fix: allow svg canvas size modification (#928)

* fix(SvgCanvas): allow canvas size modification

* test: add tests

__test__/svg-canvas.spec.ts

@@ -12,6 +12,15 @@ test.beforeEach((t) => {
   t.context.canvas = createCanvas(1024, 768, SvgExportFlag.ConvertTextToPaths)
 })
 
+test('should be able to adjust size', (t) => {
+  const { canvas } = t.context
+  canvas.width = 512
+  canvas.height = 384
+
+  t.is(canvas.width, 512)
+  t.is(canvas.height, 384)
+})
+
 test('should be able to export path/arc/rect', (t) => {
   const { canvas } = t.context
   const ctx = canvas.getContext('2d')

src/lib.rs

@@ -531,6 +531,42 @@ impl<'scope> SVGCanvas<'scope> {
       })
     }
   }
+
+  #[napi(setter)]
+  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(
+      &mut self.ctx.context,
+      Context::new(width, height, ColorSpace::default())?,
+    );
+    env.adjust_external_memory((width as i64 - old_ctx.width as i64) * 4)?;
+    Ok(())
+  }
+
+  #[napi(getter)]
+  pub fn get_width(&self) -> u32 {
+    self.width
+  }
+
+  #[napi(setter)]
+  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(
+      &mut self.ctx.context,
+      Context::new(width, height, ColorSpace::default())?,
+    );
+    env.adjust_external_memory((height as i64 - old_ctx.height as i64) * 4)?;
+    Ok(())
+  }
+
+  #[napi(getter)]
+  pub fn get_height(&self) -> u32 {
+    self.height
+  }
 }
 
 #[napi]

src/path.rs

@@ -298,7 +298,7 @@ impl Path {
   #[napi(js_name = "toSVGString")]
   pub fn to_svg_string(&self, env: Env) -> Result<JsString> {
     let sk_string = self.inner.to_svg_string();
-    unsafe { env.create_string_from_c_char(sk_string.ptr, sk_string.length) }
+    unsafe { env.create_string_from_c_char(sk_string.ptr, sk_string.length as isize) }
   }
 
   #[napi]