napi-rs

This project was initialized from xray

A minimal library for building compiled NodeJS add-ons in Rust.

Platform Support

Operating Systems

| Linux | macOS | Windows MSVC | FreeBSD | | ----- | ----- | ------------ | ------- | | ✓ | ✓ | ✓ | ✓ |

NodeJS

| Node10 | Node 12 | Node14 | | ------ | ------- | ------ | | ✓ | ✓ | ✓ |

This library depends on N-API and requires [email protected] or later.

We already have some packages written by napi-rs: node-rs

One nice feature is that this crate allows you to build add-ons purely with the Rust toolchain and without involving node-gyp.

Taste

You can start from package-template to play with napi-rs

Define JavaScript functions

#[js_function(1)] // ------> arguments length, omit for zero
fn fibonacci(ctx: CallContext) -> Result<JsNumber> {
  let n = ctx.get::<JsNumber>(0)?.try_into()?;
  ctx.env.create_int64(fibonacci_native(n))
}

#[inline]
fn fibonacci_native(n: i64) -> i64 {
  match n {
    1 | 2 => 1,
    _ => fibonacci_native(n - 1) + fibonacci_native(n - 2),
  }
}

Register module

/// test_module is Module name
register_module!(test_module, init);

/// Module is `module` object in NodeJS
fn init(module: &mut Module) -> Result<()> {
  module.create_named_method("fibonacci", fibonacci)?;
}

Building

This repository is a Cargo crate. Any napi-based add-on should contain Cargo.toml to make it a Cargo crate.

In your Cargo.toml you need to set the crate-type to "cdylib" so that cargo builds a C-style shared library that can be dynamically loaded by the Node executable. You'll also need to add this crate as a dependency.

[lib]
crate-type = ["cdylib"]

[dependencies]
napi = "0.5"
napi-derive = "0.5"

[build-dependencies]
napi-build = "0.2"

And create build.rs in your own project:

// build.rs
extern crate napi_build;

fn main() {
  napi_build::setup();
}

So far, the napi build script has only been tested on macOS Linux and Windows x64 MSVC.

See the included test_module for an example add-on.

Run cargo build to produce the Dynamic lib file. And install the napi-rs to help you copy Dynamic lib file to .node file in case you can require it in your program.

{
  "package": "your pkg",
  "devDependencies": {
    "napi-rs": "latest"
  },
  "scripts": {
    "build": "cargo build && napi build",
    "build-release": "cargo build --release && napi build --release"
  }
}

Then you can require your native binding:

require('./target/debug|release/[module_name].node')

The module_name would be your package name in your Cargo.toml.

xxx => ./target/debug|release/xxx.node

xxx-yyy => ./target/debug|release/xxx_yyy.node

You can also copy Dynamic lib file to an appointed location:

napi build [--release] .
napi build [--release] ./mylib

Testing

Because libraries that depend on this crate must be loaded into a Node executable in order to resolve symbols, all tests are written in JavaScript in the test_module subdirectory.

To run tests:

yarn build:test
yarn test

Features table

Create JavaScript values

| NAPI | NAPI Version | Minimal Node version | Status | | ------------------------------------------------------------------------------------------------------------ | ------------ | -------------------- | ------ | | napi_create_array | 1 | v8.0.0 | ✅ | | napi_create_array_with_length | 1 | v8.0.0 | ✅ | | napi_create_arraybuffer | 1 | v8.0.0 | ✅ | | napi_create_buffer | 1 | v8.0.0 | ✅ | | napi_create_buffer_copy | 1 | v8.0.0 | ✅ | | napi_create_date | 5 | v11.11.0 | ✅ | | napi_create_external | 1 | v8.0.0 | ✅ | | napi_create_external_arraybuffer | 1 | v8.0.0 | ✅ | | napi_create_external_buffer | 1 | v8.0.0 | ✅ | | napi_create_object | 1 | v8.0.0 | ✅ | | napi_create_symbol | 1 | v8.0.0 | ✅ | | napi_create_typedarray | 1 | v8.0.0 | ✅ | | napi_create_dataview | 1 | v8.3.0 | ✅ | | napi_create_int32 | 1 | v8.4.0 | ✅ | | napi_create_uint32 | 1 | v8.4.0 | ✅ | | napi_create_int64 | 1 | v8.4.0 | ✅ | | napi_create_double | 1 | v8.4.0 | ✅ | | napi_create_bigint_int64 | 6 | v10.7.0 | ✅ | | napi_create_bigint_uint64 | 6 | v10.7.0 | ✅ | | napi_create_bigint_words | 6 | v10.7.0 | ✅ | | napi_create_string_latin1 | 1 | v8.0.0 | ✅ | | napi_create_string_utf16 | 1 | v8.0.0 | ✅ | | napi_create_string_utf8 | 1 | v8.0.0 | ✅ |

