fix: Creating canvas with width or height of zero or less (#739)

* fix: Creating canvas with width or height of zero or less

* test: createCanvas default sizes for non-positive values

* fix

---------

Co-authored-by: LongYinan <[email protected]>

__test__/canvas-class.spec.ts

@@ -23,5 +23,22 @@ test('ctx.canvas should be equal to canvas', (t) => {
 test('[SVG] ctx.canvas should be equal to canvas', (t) => {
  const canvas = createCanvas(100, 100, SvgExportFlag.NoPrettyXML)
  const ctx = canvas.getContext('2d')
+ // @ts-expect-error
  t.is(ctx.canvas, canvas)
 })
+
+test('Canvas size should equal 350x150 when provided non-positive values', (t) => {
+ let canvas = createCanvas(0, 0)
+ t.is(canvas.width, 350)
+ t.is(canvas.height, 150)
+ canvas = createCanvas(-1, 10)
+ t.is(canvas.width, 350)
+ t.is(canvas.height, 10)
+ canvas = createCanvas(10, -10)
+ t.is(canvas.height, 150)
+ t.is(canvas.width, 10)
+
+ const svgCanvas = createCanvas(10, -10, SvgExportFlag.ConvertTextToPaths)
+ t.is(svgCanvas.height, 150)
+ t.is(svgCanvas.width, 10)
+})

src/lib.rs

@@ -103,7 +103,10 @@ impl<'scope> CanvasElement<'scope> {
  }
 
  #[napi(constructor)]
- pub fn new(env: &Env, mut this: This, width: u32, height: u32) -> Result<Self> {
+ pub fn new(env: &Env, mut this: This, width: i32, height: i32) -> Result<Self> {
+ // Default fallback of canvas on browser and skia-canvas is 350x150
+ let width = (if width <= 0 { 350 } else { width }) as u32;
+ let height = (if height <= 0 { 150 } else { height }) as u32;
  let ctx = Self::create_context(env, width, height)?;
  let ctx = ctx.assign_to_this_with_attributes("ctx", PropertyAttributes::Default, &mut this)?;
  let mut ctx_obj = ctx.as_object(env);
@@ -116,7 +119,8 @@ impl<'scope> CanvasElement<'scope> {
  }
 
  #[napi(setter)]
- pub fn set_width(&mut self, env: Env, width: u32) -> Result<()> {
+ pub fn set_width(&mut self, env: Env, width: i32) -> Result<()> {
+ let width = (if width <= 0 { 350 } else { width }) as u32;
  self.width = width;
  let height = self.height;
  let old_ctx = mem::replace(
@@ -133,7 +137,8 @@ impl<'scope> CanvasElement<'scope> {
  }
 
  #[napi(setter)]
- pub fn set_height(&mut self, env: Env, height: u32) -> Result<()> {
+ pub fn set_height(&mut self, env: Env, height: i32) -> Result<()> {
+ let height = (if height <= 0 { 150 } else { height }) as u32;
  self.height = height;
  let width = self.width;
  let old_ctx = mem::replace(
@@ -444,10 +449,13 @@ impl<'scope> SVGCanvas<'scope> {
  pub fn new(
  env: &Env,
  mut this: This,
- width: u32,
- height: u32,
+ width: i32,
+ height: i32,
  flag: SvgExportFlag,
  ) -> Result<SVGCanvas<'scope>> {
+ // Default fallback of canvas on browser and skia-canvas is 350x150
+ let width = (if width <= 0 { 350 } else { width }) as u32;
+ let height = (if height <= 0 { 150 } else { height }) as u32;
  let ctx = CanvasRenderingContext2D::into_instance(
  CanvasRenderingContext2D {
  context: Context::new_svg(width, height, flag.into(), ColorSpace::default())?,