Merge pull request #155 from erickt/skip

Add skip serializing fields if empty or none

README.md

@@ -17,8 +17,8 @@ Documentation is available at:
 * [serde\_json](https://serde-rs.github.io/serde/serde_json/serde_json/index.html)
 * [serde\_codegen](https://serde-rs.github.io/serde/serde_codegen/serde_codegen/index.html)
 
-Using Serde
+Using Serde with Nightly Rust and serde\_macros
-===========
+===============================================
 
 Here is a simple example that demonstrates how to use Serde by serializing and
 deserializing to JSON. Serde comes with some powerful code generation libraries
@@ -76,6 +76,9 @@ When run, it produces:
 Point { x: 1, y: 2 }
 ```
 
+Using Serde with Stable Rust, syntex, and serde\_codegen
+========================================================
+
 Stable Rust is a little more complicated because it does not yet support
 compiler plugins. Instead we need to use the code generation library
 [syntex](https://github.com/erickt/rust-syntex) for this:
@@ -215,6 +218,19 @@ include!(concat!(env!("OUT_DIR"), "/main.rs"));
 
 The `src/main.rs.in` is the same as before.
 
+Then to run with stable:
+
+```
+% cargo build
+...
+```
+
+Or with nightly:
+
+```rust
+% cargo build --features nightly --no-default-features
+...
+
 Serialization without Macros
 ============================
 
@@ -311,6 +327,8 @@ as a named map. Its visitor uses a simple state machine to iterate through all
 the fields:
 
 ```rust
+extern crate serde;
+
 struct Point {
     x: i32,
     y: i32,
@@ -479,6 +497,13 @@ deserializes an enum variant from a string. So for our `Point` example from
 before, we need to generate:
 
 ```rust
+extern crate serde;
+
+struct Point {
+    x: i32,
+    y: i32,
+}
+
 enum PointField {
     X,
     Y,
@@ -507,11 +532,7 @@ impl serde::Deserialize for PointField {
         deserializer.visit(PointFieldVisitor)
     }
 }
-```
 
-This is then used in our actual deserializer:
-
-```rust
 impl serde::Deserialize for Point {
     fn deserialize<D>(deserializer: &mut D) -> Result<Point, D::Error>
         where D: serde::de::Deserializer
@@ -557,6 +578,21 @@ impl serde::de::Visitor for PointVisitor {
 }
 ```
 
+Annotations
+===========
+
+`serde_codegen` and `serde_macros` support annotations that help to customize
+how types are serialized. Here are the supported annotations:
+
+| Annotation                                   | Function                                                       |
+| ----------                                   | --------                                                       |
+| `#[serde(rename(json="name1", xml="name2"))` | Serialize this field with the given name for the given formats |
+| `#[serde(default)`                           | If the value is not specified, use the `Default::default()`    |
+| `#[serde(rename="name")`                     | Serialize this field with the given name                       |
+| `#[serde(skip_serializing)`                  | Do not serialize this value                                    |
+| `#[serde(skip_serializing_if_empty)`         | Do not serialize this value if `$value.is_empty()` is `true`   |
+| `#[serde(skip_serializing_if_none)`          | Do not serialize this value if `$value.is_none()` is `true`    |
+
 Serialization Formats Using Serde
 =================================
 

serde/src/ser/mod.rs

@@ -337,7 +337,7 @@ pub trait SeqVisitor {
     }
 }
 
-/// A trait that is used by a `Serializer` to iterate through a map.
+/// A trait that is used by a `Serialize` to iterate through a map.
 pub trait MapVisitor {
     /// Serializes a map item in the serializer.
     ///

serde_codegen/src/attr.rs

@@ -2,10 +2,14 @@ use std::collections::HashMap;
 use std::collections::HashSet;
 
 use syntax::ast;
+use syntax::attr;
 use syntax::ext::base::ExtCtxt;
 use syntax::ptr::P;
 
+use aster;
+
 /// Represents field name information
+#[derive(Debug)]
 pub enum FieldNames {
     Global(P<ast::Expr>),
     Format{
@@ -15,43 +19,16 @@ pub enum FieldNames {
 }
 
