ferrotype

Rust-to-TypeScript type generation via derive macro. Generates TypeScript type definitions from Rust structs and enums using an intermediate representation for deduplication and dependency ordering.

Installation

[dependencies]
ferro-type = "0.2.0"

Features

• #[derive(TS)] for structs and enums
• Structured TypeDef IR instead of string concatenation
• TypeRegistry for collecting types and rendering in dependency order
• Serde-compatible attributes (rename, rename_all, skip, flatten, etc.)
• Discriminated union generation for enums
• Support for generics

Usage

Basic Derive

use ferrotype::TS;

#[derive(TS)]
struct User {
    id: String,
    name: String,
    age: i32,
}

// Renders as: { id: string; name: string; age: number }

Enums

use ferrotype::TS;

// Unit variants become string literal unions
#[derive(TS)]
enum Status {
    Pending,
    Active,
    Completed,
}
// Renders as: "Pending" | "Active" | "Completed"

// Data variants become discriminated unions
#[derive(TS)]
enum Message {
    Ping,
    Text(String),
    Error { code: i32, message: String },
}
// Renders as: { type: "Ping" } | { type: "Text"; value: string } | { type: "Error"; code: number; message: string }

TypeRegistry

use ferrotype::{TS, TypeRegistry};

#[derive(TS)]
struct User {
    id: String,
    name: String,
}

#[derive(TS)]
struct Post {
    title: String,
    author: User,
}

let mut registry = TypeRegistry::new();
registry.register::<Post>();

// Renders types in dependency order
let output = registry.render();
// type User = { id: string; name: string };
// type Post = { title: string; author: User };

Attributes

Container Attributes

Field Attributes

Advanced Features

Intersection Types

Extend existing TypeScript types:

#[derive(TS)]
#[ts(extends = "BaseEntity")]
struct User {
    name: String,
    email: String,
}
// Renders as: type User = BaseEntity & { name: string; email: string }

Template Literals

Generate branded ID types:

#[derive(TS)]
struct Order {
    #[ts(pattern = "order-${string}")]
    id: String,
}
// Renders as: id: `order-${string}`

Indexed Access

Reference nested type properties:

#[derive(TS)]
struct Comment {
    #[ts(index = "User", key = "id")]
    author_id: String,
}
// Renders as: author_id: User["id"]

Rename Conventions

Supported values for rename_all: camelCase, PascalCase, snake_case, SCREAMING_SNAKE_CASE, kebab-case, SCREAMING-KEBAB-CASE

Type Mappings

License

MIT