napi@2.9.0

Core changes

as_object for ClassInstance

You can use the ClassInstance as Object on the Rust side and manipulate it.

#[napi]
impl CanvasElement {
  #[napi(constructor)]
  pub fn new(mut env: Env, mut this: This, width: u32, height: u32) -> Result<Self> {
    let ctx = CanvasRenderingContext2D::into_instance(
      CanvasRenderingContext2D {
        context: Context::new(width, height, ColorSpace::default())?,
      },
      env,
    )?;
    ctx.as_object(env).define_properties(&[
      Property::new(FILL_STYLE_HIDDEN_NAME)?
        .with_value(&env.create_string("#000")?)
        .with_property_attributes(PropertyAttributes::Writable | PropertyAttributes::Configurable),
      Property::new(STROKE_STYLE_HIDDEN_NAME)?
        .with_value(&env.create_string("#000")?)
        .with_property_attributes(PropertyAttributes::Writable | PropertyAttributes::Configurable),
    ])?;
    env.adjust_external_memory((width * height * 4) as i64)?;
    this.define_properties(&[Property::new("ctx")?
      .with_value(&ctx)
      .with_property_attributes(PropertyAttributes::Default)])?;
    Ok(Self { width, height, ctx })
  }
}

as_unknown for Either types

For the scenario that preserves original JavaScript values in Either types and sets them into object property, and retrieves it back in the other place.

  #[napi(getter)]
  pub fn get_fill_style(&self, this: This) -> Result<Unknown> {
    this.get_named_property_unchecked(FILL_STYLE_HIDDEN_NAME)
  }

  #[napi(setter, return_if_invalid)]
  pub fn set_fill_style(
    &mut self,
    env: Env,
    mut this: This,
    fill_style: Either3<JsString, ClassInstance<CanvasGradient>, ClassInstance<CanvasPattern>>,
  ) -> Result<()> {
    // ... some logic
    let raw_fill_style = fill_style.as_unknown(env);  
    this.set(FILL_STYLE_HIDDEN_NAME, &raw_fill_style)?;
    Ok(())
  }

ToNapiValue for f32

You can use f32 as the return type:

#[napi]
pub fn return_f32() -> f32 {
  3.14
}

What's Changed

• fix(napi): segfault when ThreadsafeFunction's callback closure captures data by @messense in #1281
• feat(napi): implement as_object and validate for ClassInstance by @Brooooooklyn in #1284
• feat(napi): implement as_unknown and validate for Either types by @Brooooooklyn in #1285
• feat(napi): implement ToNapiValue for f32 by @Brooooooklyn in #1286

New Contributors

• @JSerFeng made their first contribution in #1278

Full Changelog: https://github.com/napi-rs/napi-rs/compare/napi-derive@2.8.0...napi@2.9.0