 /// Represents field attribute information
+#[derive(Debug)]
 pub struct FieldAttrs {
     skip_serializing_field: bool,
+    skip_serializing_field_if_empty: bool,
+    skip_serializing_field_if_none: bool,
     names: FieldNames,
     use_default: bool,
 }
 
 impl FieldAttrs {
-    /// Create a FieldAttr with a single default field name
-    pub fn new(
-        skip_serializing_field: bool,
-        default_value: bool,
-        name: P<ast::Expr>,
-    ) -> FieldAttrs {
-        FieldAttrs {
-            skip_serializing_field: skip_serializing_field,
-            names: FieldNames::Global(name),
-            use_default: default_value,
-        }
-    }
-
-    /// Create a FieldAttr with format specific field names
-    pub fn new_with_formats(
-        skip_serializing_field: bool,
-        default_value: bool,
-        default_name: P<ast::Expr>,
-        formats: HashMap<P<ast::Expr>, P<ast::Expr>>,
-    ) -> FieldAttrs {
-        FieldAttrs {
-            skip_serializing_field: skip_serializing_field,
-            names: FieldNames::Format {
-                formats: formats,
-                default: default_name,
-            },
-            use_default: default_value,
-        }
-    }
-
     /// Return a set of formats that the field has attributes for.
     pub fn formats(&self) -> HashSet<P<ast::Expr>> {
         match self.names {
@@ -70,22 +47,21 @@ impl FieldAttrs {
     ///
     /// The resulting expression assumes that `S` refers to a type
     /// that implements `Serializer`.
-    pub fn serializer_key_expr(self, cx: &ExtCtxt) -> P<ast::Expr> {
+    pub fn serializer_key_expr(&self, cx: &ExtCtxt) -> P<ast::Expr> {
         match self.names {
-            FieldNames::Global(x) => x,
+            FieldNames::Global(ref name) => name.clone(),
-            FieldNames::Format{formats, default} => {
+            FieldNames::Format { ref formats, ref default } => {
                 let arms = formats.iter()
                     .map(|(fmt, lit)| {
                         quote_arm!(cx, $fmt => { $lit })
                     })
                     .collect::<Vec<_>>();
                 quote_expr!(cx,
-                            {
+                    match S::format() {
-                                match S::format() {
+                        $arms
-                                    $arms
+                        _ => { $default }
-                                    _ => { $default }
+                    }
-                                }
+                )
-                            })
             },
         }
     }
@@ -94,17 +70,17 @@ impl FieldAttrs {
     pub fn default_key_expr(&self) -> &P<ast::Expr> {
         match self.names {
             FieldNames::Global(ref expr) => expr,
-            FieldNames::Format{formats: _, ref default} => default
+            FieldNames::Format{formats: _, ref default} => default,
         }
     }
 
     /// Return the field name for the field in the specified format.
     pub fn key_expr(&self, format: &P<ast::Expr>) -> &P<ast::Expr> {
         match self.names {
-            FieldNames::Global(ref expr) =>
+            FieldNames::Global(ref expr) => expr,
-                expr,
+            FieldNames::Format { ref formats, ref default } => {
-            FieldNames::Format{ref formats, ref default} =>
                 formats.get(format).unwrap_or(default)
+            }
         }
     }
 
