before not working as expected

[morgante]

---
level: error
---

# Use CamelCase Serialialization

We primarily use TypeScript on the other end, so all serialized structs should be in CamelCase.

```grit
language rust

`#[derive($derive)]` as $attr where {
  $derive <: contains `Serialize`,
  $attr <: not before `#[serde(rename_all = "camelCase")]`,
  $attr += `#[serde(rename_all = "camelCase")]`
}

Basic Example

Before:

#[cfg_attr(feature = "napi", napi_derive::napi(object))]
#[derive(Debug, Clone, Serialize, PartialEq)]
pub struct FileDiff {
    pub old_path: Option<String>,
    pub new_path: Option<String>,
    pub ranges: Vec<RangePair>,
}

Fixed:

#[cfg_attr(feature = "napi", napi_derive::napi(object))]
#[derive(Debug, Clone, Serialize, PartialEq)]
#[serde(rename_all = "camelCase")]
pub struct FileDiff {
    pub old_path: Option<String>,
    pub new_path: Option<String>,
    pub ranges: Vec<RangePair>,
}

Countercase

If you need to serialize a struct in a different case, you can use the #[serde(rename_all = "camelCase")] attribute.

#[cfg_attr(feature = "napi", napi_derive::napi(object))]
#[derive(Debug, Clone, Serialize, PartialEq)]
#[serde(rename_all = "camelCase")]
pub struct FileDiff {
    pub oldPath: Option<String>,
    pub newPath: Option<String>,
    pub ranges: Vec<RangePair>,
}

#[cfg_attr(feature = "napi", napi_derive::napi(object))]
#[derive(Debug, Clone, Serialize, PartialEq)]
#[serde(rename_all = "camelCase")]
pub struct FileDiff {
    pub oldPath: Option<String>,
    pub newPath: Option<String>,
    pub ranges: Vec<RangePair>,
}