Functions to convert from N-API to C types

| NAPI | NAPI Version | Minimal Node Version | Status | | ---------------------------------------------------------------------------------------------------- | ------------ | -------------------- | ------ | | napi_get_array_length | 1 | v8.0.0 | ✅ | | napi_get_arraybuffer_info | 1 | v8.0.0 | ✅ | | napi_get_buffer_info | 1 | v8.0.0 | ✅ | | napi_get_prototype | 1 | v8.0.0 | ✅ | | napi_get_typedarray_info | 1 | v8.0.0 | ✅ | | napi_get_dataview_info | 1 | v8.3.0 | ✅ | | napi_get_date_value | 5 | v11.11.0 | ✅ | | napi_get_value_bool | 1 | v8.0.0 | ✅ | | napi_get_value_double | 1 | v8.0.0 | ✅ | | napi_get_value_bigint_int64 | 6 | v10.7.0 | ✅ | | napi_get_value_bigint_uint64 | 6 | v10.7.0 | ✅ | | napi_get_value_bigint_words | 6 | v10.7.0 | ✅ | | napi_get_value_external | 1 | v8.0.0 | ✅ | | napi_get_value_int32 | 1 | v8.0.0 | ✅ | | napi_get_value_int64 | 1 | v8.0.0 | ✅ | | napi_get_value_string_latin1 | 1 | v8.0.0 | ✅ | | napi_get_value_string_utf8 | 1 | v8.0.0 | ✅ | | napi_get_value_string_utf16 | 1 | v8.0.0 | ✅ | | napi_get_value_uint32 | 1 | v8.0.0 | ✅ | | napi_get_boolean | 1 | v8.0.0 | ✅ | | napi_get_global | 1 | v8.0.0 | ✅ | | napi_get_null | 1 | v8.0.0 | ✅ | | napi_get_undefined | 1 | v8.0.0 | ✅ |

Working with JavaScript Values and Abstract Operations

| NAPI | NAPI Version | Minimal Node Version | Status | | ---------------------------------------------------------------------------------------------------- | ------------ | -------------------- | ------ | | napi_coerce_to_bool | 1 | v8.0.0 | ✅ | | napi_coerce_to_number | 1 | v8.0.0 | ✅ | | napi_coerce_to_object | 1 | v8.0.0 | ✅ | | napi_coerce_to_string | 1 | v8.0.0 | ✅ | | napi_typeof | 1 | v8.0.0 | ✅ | | napi_instanceof | 1 | v8.0.0 | ✅ | | napi_is_array | 1 | v8.0.0 | ✅ | | napi_is_arraybuffer | 1 | v8.0.0 | ✅ | | napi_is_buffer | 1 | v8.0.0 | ✅ | | napi_is_date | 1 | v8.0.0 | ✅ | | napi_is_error | 1 | v8.0.0 | ✅ | | napi_is_typedarray | 1 | v8.0.0 | ✅ | | napi_is_dataview | 1 | v8.3.0 | ✅ | | napi_strict_equals | 1 | v8.0.0 | ✅ | | napi_detach_arraybuffer | 7 | v13.3.0 | ✅ | | napi_is_detached_arraybuffer | 7 | v13.3.0 | ✅ |