@@ -117,4 +93,153 @@ impl FieldAttrs {
     pub fn skip_serializing_field(&self) -> bool {
         self.skip_serializing_field
     }
+
+    pub fn skip_serializing_field_if_empty(&self) -> bool {
+        self.skip_serializing_field_if_empty
+    }
+
+    pub fn skip_serializing_field_if_none(&self) -> bool {
+        self.skip_serializing_field_if_none
+    }
+}
+
+pub struct FieldAttrsBuilder<'a> {
+    builder: &'a aster::AstBuilder,
+    skip_serializing_field: bool,
+    skip_serializing_field_if_empty: bool,
+    skip_serializing_field_if_none: bool,
+    name: Option<P<ast::Expr>>,
+    format_rename: HashMap<P<ast::Expr>, P<ast::Expr>>,
+    use_default: bool,
+}
+
+impl<'a> FieldAttrsBuilder<'a> {
+    pub fn new(builder: &'a aster::AstBuilder) -> FieldAttrsBuilder<'a> {
+        FieldAttrsBuilder {
+            builder: builder,
+            skip_serializing_field: false,
+            skip_serializing_field_if_empty: false,
+            skip_serializing_field_if_none: false,
+            name: None,
+            format_rename: HashMap::new(),
+            use_default: false,
+        }
+    }
+
+    pub fn field(mut self, field: &ast::StructField) -> FieldAttrsBuilder<'a> {
+        match field.node.kind {
+            ast::NamedField(name, _) => {
+                self.name = Some(self.builder.expr().str(name));
+            }
+            ast::UnnamedField(_) => { }
+        };
+
+        self.attrs(&field.node.attrs)
+    }
+
+    pub fn attrs(self, attrs: &[ast::Attribute]) -> FieldAttrsBuilder<'a> {
+        attrs.iter().fold(self, FieldAttrsBuilder::attr)
+    }
+
+    pub fn attr(self, attr: &ast::Attribute) -> FieldAttrsBuilder<'a> {
+        match attr.node.value.node {
+            ast::MetaList(ref name, ref items) if name == &"serde" => {
+                attr::mark_used(&attr);
+                items.iter().fold(self, FieldAttrsBuilder::meta_item)
+            }
+            _ => {
+                self
+            }
+        }
+    }
+
+    pub fn meta_item(mut self, meta_item: &P<ast::MetaItem>) -> FieldAttrsBuilder<'a> {
+        match meta_item.node {
+            ast::MetaNameValue(ref name, ref lit) if name == &"rename" => {
+                let expr = self.builder.expr().build_lit(P(lit.clone()));
+
+                self.name(expr)
+            }
+            ast::MetaList(ref name, ref items) if name == &"rename" => {
+                for item in items {
+                    match item.node {
+                        ast::MetaNameValue(ref name, ref lit) => {
+                            let name = self.builder.expr().str(name);
+                            let expr = self.builder.expr().build_lit(P(lit.clone()));
+
+                            self = self.format_rename(name, expr);
+                        }
+                        _ => { }
+                    }
+                }
+                self
+            }
+            ast::MetaWord(ref name) if name == &"default" => {
+                self.default()
+            }
+            ast::MetaWord(ref name) if name == &"skip_serializing" => {
+                self.skip_serializing_field()
+            }
+            ast::MetaWord(ref name) if name == &"skip_serializing_if_empty" => {
+                self.skip_serializing_field_if_empty()
+            }
+            ast::MetaWord(ref name) if name == &"skip_serializing_if_none" => {
+                self.skip_serializing_field_if_none()
+            }
+            _ => {
+                // Ignore unknown meta variables for now.
+                self
+            }
+        }
+    }
+
+    pub fn skip_serializing_field(mut self) -> FieldAttrsBuilder<'a> {
+        self.skip_serializing_field = true;
+        self
+    }
+
+    pub fn skip_serializing_field_if_empty(mut self) -> FieldAttrsBuilder<'a> {
+        self.skip_serializing_field_if_empty = true;
+        self
+    }
+
+    pub fn skip_serializing_field_if_none(mut self) -> FieldAttrsBuilder<'a> {
+        self.skip_serializing_field_if_none = true;
+        self
+    }
+
+    pub fn name(mut self, name: P<ast::Expr>) -> FieldAttrsBuilder<'a> {
+        self.name = Some(name);
+        self
+    }
+
+    pub fn format_rename(mut self, format: P<ast::Expr>, name: P<ast::Expr>) -> FieldAttrsBuilder<'a> {
+        self.format_rename.insert(format, name);
+        self
+    }
+
+    pub fn default(mut self) -> FieldAttrsBuilder<'a> {
+        self.use_default = true;
+        self
+    }
+
+    pub fn build(self) -> FieldAttrs {
+        let name = self.name.expect("here");
+        let names = if self.format_rename.is_empty() {
+            FieldNames::Global(name)
+        } else {
+            FieldNames::Format {
+                formats: self.format_rename,
+                default: name,
+            }
+        };
+
+        FieldAttrs {
+            skip_serializing_field: self.skip_serializing_field,
+            skip_serializing_field_if_empty: self.skip_serializing_field_if_empty,
+            skip_serializing_field_if_none: self.skip_serializing_field_if_none,
+            names: names,
+            use_default: self.use_default,
+        }
+    }
 }

