Fix serialisation bug with one-field json

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "nanoserde"
-version = "0.1.17"
+version = "0.1.18"
 authors = ["makepad <[email protected]>", "Fedor <[email protected]>"]
 license = "MIT OR Apache-2.0"
 description = """
@@ -22,4 +22,4 @@ edition = "2018"
 repository = "https://github.com/not-fl3/nanoserde"
 
 [dependencies]
-nanoserde-derive = { path = "derive", version = "=0.1.11" }
+nanoserde-derive = { path = "derive", version = "=0.1.12" }

derive/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "nanoserde-derive"
-version = "0.1.11"
+version = "0.1.12"
 authors = ["Makepad <[email protected]>", "Fedor <[email protected]>"]
 edition = "2018"
 description = "Fork of makepad-tinyserde derive without any external dependencies"

derive/src/serde_json.rs

@@ -21,7 +21,7 @@ pub fn derive_ser_json_proxy(proxy_type: &str, type_: &str) -> TokenStream {
 pub fn derive_ser_json_struct(struct_: &Struct) -> TokenStream {
     let mut s = String::new();
 
-    if struct_.fields.len() > 1 {
+    if struct_.fields.len() >= 1 {
         let last = struct_.fields.len() - 1;
         for (index, field) in struct_.fields.iter().enumerate() {
             let struct_fieldname = field.field_name.clone().unwrap();

tests/json.rs

@@ -179,6 +179,19 @@ fn empty() {
     let _: Empty = DeJson::deserialize_json(json).unwrap();
 }
 
+#[test]
+fn one_field() {
+    #[derive(DeJson, SerJson, PartialEq)]
+    pub struct OneField {
+        field: f32,
+    }
+
+    let test = OneField { field: 23. };
+    let bytes = SerJson::serialize_json(&test);
+    let test_deserialized = DeJson::deserialize_json(&bytes).unwrap();
+    assert!(test == test_deserialized);
+}
+
 #[test]
 fn array() {
     #[derive(DeJson)]