Add support for option parameters

Merge #4 a=@mre r=@nox
________________________________________________________________________

1 files changed, 27 insertions, 0 deletions

diff --git a/tests/test_serialize.rs b/tests/test_serialize.rs
new file mode 100644
index 0000000..20592fc
--- /dev/null
+++ b/tests/test_serialize.rs
@@ -0,0 +1,27 @@
+extern crate serde_urlencoded;
+
+#[test]
+fn serialize_option_map_int() {
+    let params = &[
+        ("first", Some(23)),
+        ("middle", None),
+        ("last", Some(42)),
+    ];
+
+    assert_eq!(
+        serde_urlencoded::to_string(params),
+        Ok("first=23&last=42".to_owned()));
+}
+
+#[test]
+fn serialize_option_map_string() {
+    let params = &[
+        ("first", Some("hello")),
+        ("middle", None),
+        ("last", Some("world")),
+    ];
+
+    assert_eq!(
+        serde_urlencoded::to_string(params),
+        Ok("first=hello&last=world".to_owned()));
+}