serde_codegen/src/de.rs

@@ -543,11 +543,13 @@ fn deserialize_item_enum(
         cx,
         builder,
         enum_def.variants.iter()
-            .map(|variant|
+            .map(|variant| {
-                 attr::FieldAttrs::new(
+                let expr = builder.expr().str(variant.node.name);
-                     false,
+                 attr::FieldAttrsBuilder::new(builder)
-                     true,
+                    .name(expr)
-                     builder.expr().str(variant.node.name)))
+                    .default()
+                    .build()
+            })
             .collect()
     );
 

serde_codegen/src/field.rs

@@ -1,147 +1,17 @@
-use std::collections::HashMap;
+use syntax::ast;
+use syntax::ext::base::ExtCtxt;
 
 use aster;
-
+use attr::{FieldAttrs, FieldAttrsBuilder};
-use syntax::ast;
-use syntax::attr;
-use syntax::ext::base::ExtCtxt;
-use syntax::ptr::P;
-
-use attr::FieldAttrs;
-
-enum Rename<'a> {
-    None,
-    Global(&'a ast::Lit),
-    Format(HashMap<P<ast::Expr>, &'a ast::Lit>)
-}
-
-fn rename<'a>(
-    builder: &aster::AstBuilder,
-    mi: &'a ast::MetaItem,
-    ) -> Option<Rename<'a>>
-{
-    match mi.node {
-        ast::MetaNameValue(ref n, ref lit) => {
-            if n == &"rename" {
-                Some(Rename::Global(lit))
-            } else {
-                None
-            }
-        },
-        ast::MetaList(ref n, ref items) => {
-            if n == &"rename" {
-                let mut m = HashMap::new();
-                m.extend(
-                    items.iter()
-                        .filter_map(
-                            |item|
-                            match item.node {
-                                ast::MetaNameValue(ref n, ref lit) =>
-                                    Some((builder.expr().str(n),
-                                          lit)),
-                                _ => None
-                            }));
-                Some(Rename::Format(m))
-            } else {
-                None
-            }
-        },
-        _ => None
-    }
-}
-
-fn default_value(mi: &ast::MetaItem) -> bool {
-    if let ast::MetaItem_::MetaWord(ref n) = mi.node {
-        n == &"default"
-    } else {
-        false
-    }
-}
-
-fn skip_serializing_field(mi: &ast::MetaItem) -> bool {
-    if let ast::MetaItem_::MetaWord(ref n) = mi.node {
-        n == &"skip_serializing"
-    } else {
-        false
-    }
-}
-
-fn field_attrs<'a>(
-    builder: &aster::AstBuilder,
-    field: &'a ast::StructField,
-) -> (Rename<'a>, bool, bool) {
-    field.node.attrs.iter()
-        .find(|sa| {
-            if let ast::MetaList(ref n, _) = sa.node.value.node {
-                n == &"serde"
-            } else {
-                false
-            }
-        })
-        .and_then(|sa| {
-            if let ast::MetaList(_, ref vals) = sa.node.value.node {
-                attr::mark_used(&sa);
-                Some((
-                    vals.iter()
-                        .fold(None, |v, mi| v.or(rename(builder, mi)))
-                        .unwrap_or(Rename::None),
-                    vals.iter().any(|mi| default_value(mi)),
-                    vals.iter().any(|mi| skip_serializing_field(mi)),
-                ))
-            } else {
-                Some((Rename::None, false, false))
-            }
-        })
-        .unwrap_or((Rename::None, false, false))
-}
 
 pub fn struct_field_attrs(
-    cx: &ExtCtxt,
+    _cx: &ExtCtxt,
     builder: &aster::AstBuilder,
     struct_def: &ast::StructDef,
 ) -> Vec<FieldAttrs> {
     struct_def.fields.iter()
         .map(|field| {
-            match field_attrs(builder, field) {
+            FieldAttrsBuilder::new(builder).field(field).build()
-                (Rename::Global(rename), default_value, skip_serializing_field) =>
-                    FieldAttrs::new(
-                        skip_serializing_field,
-                        default_value,
-                        builder.expr().build_lit(P(rename.clone()))),
-                (Rename::Format(renames), default_value, skip_serializing_field) => {
-                    let mut res = HashMap::new();
-                    res.extend(
-                        renames.into_iter()
-                            .map(|(k,v)|
-                                 (k, builder.expr().build_lit(P(v.clone())))));
-                    FieldAttrs::new_with_formats(
-                        skip_serializing_field,
-                        default_value,
-                        default_field_name(cx, builder, field.node.kind),
-                        res)
-                },
-                (Rename::None, default_value, skip_serializing_field) => {
-                    FieldAttrs::new(
-                        skip_serializing_field,
-                        default_value,
-                        default_field_name(cx, builder, field.node.kind))
-                }
-            }
         })
         .collect()
 }
-
-fn default_field_name(
-    cx: &ExtCtxt,
-    builder: &aster::AstBuilder,
-    kind: ast::StructFieldKind,
-) -> P<ast::Expr> {
-    match kind {
-        ast::NamedField(name, _) => {
-            builder.expr().str(name)
-        }
-        ast::UnnamedField(_) => {
-            cx.bug("struct has named and unnamed fields")
-        }
-    }
-}

