# napi-rs > This project was initialized from [xray](https://github.com/atom/xray) A minimal library for building compiled `NodeJS` add-ons in `Rust`.

# Platform Support ![Lint](https://github.com/napi-rs/napi-rs/workflows/Lint/badge.svg) ![Linux N-API@3](https://github.com/napi-rs/napi-rs/workflows/Linux%20N-API@3/badge.svg) ![Linux musl](https://github.com/napi-rs/napi-rs/workflows/Linux%20musl/badge.svg) ![macOS/Windows/Linux x64](https://github.com/napi-rs/napi-rs/workflows/macOS/Windows/Linux%20x64/badge.svg) ![Linux-aarch64](https://github.com/napi-rs/napi-rs/workflows/Linux-aarch64/badge.svg) ![Linux-armv7](https://github.com/napi-rs/napi-rs/workflows/Linux-armv7/badge.svg) ![macOS-Android](https://github.com/napi-rs/napi-rs/workflows/macOS-Android/badge.svg) ![Windows i686](https://github.com/napi-rs/napi-rs/workflows/Windows%20i686/badge.svg) [![FreeBSD](https://api.cirrus-ci.com/github/napi-rs/napi-rs.svg)](https://cirrus-ci.com/github/napi-rs/napi-rs?branch=main) ## Operating Systems | Linux | macOS | Windows MSVC | FreeBSD | | ----- | ----- | ------------ | ------- | | ✓ | ✓ | ✓ | ✓ | ## NodeJS | Node10 | Node 12 | Node14 | Node15 | | ------ | ------- | ------ | ------ | | ✓ | ✓ | ✓ | ✓ | This library depends on N-API and requires `Node@10.0.0` or later. We already have some packages written by `napi-rs`: [node-rs](https://github.com/napi-rs/node-rs) One nice feature is that this crate allows you to build add-ons purely with the `Rust/JavaScript` toolchain and without involving `node-gyp`. ## Taste > You can start from [package-template](https://github.com/napi-rs/package-template) to play with `napi-rs` ### Define JavaScript functions ```rust #[js_function(1)] // ------> arguments length, omit for zero fn fibonacci(ctx: CallContext) -> Result { let n = ctx.get::(0)?.try_into()?; ctx.env.create_int64(fibonacci_native(n)) } #[inline(always)] fn fibonacci_native(n: i64) -> i64 { match n { 1 | 2 => 1, _ => fibonacci_native(n - 1) + fibonacci_native(n - 2), } } ``` ### Register module ```rust use napi::{JsObject, Result}; /// `exports` is `module.exports` object in NodeJS #[module_exports] fn init(mut exports: JsObject) -> Result<()> { exports.create_named_method("fibonacci", fibonacci)?; } ``` And you can also create `JavaScript` value while registering module: ```rust use napi::{JsObject, Result, Env}; #[module_exports] fn init(mut exports: JsObject, env: Env) -> Result<()> { exports.create_named_method("fibonacci", fibonacci)?; exports.set_named_property("DEFAULT_VALUE", env.create_int64(100)?)?; } ``` ## 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. ```toml [package] name = "awesome" [lib] crate-type = ["cdylib"] [dependencies] napi = "1.0" napi-derive = "1.0" [build-dependencies] napi-build = "1.0" ``` And create `build.rs` in your own project: ```rust // build.rs extern crate napi_build; fn main() { napi_build::setup(); } ``` So far, the `napi` build script has only been tested on `macOS` `Linux` `Windows x64 MSVC` and `FreeBSD`. See the included [test_module](./test_module) for an example add-on. Install the `@napi-rs/cli` to help you build your `Rust` codes and copy `Dynamic lib` file to `.node` file in case you can `require` it in your program. ```js { "package": "awesome-package", "devDependencies": { "@napi-rs/cli": "^1.0.0" }, "napi": { "name": "jarvis" // <----------- Config the name of native addon, or the napi command will use the name of `Cargo.toml` for the binary file name. }, "scripts": { "build": "napi build --release", "build:debug": "napi build" } } ``` Then you can require your native binding: ```js require('./jarvis.node') ``` The `module_name` would be your `package` name in your `Cargo.toml`. `xxx => ./xxx.node` `xxx-yyy => ./xxx_yyy.node` You can also copy `Dynamic lib` file to an appointed location: ```bash napi build [--release] ./dll napi build [--release] ./artifacts ``` There are [documents](./cli) which contains more details about the `@napi-rs/cli` usage. ## 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: ```sh yarn build:test yarn test ``` ## Features table ### Create JavaScript values | NAPI | NAPI Version | Minimal Node version | Status | | ------------------------------------------------------------------------------------------------------------ | ------------ | -------------------- | ------ | | [napi_create_array](https://nodejs.org/api/n-api.html#n_api_napi_create_array) | 1 | v8.0.0 | ✅ | | [napi_create_array_with_length](https://nodejs.org/api/n-api.html#n_api_napi_create_array_with_length) | 1 | v8.0.0 | ✅ | | [napi_create_arraybuffer](https://nodejs.org/api/n-api.html#n_api_napi_create_arraybuffer) | 1 | v8.0.0 | ✅ | | [napi_create_buffer](https://nodejs.org/api/n-api.html#n_api_napi_create_buffer) | 1 | v8.0.0 | ✅ | | [napi_create_buffer_copy](https://nodejs.org/api/n-api.html#n_api_napi_create_buffer_copy) | 1 | v8.0.0 | ✅ | | [napi_create_date](https://nodejs.org/api/n-api.html#n_api_napi_create_date) | 5 | v11.11.0 | ✅ | | [napi_create_external](https://nodejs.org/api/n-api.html#n_api_napi_create_external) | 1 | v8.0.0 | ✅ | | [napi_create_external_arraybuffer](https://nodejs.org/api/n-api.html#n_api_napi_create_external_arraybuffer) | 1 | v8.0.0 | ✅ | | [napi_create_external_buffer](https://nodejs.org/api/n-api.html#n_api_napi_create_external_buffer) | 1 | v8.0.0 | ✅ | | [napi_create_object](https://nodejs.org/api/n-api.html#n_api_napi_create_object) | 1 | v8.0.0 | ✅ | | [napi_create_symbol](https://nodejs.org/api/n-api.html#n_api_napi_create_symbol) | 1 | v8.0.0 | ✅ | | [napi_create_typedarray](https://nodejs.org/api/n-api.html#n_api_napi_create_typedarray) | 1 | v8.0.0 | ✅ | | [napi_create_dataview](https://nodejs.org/api/n-api.html#n_api_napi_create_dataview) | 1 | v8.3.0 | ✅ | | [napi_create_int32](https://nodejs.org/api/n-api.html#n_api_napi_create_int32) | 1 | v8.4.0 | ✅ | | [napi_create_uint32](https://nodejs.org/api/n-api.html#n_api_napi_create_uint32) | 1 | v8.4.0 | ✅ | | [napi_create_int64](https://nodejs.org/api/n-api.html#n_api_napi_create_int64) | 1 | v8.4.0 | ✅ | | [napi_create_double](https://nodejs.org/api/n-api.html#n_api_napi_create_double) | 1 | v8.4.0 | ✅ | | [napi_create_bigint_int64](https://nodejs.org/api/n-api.html#n_api_napi_create_bigint_int64) | 6 | v10.7.0 | ✅ | | [napi_create_bigint_uint64](https://nodejs.org/api/n-api.html#n_api_napi_create_bigint_uint64) | 6 | v10.7.0 | ✅ | | [napi_create_bigint_words](https://nodejs.org/api/n-api.html#n_api_napi_create_bigint_words) | 6 | v10.7.0 | ✅ | | [napi_create_string_latin1](https://nodejs.org/api/n-api.html#n_api_napi_create_string_latin1) | 1 | v8.0.0 | ✅ | | [napi_create_string_utf16](https://nodejs.org/api/n-api.html#n_api_napi_create_string_utf16) | 1 | v8.0.0 | ✅ | | [napi_create_string_utf8](https://nodejs.org/api/n-api.html#n_api_napi_create_string_utf8) | 1 | v8.0.0 | ✅ | ### [Functions to convert from N-API to C types](https://nodejs.org/api/n-api.html#n_api_functions_to_convert_from_n_api_to_c_types) | NAPI | NAPI Version | Minimal Node Version | Status | | ---------------------------------------------------------------------------------------------------- | ------------ | -------------------- | ------ | | [napi_get_array_length](https://nodejs.org/api/n-api.html#n_api_napi_get_array_length) | 1 | v8.0.0 | ✅ | | [napi_get_arraybuffer_info](https://nodejs.org/api/n-api.html#n_api_napi_get_arraybuffer_info) | 1 | v8.0.0 | ✅ | | [napi_get_buffer_info](https://nodejs.org/api/n-api.html#n_api_napi_get_buffer_info) | 1 | v8.0.0 | ✅ | | [napi_get_prototype](https://nodejs.org/api/n-api.html#n_api_napi_get_prototype) | 1 | v8.0.0 | ✅ | | [napi_get_typedarray_info](https://nodejs.org/api/n-api.html#n_api_napi_get_typedarray_info) | 1 | v8.0.0 | ✅ | | [napi_get_dataview_info](https://nodejs.org/api/n-api.html#n_api_napi_get_dataview_info) | 