bomboni: wasm_derive

Provides derive macros for generating TypeScript WASM bindings for Rust types.

This crate offers the Wasm derive macro that generates code to make Rust types usable in JavaScript/TypeScript environments through wasm-bindgen, with automatic TypeScript type generation.

Features

• Automatic TypeScript type generation
• wasm-bindgen integration
• Custom type conversions
• Enum value objects
• Proxy types for complex conversions
• Reference type mapping
• Field and variant renaming
• Custom crate path configuration
• JsValue conversion support

Quick Start

use bomboni_wasm_derive::Wasm;

#[derive(Wasm)]
#[wasm(rename = "User", into_wasm_abi = true, from_wasm_abi = true)]
struct User {
    #[wasm(rename = "userName")]
    name: String,

    #[wasm(override_type = "Date")]
    created_at: /* DateTime<Utc> */,

    #[wasm(always_some = true)]
    optional_field: Option<String>,
}

Generated Output

The macro generates:

• TypeScript type definitions
• wasm-bindgen bindings
• Conversion traits (FromWasmAbi, IntoWasmAbi, etc.)
• Error handling for WASM conversions

Struct Options

The #[wasm(...)] attribute can be applied to structs to control overall behavior:

• rename = "Name" - Custom name in TypeScript
• into_wasm_abi = bool - Generate IntoWasmAbi implementation
• from_wasm_abi = bool - Generate FromWasmAbi implementation
• wasm_abi = bool - Generate both IntoWasmAbi and FromWasmAbi
• enum_value = bool - Generate enum value object (for enums)
• js_value(...) - Custom JsValue conversion
• proxy = Type - Use proxy type for conversions
• rename_all = "rule" - Rename rule for all fields
• override_type = "string" - Override generated TypeScript type
• change_ref = "mapping" - Reference type mapping
• *_crate = "path" - Custom crate paths

Field Options

The #[wasm(...)] attribute can be applied to fields:

• rename = "name" - Custom field name in TypeScript
• override_type = "type" - Override field type
• rename_wrapper = bool - Control wrapper type renaming
• always_some = bool - Force field to be required in TypeScript
• change_ref = "mapping" - Reference type mapping for field

Advanced Examples

Custom JsValue Conversions

#[derive(Wasm)]
#[wasm(js_value(
    into = MyType::to_js_value,
    try_from = MyType::from_js_value,
))]
struct MyType {
    value: String,
}

impl MyType {
    fn to_js_value(self) -> /* JsValue */ {
        // Custom conversion logic
    }

    fn from_js_value(value: &/* JsValue */) -> Result<Self, /* JsValue */> {
        // Custom conversion logic
    }
}

String Conversions

#[derive(Wasm)]
#[wasm(js_value(convert_string))]
struct UserId(String);

#[derive(Wasm)]
#[wasm(js_value(convert_string))]
struct Email(String);

Proxy Types

#[derive(Wasm)]
#[wasm(proxy = UserProxy)]
struct User {
    id: u32,
    name: String,
}

// With custom conversions
#[derive(Wasm)]
#[wasm(proxy(
    source = UserProxy,
    into = User::to_proxy,
    try_from = User::from_proxy,
))]
struct User2 {
    id: u32,
    name: String,
}

Enum Value Objects

#[derive(Wasm)]
#[wasm(enum_value = true)]
enum Status {
    #[wasm(rename = "active")]
    Active,

    #[wasm(rename = "inactive")]
    Inactive,
}

Reference Type Mapping

#[derive(Wasm)]
#[wasm(change_ref = "&str -> string")]
struct MyStruct {
    #[wasm(change_ref = "&[u8] -> Uint8Array")]
    data: Vec<u8>,
}

Custom Crate Paths

#[derive(Wasm)]
#[wasm(
    wasm_bindgen_crate = "crate::wasm",
    js_sys_crate = "crate::js",
    bomboni_crate = "crate::internal::bomboni",
)]
struct MyStruct {
    field: String,
}