serde_codegen/src/ser.rs

@@ -580,23 +580,31 @@ fn serialize_struct_visitor<I>(
 ) -> (P<ast::Item>, P<ast::Item>)
     where I: Iterator<Item=P<ast::Expr>>,
 {
+    let value_exprs = value_exprs.collect::<Vec<_>>();
+
     let field_attrs = struct_field_attrs(cx, builder, struct_def);
 
-    let len = struct_def.fields.len() - field_attrs.iter()
+    let arms: Vec<ast::Arm> = field_attrs.iter()
-        .fold(0, |sum, field| {
+        .zip(value_exprs.iter())
-            sum + if field.skip_serializing_field() { 1 } else { 0 }
-        });
-
-    let arms: Vec<ast::Arm> = field_attrs.into_iter()
-        .zip(value_exprs)
         .filter(|&(ref field, _)| !field.skip_serializing_field())
         .enumerate()
-        .map(|(i, (field, value_expr))| {
+        .map(|(i, (ref field, value_expr))| {
             let key_expr = field.serializer_key_expr(cx);
+
+            let stmt = if field.skip_serializing_field_if_empty() {
+                quote_stmt!(cx, if $value_expr.is_empty() { continue; })
+            } else if field.skip_serializing_field_if_none() {
+                quote_stmt!(cx, if $value_expr.is_none() { continue; })
+            } else {
+                quote_stmt!(cx, {})
+            };
+
             quote_arm!(cx,
                 $i => {
                     self.state += 1;
-                    Ok(
+                    $stmt
+
+                    return Ok(
                         Some(
                             try!(
                                 serializer.visit_struct_elt(
@@ -605,7 +613,7 @@ fn serialize_struct_visitor<I>(
                                 )
                             )
                         )
-                    )
+                    );
                 }
             )
         })
@@ -622,6 +630,21 @@ fn serialize_struct_visitor<I>(
         .strip_bounds()
         .build();
 
+    let len = field_attrs.iter()
+        .zip(value_exprs.iter())
+        .map(|(field, value_expr)| {
+            if field.skip_serializing_field() {
+                quote_expr!(cx, 0)
+            } else if field.skip_serializing_field_if_empty() {
+                quote_expr!(cx, if $value_expr.is_empty() { 0 } else { 1 })
+            } else if field.skip_serializing_field_if_none() {
+                quote_expr!(cx, if $value_expr.is_none() { 0 } else { 1 })
+            } else {
+                quote_expr!(cx, 1)
+            }
+        })
+        .fold(quote_expr!(cx, 0), |sum, expr| quote_expr!(cx, $sum + $expr));
+
     (
         quote_item!(cx,
             struct Visitor $visitor_impl_generics $where_clause {
@@ -640,9 +663,11 @@ fn serialize_struct_visitor<I>(
                 fn visit<S>(&mut self, serializer: &mut S) -> ::std::result::Result<Option<()>, S::Error>
                     where S: ::serde::ser::Serializer,
                 {
-                    match self.state {
+                    loop {
-                        $arms
+                        match self.state {
-                        _ => Ok(None)
+                            $arms
+                            _ => { return Ok(None); }
+                        }
                     }
                 }
 

serde_tests/tests/test_annotations.rs

@@ -39,6 +39,20 @@ struct SkipSerializingFields<A: default::Default> {
     b: A,
 }
 