1 | v8.3.0 | ✅ | | [napi_get_date_value](https://nodejs.org/api/n-api.html#n_api_napi_get_date_value) | 5 | v11.11.0 | ✅ | | [napi_get_value_bool](https://nodejs.org/api/n-api.html#n_api_napi_get_value_bool) | 1 | v8.0.0 | ✅ | | [napi_get_value_double](https://nodejs.org/api/n-api.html#n_api_napi_get_value_double) | 1 | v8.0.0 | ✅ | | [napi_get_value_bigint_int64](https://nodejs.org/api/n-api.html#n_api_napi_get_value_bigint_int64) | 6 | v10.7.0 | ✅ | | [napi_get_value_bigint_uint64](https://nodejs.org/api/n-api.html#n_api_napi_get_value_bigint_uint64) | 6 | v10.7.0 | ✅ | | [napi_get_value_bigint_words](https://nodejs.org/api/n-api.html#n_api_napi_get_value_bigint_words) | 6 | v10.7.0 | ✅ | | [napi_get_value_external](https://nodejs.org/api/n-api.html#n_api_napi_get_value_external) | 1 | v8.0.0 | ✅ | | [napi_get_value_int32](https://nodejs.org/api/n-api.html#n_api_napi_get_value_int32) | 1 | v8.0.0 | ✅ | | [napi_get_value_int64](https://nodejs.org/api/n-api.html#n_api_napi_get_value_int64) | 1 | v8.0.0 | ✅ | | [napi_get_value_string_latin1](https://nodejs.org/api/n-api.html#n_api_napi_get_value_string_latin1) | 1 | v8.0.0 | ✅ | | [napi_get_value_string_utf8](https://nodejs.org/api/n-api.html#n_api_napi_get_value_string_utf8) | 1 | v8.0.0 | ✅ | | [napi_get_value_string_utf16](https://nodejs.org/api/n-api.html#n_api_napi_get_value_string_utf16) | 1 | v8.0.0 | ✅ | | [napi_get_value_uint32](https://nodejs.org/api/n-api.html#n_api_napi_get_value_uint32) | 1 | v8.0.0 | ✅ | | [napi_get_boolean](https://nodejs.org/api/n-api.html#n_api_napi_get_boolean) | 1 | v8.0.0 | ✅ | | [napi_get_global](https://nodejs.org/api/n-api.html#n_api_napi_get_global) | 1 | v8.0.0 | ✅ | | [napi_get_null](https://nodejs.org/api/n-api.html#n_api_napi_get_null) | 1 | v8.0.0 | ✅ | | [napi_get_undefined](https://nodejs.org/api/n-api.html#n_api_napi_get_undefined) | 1 | v8.0.0 | ✅ | ### [Working with JavaScript Values and Abstract Operations](https://nodejs.org/api/n-api.html#n_api_working_with_javascript_values_and_abstract_operations) | NAPI | NAPI Version | Minimal Node Version | Status | | ---------------------------------------------------------------------------------------------------- | ------------ | -------------------- | ------ | | [napi_coerce_to_bool](https://nodejs.org/api/n-api.html#n_api_napi_coerce_to_bool) | 1 | v8.0.0 | ✅ | | [napi_coerce_to_number](https://nodejs.org/api/n-api.html#n_api_napi_coerce_to_number) | 1 | v8.0.0 | ✅ | | [napi_coerce_to_object](https://nodejs.org/api/n-api.html#n_api_napi_coerce_to_object) | 1 | v8.0.0 | ✅ | | [napi_coerce_to_string](https://nodejs.org/api/n-api.html#n_api_napi_coerce_to_string) | 1 | v8.0.0 | ✅ | | [napi_typeof](https://nodejs.org/api/n-api.html#n_api_napi_typeof) | 1 | v8.0.0 | ✅ | | [napi_instanceof](https://nodejs.org/api/n-api.html#n_api_napi_instanceof) | 1 | v8.0.0 | ✅ | | [napi_is_array](https://nodejs.org/api/n-api.html#n_api_napi_is_array) | 1 | v8.0.0 | ✅ | | [napi_is_arraybuffer](https://nodejs.org/api/n-api.html#n_api_napi_is_arraybuffer) | 1 | v8.0.0 | ✅ | | [napi_is_buffer](https://nodejs.org/api/n-api.html#n_api_napi_is_buffer) | 1 | v8.0.0 | ✅ | | [napi_is_date](https://nodejs.org/api/n-api.html#n_api_napi_is_date) | 1 | v8.0.0 | ✅ | | [napi_is_error](https://nodejs.org/api/n-api.html#n_api_napi_is_error_1) | 1 | v8.0.0 | ✅ | | [napi_is_typedarray](https://nodejs.org/api/n-api.html#n_api_napi_is_typedarray) | 1 | v8.0.0 | ✅ | | [napi_is_dataview](https://nodejs.org/api/n-api.html#n_api_napi_is_dataview) | 1 | v8.3.0 | ✅ | | [napi_strict_equals](https://nodejs.org/api/n-api.html#n_api_napi_strict_equals) | 1 | v8.0.0 | ✅ | | [napi_detach_arraybuffer](https://nodejs.org/api/n-api.html#n_api_napi_detach_arraybuffer) | 7 | v13.3.0 | ✅ | | [napi_is_detached_arraybuffer](https://nodejs.org/api/n-api.html#n_api_napi_is_detached_arraybuffer) | 7 | v13.3.0 | ✅ |