
+
+		[Test]
+		public void set_query_params_can_parse_second_level_nested_objects() {
+			var url = "http://www.mysite.com".SetQueryParams(new {
+				x = 1,
+				y = 2,
+				z = new { a = new { b = 3 } }
+			});
+			Assert.AreEqual("http://www.mysite.com?x=1&y=2&z.a.b=3", url.ToString());
+		}
 	}
 }

src/Flurl/Util/CommonExtensions.cs

@@ -4,9 +4,7 @@
 using System.Globalization;
 using System.Linq;
 using System.Text.RegularExpressions;
-#if !NET40
 using System.Reflection;
-#endif
 
 namespace Flurl.Util
 {
@@ -73,19 +71,63 @@ private static IEnumerable<KeyValuePair<string, object>> StringToKV(string s) {
 			return Url.ParseQueryParams(s).Select(p => new KeyValuePair<string, object>(p.Name, p.Value));
 		}
 
-		private static IEnumerable<KeyValuePair<string, object>> ObjectToKV(object obj) {
+		private static IEnumerable<KeyValuePair<string, object>> ObjectToKV(object obj, string prefix = "") {
+			var objProperties = new List<KeyValuePair<PropertyInfo, object>>();
+
 #if NETSTANDARD1_0
-			return from prop in obj.GetType().GetRuntimeProperties()
-				let getter = prop.GetMethod
-				where getter?.IsPublic == true
-				let val = getter.Invoke(obj, null)
-				select new KeyValuePair<string, object>(prop.Name, val);
+			objProperties.AddRange(obj
+				.GetType()
+				.GetRuntimeProperties()
+				.Where(p => p.GetMethod.IsPublic)
+				.Select(p =>
+					new KeyValuePair<PropertyInfo, object>(p , p.GetMethod.Invoke(obj, null))
+				));
+
 #else
-			return from prop in obj.GetType().GetProperties()
-				let getter = prop.GetGetMethod(false)
-				where getter != null
-				let val = getter.Invoke(obj, null)
-				select new KeyValuePair<string, object>(prop.Name, val);
+			objProperties.AddRange(obj
+				.GetType()
+				.GetProperties()
+				.Where(p=>p.GetGetMethod(false) != null)
+				.Select(p =>
+					new KeyValuePair<PropertyInfo, object>(p, p.GetGetMethod(false).Invoke(obj, null))
+				));
+#endif
+
+			foreach (var prop in objProperties) {
+				var propertyName = prop.Key.Name;
+				var propertyPath = $"{prefix}{propertyName}";
+				if (prop.Value is IEnumerable || prop.Value?.GetType()?.IsSimple() != false) {
+					yield return new KeyValuePair<string, object>(propertyPath, prop.Value);
+				}
+				else {
+					foreach (var kv in ObjectToKV(prop.Value, $"{propertyPath}."))
+						yield return kv;
+				}
+			}
+		}
+
+		// Credits to Stefan Steinegger, https://stackoverflow.com/a/863944/2001970
+		private static bool IsSimple(this Type type) {
+#if NET40
+			if (type.IsGenericType && type.GetGenericTypeDefinition() == typeof(Nullable<>)) {
+				// nullable type, check if the nested type is simple.
+				return IsSimple(type.GetGenericArguments()[0]);
+			}
+			return type.IsPrimitive
+			       || type.IsEnum
+			       || type == typeof(string)
+			       || type == typeof(decimal);
+
+#else
+			var typeInfo = type.GetTypeInfo();
+			if (typeInfo.IsGenericType && typeInfo.GetGenericTypeDefinition() == typeof(Nullable<>)) {
+				// nullable type, check if the nested type is simple.
+				return IsSimple(typeInfo.GenericTypeArguments[0]);
+			}
+			return typeInfo.IsPrimitive
+			       || typeInfo.IsEnum
+			       || type == typeof(string)
+			       || type == typeof(decimal);
 #endif
 		}