+#[derive(Debug, PartialEq, Deserialize, Serialize)]
+struct SkipSerializingIfEmptyFields<A: default::Default> {
+    a: i8,
+    #[serde(skip_serializing_if_empty, default)]
+    b: Vec<A>,
+}
+
+#[derive(Debug, PartialEq, Deserialize, Serialize)]
+struct SkipSerializingIfNoneFields<A: default::Default> {
+    a: i8,
+    #[serde(skip_serializing_if_none, default)]
+    b: Option<A>,
+}
+
 #[test]
 fn test_default() {
     assert_de_tokens(
@@ -169,3 +183,161 @@ fn test_skip_serializing_fields() {
         ]
     );
 }
+
+#[test]
+fn test_skip_serializing_fields_if_empty() {
+    assert_ser_tokens(
+        &SkipSerializingIfEmptyFields::<i32> {
+            a: 1,
+            b: vec![],
+        },
+        &[
+            Token::StructStart("SkipSerializingIfEmptyFields", Some(1)),
+
+            Token::MapSep,
+            Token::Str("a"),
+            Token::I8(1),
+
+            Token::MapEnd,
+        ]
+    );
+
+    assert_de_tokens(
+        &SkipSerializingIfEmptyFields::<i32> {
+            a: 1,
+            b: vec![],
+        },
+        vec![
+            Token::StructStart("SkipSerializingIfEmptyFields", Some(1)),
+
+            Token::MapSep,
+            Token::Str("a"),
+            Token::I8(1),
+
+            Token::MapEnd,
+        ]
+    );
+
+    assert_ser_tokens(
+        &SkipSerializingIfEmptyFields {
+            a: 1,
+            b: vec![2],
+        },
+        &[
+            Token::StructStart("SkipSerializingIfEmptyFields", Some(2)),
+
+            Token::MapSep,
+            Token::Str("a"),
+            Token::I8(1),
+
+            Token::MapSep,
+            Token::Str("b"),
+            Token::SeqStart(Some(1)),
+            Token::SeqSep,
+            Token::I32(2),
+            Token::SeqEnd,
+
+            Token::MapEnd,
+        ]
+    );
+
+    assert_de_tokens(
+        &SkipSerializingIfEmptyFields {
+            a: 1,
+            b: vec![2],
+        },
+        vec![
+            Token::StructStart("SkipSerializingIfEmptyFields", Some(2)),
+
+            Token::MapSep,
+            Token::Str("a"),
+            Token::I8(1),
+
+            Token::MapSep,
+            Token::Str("b"),
+            Token::SeqStart(Some(1)),
+            Token::SeqSep,
+            Token::I32(2),
+            Token::SeqEnd,
+
+            Token::MapEnd,
+        ]
+    );
+}
+
+#[test]
+fn test_skip_serializing_fields_if_none() {
+    assert_ser_tokens(
+        &SkipSerializingIfNoneFields::<i32> {
+            a: 1,
+            b: None,
+        },
+        &[
+            Token::StructStart("SkipSerializingIfNoneFields", Some(1)),
+
+            Token::MapSep,
+            Token::Str("a"),
+            Token::I8(1),
+
+            Token::MapEnd,
+        ]
+    );
+
+    assert_de_tokens(
+        &SkipSerializingIfNoneFields::<i32> {
+            a: 1,
+            b: None,
+        },
+        vec![
+            Token::StructStart("SkipSerializingIfNoneFields", Some(1)),
+
+            Token::MapSep,
+            Token::Str("a"),
+            Token::I8(1),
+
+            Token::MapEnd,
+        ]
+    );
+
+    assert_ser_tokens(
+        &SkipSerializingIfNoneFields {
+            a: 1,
+            b: Some(2),
+        },
+        &[
+            Token::StructStart("SkipSerializingIfNoneFields", Some(2)),
+
+            Token::MapSep,
+            Token::Str("a"),
+            Token::I8(1),
+
+            Token::MapSep,
+            Token::Str("b"),
+            Token::Option(true),
+            Token::I32(2),
+
+            Token::MapEnd,
+        ]
+    );
+
+    assert_de_tokens(
+        &SkipSerializingIfNoneFields {
+            a: 1,
+            b: Some(2),
+        },
+        vec![
+            Token::StructStart("SkipSerializingIfNoneFields", Some(2)),
+
+            Token::MapSep,
+            Token::Str("a"),
+            Token::I8(1),
+
+            Token::MapSep,
+            Token::Str("b"),
+            Token::Option(true),
+            Token::I32(2),
+
+            Token::MapEnd,
+        ]
+    );
+}